Is there any similarities between two kinds of scientists, which includes one type is arrogant, intelligent and powerful and the other type is calm, smart and strong.... And one answer can be their madness to learn the topic or to understand the whole matter makes them similar....
Scientists are very excellent in facing failures and rising again after that failure which every scientist would have faced somewhere sometime in their experiment.
The agar agar is called twice because the word agar is derived from agar - agar which is the malay name for red alage which is known as gigartina giacilaria
Sir once you asked that I'm growth curve during death phase there decline the line but the cells remain constant so why did the curve showed decline. The reason is that the dead bacteria settles down so that the light is not passed through them nd so they show decline phase
In death phase, cell number or cell mass concentration drop after death because of the autolysis, cell membrane is damage and cytoplasm leaks out, as a result refractive index decreases and also particulate matters decreases and therefore OD drops because of smaller scattering of light.
Sir once you asked that I'm growth curve during death phase there decline the line but the cells remain constant so why did the curve showed decline. The reason is that the dead bacteria settles down so that the light is not passed through them nd so they show decline phase
During decline phase the bacterial cells either settle down or they undergo cell death. There are two hypothesis through which it can be explained. The first one is programmed cell survival wherein the cells, undergo s dormant stage, in which the cell is viable but is non-culturable. Whereas the other method is in which the cell undergoes programmed cell death leading to autolysis and death. The decision of choosing path depends on individual cells. The lysed cells leak their cellular content out in medium which is used by the unlysed cells. Hence due to autolysis the optical density decreases as the cells are dying. Also the rate of growth is lesser than the rate of decline or death hence the OD is lower.
A question was asked why most of the organisms reside in large intestine?Ans is that the bacterial population in the large intestine digest carbohydrates, proteins and lipids that escape digestion and absorption in small intestine.So the normal sugars get absorb in small intestine.
According to me the answer should be, gut microbes release certain metabolites which human body is unable to synthesise and also they help in absorption,as ileum and large intestine are the sites for absorption of substances, say for example lactobacillus help in absorption of tryptophan.
Yes it can be both because many of the microbes form certain metabolites but most of the fermenting sugars are also important for humans and certain byproducts too.There are many different answers.
QUESTION: Why decline phase have decreased O.D. value?
ANSWER: dead gram+ bacteria lysed (autolysis). SO concentration of cells really decrease. in the case of gram-, before lysis dead cells swell (refractive index decrease). this process also leads to decrease in O.D. most of the time O.D. of bacteria decrease due to autolysis but be very careful the O.D. value can be constant when medium is less toxic and autolysis very low.
Generation time and line of curve are relevant to each other but the generation depend on the slop which shows the time laps which taken for calculation. So in the comparison it may be verry so this situation happen
Synchronous culture is the cell culture where is showing the cells that all are in same growth rate . There are many factors that affects the cell cycle basically normal cultures have cells in all phages of cell cycle synchronous cultures can be obtained in many ways like it can be obtained by changing the external conditions as to arrest the growth of all cells in the culture the second option is by adding chemicals like growth inhibitors,after growth has completely stopped for all cells the inhibitors can be removed from the culture the cells will than begin to grow in synchronous culture
Ans:Its not stable In the new study, researchers calculated past atmospheric oxygen levels by looking at air trapped inside ancient polar ice samples. Specifically, they looked at samples from Greenland and Antarctica.
The new estimates suggest that atmospheric oxygen levels have fallen by 0.7 percent over the past 800,000 years. The scientists concluded that oxygen sinks — processes that removed oxygen from the air — were about 1.7 percent larger than oxygen sources during this time.
When the life bigin on earth there was no usage of oxygen because the aerobic life not take place. After the evolution of cell than the oxygen utilized. At same time the oxygen is generated by cynobacteria, algae and higher plants.in this way the oxygen levwl is constant on earth.
If microorganisms get disappeared how our world would be?(19MMB027) 1 Microorganisms play a crucial role in decomposition of organic matters both in soil and ocean so first of all accumulation of such matters will increase on earth. 2 Cyanobacteria can convert atmospheric nitrogen into ammonium and nitrate ions that can be easily absorbed by the plants for their growth and we consume plants for energy so this process will result into improper growth of both. 3 The microorganisms helping in removal of pollutants by utilizing it as their substrate and indirectly helping us and so pollution will arise and will keep arising more and more in their absence. 4 Our immune system would become weak and it will affect upcoming generation also.
The oxygen level when the earth formed was zero, then the first life form occurred in the form of cyanobacteria and they started forming free oxygen in environment by utilising certain compounds like carbon dioxide, sulphur oxides, iron as their energy source and oxygen was observed in atmosphere ,slowly it increased upto certain concentration and that bacteria started using that oxygen and evolving in that environment. Now, today there is 21% oxygen which is maintained because of certain reasons like global warming, tectonic movement, etc. Diatoms also play major role, as they are responsible to maintain oxygen level in atmosphere. Also if the oxygen is increased in atmosphere, it will support combustion and oxygen takes part in the burning reaction. By considering certain parameters some increase oxygen concentration, while some decreases. Thus oxygen amount is maintained.
What would be the earth without microorganisms? (-by udita pal 19MBT028) Well life in earth will not be possible without microorganisms. As microorganisms are very useful in many ways. They are efficient recyclers as they play a critical role in decomposing organic matter. 2.Also there are microorganisms those play an important role in fixing nitrogen and make them available to plants for their survival. 3. Microorganism also play an important role to fight pollution.As bioremediation uses certain bacteria that digest toxic substance and convert them into less harmful substance. There are certain bacteria residing in our digestive system that are good gut bacteria and essential for the body.
The reason why the oxygen percentage is constant for many years is because that the green plants who are capable of photosynthesis are taking up CO2 and producing 02 in exchange, Amazon forest are said to be responsible for 20% of the world's Oxygen and there are also called lungs of earth Some Oxygen is also made when ozone molecules are broke by UV rays of sun 1) access O2 produced but absorbed in ocean and seabed rock in form of iron oxide on the sea floor 2)O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer. So this way o2 is stable But right now o2 level slightly decrease because of industrial co2 production. And O2 level directly depend on co2...
Queen:which enzyme is fastest enzyme? Ans:Carbonic anhydrase .Enzyme activity depends on turnover number and carbonic anhydrase's turnover number is 4×b10000000.(19mmb028)
Why oxygen level is stable in atmosphere?(-by Dinky Motwani 19MMB015) Oxygen level is stable in atmosphere because the green plants who are capable of photosynthesis are taking up CO2 and producing O2 in exchange. Amazon Forest are said to be responsible for 20% of the world's oxygen. The content of oxygen mainly depends on the content of CO2.
Why oxygen level is stable in the earth? Ans. Oxygen levels first rised from 2-4 percent to 21 percent a few billion years ago. Actually the oxygen levels are depleting at a very slow rate that the rate of depletion seems negligible. The photosynthetic bacteria and other microorganisms like algae provide a huge amount of oxygen. Apart from them, rainforests are the major source of oxygen. Apart from the photosynthetic organisms, there are organisms which reduce the iron, sulfur and nitrogen oxides thereby retaining the oxygen levels on the earth. Simultaneously the consumption of oxygen occurs in various ways. The degradation of dead organisms also releases oxygen thus percentage of oxygen is maintained on earth.
Que. Why agar is used twice in the name agar powder? Ans. Agar powder or agar is made up of two polysaccharides namely agarose and agaropectin. The agar agar may be named as such due to the presence of this two polysaccharides from which it is made. The agar powder is made from red algae known as agarophytes and it belongs to the rhodophyta group.
QUESTION:How does oxygen content in atmosphere remain constant at 21%? oxygen is regulated because an increase in oxygen increases the consumption of oxygen and/or decreases the rate of oxygen production. A decrease in oxygen has opposite effects. The % oxygen has varied a lot over the lifespan of the earth, but it is much like climate where it very seldom changes dramatically in a short amount of time (short in relation to the lifespan of earth) even some studies shows oxygen levels are decreasing globally due to fossil-fuel burning. but this change is very negligible.
QUESTION: Why agar powder also called agar-agar powder? The word "agar" originally comes from agar-agar, the Malay name for red algae (Gigartina, Gracilaria) from which the agar powder is produced. so agar powder also called as agar-agar powder.
QUESTION:Which bacteria have minimum generation time? The bacterium Vibrio natriegens can double with a generation time of less than 10 min.it is fastest growing bacterium known.
QUESTION:Why large intestine of human contain highest amount of microorganisms? large intestine have highest amount of microorganism because it provide more time to microorganisms to make good surface contact and establish better colonisation and also rich in nutrient compare to other area of body.
QUESTION:Which enzyme is fastest? The hydration of carbon dioxide is catalyzed by an enzyme—namely, carbonic anhydrase. The transfer of CO2 from the tissues into the blood and then to the alveolar air catalyzed by this enzyme. Carbonic anhydrase is fastest enzymes known. Each enzyme molecule can hydrate 10^6 molecules of CO2 per second. This catalyzed reaction is 10^7 times as fast as the uncatalyzed one.
Fastest growing Bacteria and also Microorganism on Earth is:- _C. perfringens_ generation time has been reported to be as rapid as 7.4 min in autoclaved ground beef in bacteria; While there are certain microorganisms such as _M. pyrifera_ are the fastest growing multicellular brown algae to grow at the speed of 2ft per day that means its generation time is in few seconds
QUESTION:Which is the largest bacterial cell? Thiomargarita namibiensis is the largest bacteria in present, with a diameter of 750 μm. Thiomargarita namibiensis are large enough to be visible to the naked eye.
QUESTION:What are the advantages for microbes being in biofilm? Biofilm is a strong and dynamic structure that confers a broad range of advantages to its members, such as adhesion/cohesion capabilities, mechanical properties, nutritional sources, metabolite exchange platform, cellular communication, protection and resistance to drugs. The EPS of the biofilm matrix is negatively charged and hydrophobic. These properties enable the biofilm to concentrate ions and dissolved organic carbon compounds from the oligotrophic bulk fluid. Thus biofilms can grow in nutrient conditions that do not permit the growth of planktonic cells.
QUESTION :- Symbiotic association found in 2019? Lichen like symbiotic association of fungi with bacteria. Filamentous hyphae with coccoidal cyanobacteria found im marine phosphorite of south china. It shows that fungi developed symbiotic partnership with photoautotrophs before evolution of algae and vascular plants.
QUESTION :- How microbes survive at higher depth of earth crust? In earth crust cracks, fractures and openings of rocks are observed. In this surface ground water is observed which is 1billion year old. When rock and ground water came into contact serpentinization occurs which release small amount of H2. The environment at this place is oligotrophic means lack of nutrients. Microbes which are observed they are autotrophic (chemolithoautotrophs) in nature. They utilize H2 as energy source and survive. Example : 1) Dethiobacter - H2 using bacteria 2) Dethiosulfatibacter 3) uncultured clostridium species. These all microbes are identified by 16S rRNA sequencing because they are not culturable. Scientists may assume that some CO2 using bacteria are may be present due to the fossils of plants and animals which provides carbon source.
19MBT009 (Devashri Gandhi) Why we use "Fresh Meat Of OX Heart as a medium?
As i read Ox heart meat is used with nutrient broth in the "Robertson's Cooked Meat Medium",
Robertson’s Cooked Meat (RCM) medium is used for the cultivation of aerobic, microaerophilic, and anaerobic microorganisms, especially Clostridium species. It is also known as Cooked Meat Broth (CMB) as it contains pieces of fat free minced cooked meat of ox heart and nutrient broth. It supports the growth of both spore-forming and non-spore forming obligate anaerobes and also differentiate between putrefactive and saccharolytic species.
Oxygen in culture media can be reduced by various agents such as glucose, thioglycollate, cooked meat pieces, cysteine and ascorbic acid.
Thioglycollate broth which contains nutrient broth and 1% thioglycollate is also used to cultivate anerobes
How "PUTREFYING BACTERIA" works in PUTREFACTION OF MILK?
As in unpasteurized milk, it contains various species of bacteria, yeasts, and molds. Initially, the dominant organism is the bacterium Lactococcus (Streptococcus) lactis, which breaks down the milk sugar lactose, forming lactic acid as an end-product (figure 30.4). The resulting acid inhibits the growth of most other organisms in the milk, and eventually enough acid is produced to prevent even the further growth of L. lactis. The acid sours the milk and also curdles it, a result of denaturation of the milk proteins. Bacterial species such as Lactobacillus casei and Lactobacillus bulgaricus can multiply in this highly acidic environment. These species metabolize any remaining sugar, forming more acid until their growth is also inhibited. Yeasts and molds, which grow very well in this highly acidic environment, then become the dominant group and convert the lactic acid into non-acidic products. Because most of the sugar has already been used, the streptococci and lactobacilli cannot resume multiplication since they require this substrate. Milk protein (casein) is still available and can be utilized for energy by bacteria of the spore-forming genus Bacillus, and some other bacteria, all of which secrete proteolytic enzymes that digest the protein. This breakdown of protein, known as putrefaction, yields a completely clear and very odorous product. The milk thus goes through a succession of changes with time, first souring and finally putrefying.
What is a "MICROBIAL MAT" Or "How MICROBIAL COMMUNITY by forming biofilms in MICROBIAL MAT looks like?
A microbial mat is a thick, dense, highly organized structure composed of distinct layers. Frequently they are green, pink, and black, which indicate the growth of different groups of microorganisms. The green layer is the uppermost and is typically composed of various species of cyanobacteria. The color is due to the photosynthetic pigments of these microbes. The pink layer directly below consists of purple sulfur bacteria. The light-harvesting pigments of these anoxygenic phototrophs can use wavelengths of light not collected by the cyanobacteria. The black layer at the bottom results from iron molecules reacting with hydrogen sulfide produced by a group of bacteria called sulfate-reducers. These obligate anaerobes oxidize the organic compounds produced by the photosynthetic bacteria growing in the upper layers of the mat, using sulfate as a terminal electron acceptor.
I can't attach the photo here as comment box not permitting me to do so. So anyone wants to see pic of Microbial pit can find it on google
What are the reasons for "Decrease in Growth rate after late log phase"?
1) first reason
Cells' activities shift as they enter in " late log phase", which marks the transition to stationary phase. This change occurs in response to multiple factors that are sure to be in a closed system, such as depletion of nutrients and formation of waste products. If the cells are able to form endospores, they initiate the process of sporulation. If they cannot, they "shrink" in preparation for the starvation conditions ahead. The cells become rounder in shape and more resistant to harmful chemicals and radiation. Changes in the composition of their cell wall and cytoplasmic membrane also occur. As their surrounding environment changes, cells begin synthesizing different enzymes and other proteins, which collectively give rise to a new group of metabolites, termed secondary metabolites. Commercially, the most important secondary metabolites are antibiotics. These compounds are produced by many bacterial spe. and inhibit the growth of or kill other organisms.
2) second reason
As per "ALLEE'S PRINCIPLE" Population Dynamics which stated due to competition for resources, a population will experience a reduced in overall Growth rate at Higher Density and increased growth at the lower density due to reverse holds or Negative regulation of population density.
3) Third reason
When population density is very low then the Interaction between two cell for the further metabolic activity or reproductive activity is also low or nill there for important molecules diffuse out due to leaky nature of the cell in surrounding area but bacterial cell due distance is very much ,cant utilize it and ultimately growth rate will decrese.
How "VITAMIN C" is important in INFECTION and LIGHTING of SKIN ?
As i read on NCBI, Vitamin C appears to be able to both prevent and treat respiratory and systemic infections. Vitamin C accumulates in phagocytic cells, such as neutrophils, and can enhance chemotaxis, phagocytosis, generation of reactive oxygen species, and ultimately microbial killing. It is also needed for apoptosis and clearance of the spent neutrophils from sites of infection by macrophages, thereby decreasing necrosis and potential tissue damage.
For skin, pleiotropic functions related to its ability to donate electrons. It is a potent antioxidant and a cofactor for a family of biosynthetic and gene regulatory enzymes. Vitamin C contributes to immune defense by supporting various cellular functions of both the innate and adaptive immune system. Vitamin C supports epithelial barrier function against pathogens and promotes the oxidant scavenging activity of the skin, thereby potentially protecting against environmental oxidative stress.
Quorum Sensing is the ability to detect and to respond to cell population density by gene regulation This process includes secreting the signaling molecules, e.g, c-AMP, other QS signaling molecules, concentration of signaling molecules , regulation of gene transcription.. If cell density is low then this signaling molecules must be diffuse away.. If cell density is high then local concentration may exceed its normal level and elicits the gene expression by feed back mechanism of regulation..
" DISCOVERY of NEW BACTERIAL SPECIES" "Staphylococcus cornubiensis"
discovered on a man in Cornwall. The bacteria was found on a 64 year old man seeking treatment for cellulitis. When researchers attempted to find the cause of this skin infection, they found the bacteria,
The discovery of S. cornubiensis was reported in the International Journal of Systematic and Evolutionary Microbiology along with evidence that this is a new species. After collecting S. cornubiensis from the skin infection, researchers at the University of Exeter Medical School and the Royal Cornwall Hospital found that it had not been reported before. They think it is part of a group of bacteria known as the Staphylococcus intermedius group (SIG). This is a group of harmful bacteria which are usually passed onto humans from pet dogs.
The SIG group of bacteria contains bacterial species Staphylococcus intermedius and Staphylococcus pseudointermedius, which have been identified as potential zoonotic threats, meaning there is a risk of these bacteria spreading to humans from animals and causing infection.
Elusive Asgard Archaea Finally Cultured in Lab 12 years of endevour reveals Prometheoarchaeum as a tentacled cell, living in a symbiotic relationship with methane-producing microbes... With the cultured microbe in hand, the researchers sequenced its full genome and confirmed the existence of eukaryote-like genes. They also observed that the microbe usually grows in tandem with a second, methane-producing archaeon, with whom it fosters a SYMBIOTIC RELATIONSHIP. Prometheoarchaeum breaks down amino acids and supplies its partner with energy in the form of hydrogen, which might otherwise impede the Asgard’s growth, according to Science.
Images captured with an electron microscope revealed that Prometheoarchaeum develops lengthy appendages with multiple branches, according to Nature. The microbe may have used the tentacles to grab hold of oxygen-producing organisms.
Streptococcus pneumoniae strains colonizing the Nasopharynx use Quorum Sensing and Fratricide to outcompete incoming strains, thereby retaining ownership of the host. This occurs via activation of the competence regulon, induction of lytic proteins, and turning the invader into a source of DNA for genetic exchange.
Resident pneumococci repel incoming competitors. S. pneumoniae colonizing a naïve host’s nasopharyngeal mucosa secretes the quorum-sensing peptide pheromone CSP. At a sufficient level of CSP, quorum signalling via ComDE induces genetic competence and the secretion of lytic proteins CbpD and CibAB. CbpD and CibAB can then lyse incoming pneumococci, which lack expression of cognate immunity factors. This may also provide donor DNA for uptake by the resident strain and extracellular DNA to promote biofilm formation.
there is some precedent for certain creatures being able to survive the vacuum of space. Tardigrades, water-dwelling microscopic invertebrates, are known to be able to survive a host of harsh environments. They can survive extreme temperatures (slightly above absolute zero to far above boiling), amounts of radiation hundreds of times higher than the lethal dose for a human, pressure around six times more than found in the deepest parts of the ocean, and the vacuum of space. The organisms found on the ISS( international space station) aren’t tardigrades, but the little invertebrates show that some living organisms from Earth can indeed survive the harshness of space.
scientists just Found a Completely New Kind of SYMBIOTIC RELATIONSHIP Between "SALAMANDER" AND "ALGA"
the green alga "Oophila amblystomatis" makes its home inside of cells located across the body of the spotted salamander "Ambystoma maculatum".
Back in the late 19th century, biologists learned that green algae grows in the egg cases of spotted salamanders, providing a win-win situation for both; the embryos produce nitrogen-rich waste for the algae, and in turn, the algae increases the oxygen content found in the fluid around the breathing embryos through photosynthesis. For well over a century, scientists had assumed that this mutually-beneficial arrangement only occurred between the salamander embryo and the algae living outside it.
But it is found in matured salamander and alga too. There are several possiblities for symbiotic relation ,
1) First relationship protects the salamander from pathogens. The salamanders allow the green algae to enter their tissues and cells, but the salamander’s immune response may actually block more harmful pathogens from doing the same. The arrangement could offer salamanders protection once they hatch into the more hostile environment of the pond. “This would be something like a ‘defensive symbiosis,’ which is only theoretical at this point,” said Burns.
2) second It’s also possible that the green algae—despite having to use fermentation to produce energy—is benefitting the salamander cells by producing nutrients, albeit fewer than they would normally produce under high oxygen conditions. “Also, though photosynthesis seems to be tuned down, it is still active and may be aiding the alga to use some energy from the sun through modified pathways,” said Burns. Which, if true, would be really cool—it means the amphibian is indirectly benefiting from photosynthesis in a manner similar to how coral does.
One of the reasons to use incubation period of 5 days for BOD determination is to eliminate oxygen demand for nitrification (Due to low growth rate of nitrifying bacteria. the nitrogenous BOD demand normally occurs from 6 to 10 days) and to find out only carbonaceous oxygen demand (BOD5/BODu = 0.68)
latest study on insect microbe symbiosis involves beewolf digger wasps(philanthus spp. Hymenoptera) in association with actinobacteria In this, the beewolf digger females carrying actinobacteria in unique antennal glands apply the symbionts to the brood cells prior to depostion,this defends the developing wasp larvae from pathogenic fungi and bacteria.Thus,leading to vastly improved odds of survival.
Sir once you asked us that why do the culture look turbid to us? The answer to this question is that the cell scatter light that falls on it. The turbidity is directly proportional to the number of cells. Higher the number of cells ,higher will be the scattering of light and higher amount of light reaches our eyes, hence it looks turbid to us.
hok system hok system is a post-segregational killing mechanism employed by R1 plasmid in e. coli. hok system involves 3 genes :1) hok :host killing 2) sok: suppression of killing 3)mok: modulation of killing. hok system genes codes for 52 amino acid toxic protein that causes death by depolarization of cell membrane. It works in similar way to holin protein that are provided by bacteriophage before cell lysis.
Preservation of microbial cultures. A surprising success has been reported (Boeswinkel, 1976 ; Marx and Daniel, 1976) for storage of fungus cultures in water. Steps involved in this simple method are as follows : 1)The fungus is grown on weak medium in petri plate and then cut into small pieces. 2) By using sterile technique the pieces are transfered to sterile distilled water in small screw capped bottles. 3) The cap is screwed down. 4)The cultures are stored, preferably at low temperature. Other methods also include : storage of spores in sand, drying cultures on filter paper and sealing tubes with paraffin wax.
Clay mineral (and humic substances) affects the activity, ecology and population of microorganisms in soil. Clays modify the physicochemical environment of the microbes which either enhance or attenuate the growth of individual microbial population.
After release from clays, the organic material is either degraded by microorganisms or again bind to clays. Microorganisms have a negative charge at the pH of most microbial habitats. The magnitude of electronegativity on cell walls of bacteria and fungi is regulated by pH, amino acid residues and changes in wall composition.
Effect of attachment of bacteria to chemostat walls in a microbial predator - prey relationship Mixed cultures of the protozoan Tetrahymena pyriformis and the bacterium Escherichia coli were propagated in chemostats fed with glucose and minimal mineral salts medium. The interior surfaces of some chemostats were treated with a silicone compound but those of other chemostats were not. Data obtained showed that bacteria but not protozoans were attached strongly to the walls of the chemostats, that silicone treatment reduced the density of the attached bacteria by two orders of magnitude or more, and that the presence of the attached bacteria had significant effects on the dynamics of the microbial predator-prey system. Attempts were made to simulate the data by various mathematical models. It was found that a model based on combination of the Topiwala-Hamer model for wall attachment and a multiple saturation model for growth of the protozoans on the bacteria gave a reasonable fit of all data.
Resource ratio theory: The R* rule (also called the resource-ratio hypothesis) is a hypothesis in community ecology that attempts to predict which species will become dominant as the result of competition for resources.The hypothesis was formulated by American ecologist David Tilman.It predicts that if multiple species are competing for a single limiting resource, then whichever species can survive at the lowest equilibrium resource level (i.e., the R*) can outcompete all other species.If two species are competing for two resources, then coexistence is only possible if each species has a lower R* on one of the resource
Psychrophiles are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from −20 °C to +10 °C. They are found in places that are permanently cold, such as the polar regions and the deep sea. They can be contrasted with thermophiles, which are organisms that thrive at unusually high temperatures.
Amensalism is any biological interaction between organisms of different species in which one organism is inhibited to grow or destroyed while the other organism remains unaffected.
Antibiosis is a type of amensalism. In antibiosis, one organism secretes a chemical that kills the other organism, while the one that secreted the chemical is unharmed. Example of antibiosis: Penicillium secretes penicillin which kills bacteria. the bread mold Penicillium and black walnut trees. You probably do not like to think about it, but many types of bacteria and fungi are perfectly capable of growing on bread under the right conditions. The bread mold Penicillium commonly grows on any bread that has passed its shelf life. This mold is capable of producing penicillin, which destroys many of the forms of bacteria that would also like to grow on this bread. It is the understanding of the bacteria killing properties of penicillin that led to the use of it as an antibiotic medicine. The penicillium does not benefit from the death of the other bacteria, making this an example of antibiosis.
Relation executing process of antagonism, Allelopathy. Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the germination, growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial (positive allelopathy) or detrimental (negative allelopathy) effects on the target organisms and the community. Allelochemicals are a subset of secondary metabolites,which are not required for metabolism (i.e. growth, development and reproduction) of the allelopathic organism. Allelochemicals with negative allelopathic effects are an important part of plant defense against herbivory. The production of allelochemicals are affected by biotic factors such as nutrients available, and abiotic factors such as temperature and pH. Allelopathy is characteristic of certain plants, algae, bacteria, coral, and fungi. Allelopathic interactions are an important factor in determining species distribution and abundance within plant communities, and are also thought to be important in the success of many invasive plants.
Some species may produce more than one allelochemical; for example, three different phyotoxins, geldanamycin, nigericin, and hydanthocidin, were isolated from Streptomyces hygroscopicus. Efforts to introduce naturally produced allelochemicals as plant growth-regulating agents in agriculture have yielded two commercial herbicides, phosphinothricin, a product of Streptomyces viridochromogenes, and bialaphos from S. hygroscopicus.
What are Bacteriocins? Bacteriocins are proteinaceous or peptidic toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strais. They are similar to yeast and paramecium killing factors, and are structurally, functionally, and ecologically diverse.
Phytoplankton-zooplankton: phytoplankton are photosynthetic organisms, including algae, blue-green algae or cyanobacteria while Zooplankton include protozoans such as foraminiferans, radiolarians, and non-photosynthesizing dinoflagellates as well as animals like tiny fish and crustaceans such as krill.
As phytoplankton are plants, they obtain their energy through the conversion of sunlight in photosynthesis and pull nutrients from the water around them. Zooplankton generally feed upon other plankton, including phytoplankton and zooplankton, along with bacteria and various types of particulate plant matter. So, Phytoplankton are the primary food source for the zooplankton. But, In severe cases, the massive overgrowth of the phytoplankton such as algae can release sufficient toxins to cause a die-off of fish and marine animals in the area, creating what is known as a dead zone in the water. That known as harmful algae blooms.
Amensalism is the phenomenon where one microbial species is adversely affected by the other species, whereas the other species is unaffected by the first one. Generally, amensalism is accomplished by secretion of inhibitory substances such as antibiotics, etc. Antibiosis is a situation where the metabolites secreted by organism A inhibits the organism B, but the organism A is unaffected . Metabolites penetrate the cell wall and inhibit its activity by chemical toxicity. Generally, antimicrobial metabolites produced by microorganisms are antibiotics, siderophores, enzymes, etc. The potent antagonists e.g. Trichoderma harzianum and T. viride are known to secrete cell wall lysing enzymes, β-1, 3-glucanase, chitinase, etc. Lysis of fungal mycelium occurs due to secretion of enzymes.
Microbe - Animal interaction: Endosymbiosis of Bacteria and Fungi with Birds and Insects: Moreover, there is a group of birds belonging to the genus Indicator which are commonly known as honey guides. These birds are found in Africa and also in India. These birds eat upon remnants of exposed honey comb but cannot digest bees wax. Therefore, they harbour in their intestine the two microbes. Micrococcus cerolyticus and Candida albicans for carrying out the digestion of bees wax. Except carnivorous insects, the others that live upon blood or plant sap develop symbiotic association with bacteria such as coryneforms and Gram-negative rods, and Nocardia (a member of actinomycetes). These microsymbiont are present in insect hosts in specialised cells. The cells that contain fungi are called mycetocytes, and those that contain bacteria are called bacteriocytes. These microsymbionts provide to the insects with some growth factors (that are lacking in insects) and some essential amino acids. Also the microsymbionts assist in breakdown of certain waste products
What is chromatophore? Chromatophore is a coloured, membrane-associated vesicle used to perform photosynthesis and contain different coloured pigments. Chromatophores contain bacteriochlorophyll pigments and carotenoids. In purple bacteria, such as Rhodospirillum rubrum, the light-harvesting proteins are intrinsic to the chromatophore membranes. However, in green sulfur bacteria, they are arranged in specialised antenna complexes called chlorosomes. Chromatophores are responsible for absorption of light in bacteria.
What are biofilm? Biofilms are a collection of one or more types of microorganisms that can grow on many different surfaces. Microorganisms that form biofilms include bacteria, fungi and protists. One common example of a biofilm is dental plaque, a slimy buildup of bacteria that forms on the surfaces of teeth. Pond scum is another example. Biofilms have been found growing on minerals and metals. They have been found underwater, underground and above the ground. They can grow on plant tissues and animal tissues, and on implanted medical devices such as catheters and pacemakers. It can be said that, for surviving bacteria uses this (biofilm) stratergy.
Sir, once in class you asked what is chromogenic media? Chromogenic Media are culture medium used to isolate, identify, and differentiate specific microorganism from a heterogeneous population. The medium contains chromogenic substrate which is utilized by the microorganism to give colored colonies that is specific for each microorganism. Depending on the color of the result, the presence or absence of target organism is determined and also accurately differentiated from others.
Principle of Chromogenic media are based on enzymatic utilization of chromogenic substrates. Principle of Chromogenic Media: Chromogenic media contains soluble colorless molecules called chromogens. Chromogens are composed of two parts: a substrate ( which is the target of a specific enzymatic activity of the microorganism) and a chromophore. When the bond between the substrate and chromophore is split by a specific enzyme produced by the target microorganism, chromophore is released. In its unconjugated form, the chromophore shows distinctive colour. Due to reduced solubility, chromophore forms a precipitate that imparts unique color to the colony.
What parameters will we change for a violet color bacteria in the growth kinetics experiment? In an actual sense, there won't be any change needed in the setting up of parameters in the experiment, as the coloured bacteria will have the same growth kinetics like an uncoloured bacteria. The violet bacteria will have the lag phase, log (exponential) phase, stationary phase and decline phase, just as any normal bacteria will have. The only adjustment that will be need in such cases is the change in the wavelength depending upon the colour. The violet bacteria will not absorb violet hence that is transmitted making it look violet. Hence the violet bacteria will absorb in the wavelength that is complementary to it. The complementary colour to violet is yellow, hence it will absorb in the yellow colour wavelength that is 570nm. So the only thing that will change will be the wavelength for taking the Optical Density which will be 570nm instead of 625nm.
Psychrophiles and Psychotrophs. Psychrophiles are organisms that are capable of growth and reproduction in low temperatures, ranging from −20 °C to +10 °C. They are found in places that are permanently cold, such as the polar regions and the deep sea, icebergs, etc. They need cold temperatures to survive. Without such low temperatures they cannot exist or will die. Psychrotrophs are cold-tolerant bacteria that have the ability to grow at low temperatures, but have optimal growth temperatures above 15 and 20°C. These bacteria can grow in cold temperatures but do not need cold temperatures to exist. They can grow in a range of temperatures and can also be Mesophilic in nature.
What happens if all microbes were removed from the earth? Louis Pasteur once said ,"Life would not long remain possible in the absence of micobes." Microorganisms are the oldest inhabitants of the Earth. They have been here since 3.6 billion years ago. If there were no microbes, there would have not been any evolution and hence no variations and no different types of life forms on Earth. What if in present time there were no microorganisms present: 1] The level of oxygen in the atmosphere would get depleted. As, phyto-planktons produce 50% of oxygen in the atmosphere. 2] The decomposition of the dead plants,animals and other matters will not be possible. 3] The plants would not be able to perform photosynthesis which will cause a imbalance the environment. 4] The human gut bacteria will not exist hence the essential vitamins produced by such bacteria, needed by the human will not be present. Hence that will lead to severe deficiencies. 5] The world population will increase to a point that the earth will be out of the resources and soon it will be inhabitable, due to depletion of all the natural resources because of increasing demand of food. Soon humans would perish so will the other living organisms. Hence it is impossible to imagine a life without microorganisms.
What will happen if all microbes are removed from the earth?
1)Naturally all infectious diseases would vanish. No Ebola,No common colds,No yeast infections,etc. This may seem like the best thing ever to happen to humans, but eventually , the loss of microbes would have direct consequences for humans, animals, plants, and the environment .
2)Most nutrients would stop being made or cycled Life depends upon the constant cycling and recycling of the basic elements of life. For example,plants survives via photosynthesis on water (hydrogen and oxygen), sunlight (to convert water and carbon dioxide into sugar), and a host of other elements like nitrogen, phosphorous, and potassium. All of these basic chemicals are taken in from the environment and recycled back to the Earth after they're consumed. As Bacteria, for example, convert nitrogen and carbon dioxide from the air into usable components that plants and animals can use as essential building blocks. A loss of all microbes would be terrible news for living organisms as we can't create or take in these essential nutrients on our own.
3)Waste would accumulate. If there aren't any microbes to break down complex compounds into their usable components, all of the unhealthy things is going to build up. Human and animal waste, for instance, is normally taken up by bacteria and cycled back into the environment.All plants would die. As we've learned, plants are reliant upon bacteria to survive.If they don't have microbes to take in and convert important chemical compounds into usable parts, they'll rapidly lose to ability to produce fuel via photosynthesis and will quickly die.
4)All ruminant animals — like cows, sheep, and goats would starve.Ruminant animals can't digest cellulose, the main compound that makes up plant cell walls, on their own. They rely on gut microbes that can break down cellulose, allowing the animal to digest and absorb the nutrients from the plant. A loss of microbes would mean that they'd starve And this assumes that there are plants to eat in the first place. Again, a loss of microbes entirely would mean that there would be no plants for them to eat at all.
Humans and other life would survive in the short term, but eventually would die. In the end, we could survive for a period of time without microbes, but not our whole life.
Sir , once you asked, Why decline phase has decreased O. D value? The answe to this question is , In death phase, number of dead cells are more than number of live cells, These dead cell undergo cell lysis and then cells contents precipitate and do not continue suspended as cell suspension and OD measure basically absorbance of suspended cell, this in turn decrease OD
Why most of microorganisms resides in large intestine ? Answer to this question is , many bacteria that inhabit the large intestine can further digest some material, creating gas. Bacteria in the large intestine also make some important substances, such as vitamin K, which plays an important role in blood clotting. These bacteria are necessary for healthy intestinal function.
Rumen fermentation is a process that converts ingested feed into energy sources for the host. Fiber scratches the rumen wall to start a series of contractions. These contractions lead to rumination, which is the process that physically breaks down the fiber source. Feed is then regurgitated, chewed and swallowed usually 50 to 70 times during rumination before passing through the next compartment of the stomach.
Microbial populations ferment feed and water into volatile fatty acids and gases (methane and carbon dioxide). When fermentable carbohydrate in the diet is digested too rapidly, the bacteria will increase the production of both volatile fatty acids and lactic acid. To sustain growth and the activity of fibrolytic microbes, it is crucial to maintain ruminal pH above 5.8, which will prevent the decline of fiber digestion and subsequent problems.
What is Coevolution? Coevolution involves reciprocal adaptive changes that occur among interdependent species. Antagonistic relationships, mutualistic relationships, and commensalistic relationships in communities promote coevolution. Coevolutionary antagonistic interactions are observed in predator-prey and host-parasite relationships. Coevolutionary mutualistic interactions involve the development of mutually beneficial relationships between species. Coevolutionary commensalistic interactions include relationships where one species benefits while the other is not harmed. Batesian mimicry is one such example
QUESTION:What would happen if there were no microorganisms? If there were no microorganisms on the Earth then there would be no life as we understand it because evolution from a common microscopic ancestor could not have happened. As we all know that multicellular organisms evolved from unicellular organisms so if there were no unicellular organism than possibly there will be no existence of multicellular organism.
QUESTION:What would happen if microorganisms suddenly get disappear? If all microbes disappeared we'd get to enjoy life without microbial disease this sounds good and humans, oddly, would be fine. Unlike other animals,for whom sterility would mean a quick death we would get by for weeks, months, even years. now another part which is so bad. All photosynthesis would likely cease. Bacteria are vital in keeping nitrogen cycling through the ecosystem, and nitrogen is vital to plant growth. We'd need to come up with some artificial way of releasing nitrogen from dead organisms and redistributing it, or the planet would slowly starve. Along with other grazing mammals, our livestock would perish. Without bacteria around to break down biological waste, it would build up. And dead organisms wouldn't return their nutrients back to the system. phytoplankton,responsible for producing an estimated 80% of the world's oxygen, so there will be less oxygen to breath. Annihilation of most humans and non microscopic life on the planet would follow a prolonged period of starvation, disease,and global biogeochemical asphyxiation.
QUESTION:Symbiotic association found in 2019? Beetles (Coleoptera) have the highest species diversity among all orders, and they have diverse food habits. Gut microbes may have contributed to this diversification of food habits. Scientists identified the pattern of the relationship between ground-dwelling beetles and their gut microbial communities (bacteria and fungi) in the field. Scientists collected 46 beetle species of five families from secondary deciduous forests and grasslands in Japan and extracted microbial DNA from whole guts for amplicon sequencing. The gut bacterial and fungal communities differed among all habitats and all food habits of their hosts (carnivores, herbivores, omnivores, and scavengers) except for the fungal communities between carnivores and scavengers. Specifically, the abundant bacterial group varied among food habits: Xanthomonadaceae were abundant in scavengers, whereas Enterobacteriaceae were abundant in carnivores and herbivores. Phylogenetically closely related beetles had phylogenetically similar communities of Enterobacteriaceae, suggesting that the community structure of this family is related to the evolutionary change in beetle ecology. One of the fungal groups, Yarrowia species, which has been reported to have a symbiotic relationship with silphid beetles, was also detected from various carnivorous beetles.
Ectosymbiotic bacteria at the origin of magnetoreception in a marine protist:
Mutualistic symbioses are often a source of evolutionary innovation and drivers of biological diversification. They are widely distributed in the microbial world, particularly in anoxic settings, they often rely on metabolic exchanges and syntrophy. Here, it was reported that a mutualistic symbiosis observed in marine anoxic sediments between excavate protists (Symbiontida, Euglenozoa)and ectosymbiotic Deltaproteobacteria biomineralizing ferrimagnetic nanoparticles. Light and electron microscopy observations as well as genomic data support a multi-layered mutualism based on collective magnetotactic motility with division of labour and interspecies hydrogen-transfer-based syntrophy. The guided motility of the consortia along the geomagnetic field is allowed by the magnetic moment of the non-motile ectosymbiotic bacteria combined with the protist motor activity, which is a unique example of eukaryotic magnetoreception acquired by symbiosis. The nearly complete deltaproteobacterial genome assembled from a single consortium contains a full magnetosome gene set, but shows signs of reduction, with the probable loss of flagellar genes. Based on the metabolic gene content, the ectosymbiotic bacteria are anaerobic sulfate-reducing chemolithoautotrophs that likely reduce sulfate with hydrogen produced by hydrogenosome-like organelles underlying the plasma membrane of the protist. In addition to being necessary hydrogen sinks, ectosymbionts may provide organics to the protist by diffusion and predation, as shown by magnetosome-containing digestive vacuoles. Phylogenetic analyses of 16S and 18S ribosomal RNA genes from magnetotactic consortia in marine sediments across the Northern and Southern hemispheres indicate a host–ectosymbiont specificity and co-evolution. This suggests a historical acquisition of magnetoreception by a euglenozoan ancestor from Deltaproteobacteria followed by subsequent diversification. It also supports the cosmopolitan nature of this type of symbiosis in marine anoxic sediments.
Why is it important to study archaea? They contribute to global nutrient cycle. Help in understanding evolution better as they are at the root of phylogenetic tree. They are the major routes for ammonium oxidation. Also serve as novel commercial organisms, eg. Production of thermostable polymerases. Ammonia oxidizing archaea(AOA) - found abundant in oceans, soils and salt marshes. Only one AOA pure cultures could be made till today - that of Nitrosopumilus maritimus. AOA have greatly outnumber AOB(Ammonia Oxidizing Bacteria) in many common environments. Ether linked lipids from Archaea- possible adjuvants in antigen delivery but still not been used in commercial vaccine production. It is believed that archaea in mutualistic relationships may provide health benefits also.
Viruses of Archaea. 1.In hypersaline environments, haloarchaea (halophilic members of the Archaea) are the dominant organisms, and the viruses that infect them, haloarchaeoviruses are at least ten times more abundant. Since their discovery in 1974, described haloarchaeoviruses include head-tailed, pleomorphic, spherical and spindle-shaped morphologies, representing Myoviridae, Siphoviridae, Podoviridae, Pleolipoviridae, Sphaerolipoviridae and Fuselloviridae families. 2.new virus of hyperthermophilic archaea, Sulfolobus polyhedral virus 1 (SPV1), which condenses its circular double-stranded DNA genome in a manner not previously observed for other known viruses.
Why is it important to study archaea ..!!?? The most significant role that the procaryotes (eubacteria and archaea) play in the ecosystem is that they recycle the essential elements and regulate the bigeochemical processes. In mesophilic environment, a large group of archaea are ammonia oxidisers.. ... Archaea are also involved in anaerobic methane oxidation. So far, most archaea are known to be beneficial rather than harmful to human health. They may be important for reducing skin pH or keeping it at low levels, and lower pH is associated with lower susceptibility to infections.
What are the benefits to microbes living in biofilms? Biofilm is a strong and dynamic structure that confers a broad range of advantages to its members, such as adhesion/cohesion capabilities, mechanical properties, nutritional sources, metabolite exchange platform, cellular communication, protection and resistance to drugs (e.g., antimicrobials, antiseptics, and disinfectants), environmental stresses (e.g., dehydration and ultraviolet light), host immune attacks (e.g., antibodies, complement system, antimicrobial peptides, and phagocytes), and shear forces.
What would have happen if the Microorganism suddenly disappear ? The answer to this can have merits and demerits first going with the merits if the microorganism disappears than there will be no human and microbe interaction which will decrease the mortality rate and no person will die out of disease except autoimmune diseases . There be will no contamination of things kept open 3. No use of medicines and antibiotics. Now coming into to Demerits 1. As population rate will increase due to no death 2. Fossils wont be available 3. Economy will get affected due to no fermentation industry and dairy industry will come to an end . Drugs manufacturing companies will perhaps be at the verge 4. The helpful microbes present inside the body wont be there so metabolism will be affected...
What's the ecological role of phyto planktons? Phytoplankton are major primary producers in the aquatic realm, responsible for almost half of global net primary production (Field et al. 1998). Their abundance and community structure directly impact higher trophic levels and key biogeochemical cycles. Phytoplankton are an extremely diverse, polyphyletic group that includes both prokaryotic and eukaryotic forms. What makes phytoplankton so successful? Several fundamental processes, such as photosynthesis, growth, resource acquisition, and grazer avoidance, to a large degree define ecological niche of phytoplankton. The success of phytoplankton depends on how efficiently they acquire resources, transform them into growth, and avoid being eaten or infected. Diverse selective pressures on phytoplankton increase the efficiency of these processes and allow species to persist under changing conditions. Resource competition is one of the key ecological processes that controls species composition, diversity, and succession of phytoplankton communities. In this chapter I discuss the role of resource competition in structuring past, present, and future phytoplankton communities.
QUESTION:Why is it important to study archaea? Studies of archaea have proven to be enormously fruitful: unique traits found nowhere else in nature have been revealed in archaea, and there are many instances of archaeal processes that combine a mosaic of bacterial and eukaryal features with unique archaeal ones to create a third functioning mechanism. Archaea are useful model systems for processes in both eukarya and bacteria, and their major roles in various ecosystems, not just extremophilic ones, continue to be uncovered. They have useful biotechnology/ commercial applications, and may yet prove to affect human health in significant ways. There is continued study and debate about their role in evolution and, due to their ability to thrive at the limits of life on Earth, the possible presence of organisms that resemble the archaea in extraterrestrial environments. Archaea have some unique feature like Ether-linked lipids, Unique cell envelopes, Novel surface appendages, New virus families, ssrRNA signatures, tRNA modifications, Ribosome structure, Ribosome composition, Antibiotic sensitivity pattern, RNA polymerase composition, Growth above 100 degree Celsius, Methanogenesis and unique coenzymes, Sulfur-oxidizing pathways, Hyperthermophilic nitrogen fixation, Ammonia oxidation mechanism, Lipoylation, Modified sugar-degrading pathways.
what is reverse electron flow and why it is necessary? Fe+3, SO32-, NO31-etc are chemolithotrophs bacteria. they have a redox potential too positive to reduce NAD+. In reverse electron flow Delta mu H+ (transmembrane electrochemical proton potential ) is used to drive the transfer of electron from an electron donor with more positive redox potential to an acceptor with more negative redox potential. In other words,Delta mu H+ is driving force for this process. reverse electron flow has to occure whenever the redox potential of the electron donor too positive to reduce NAD+ to NADH. the energy consumed in reverse electron transport is five times greater than energy gained from the forward process.
Question: how to cultivate extremophiles: there are some specialized bioreactors which are made which has high temperature and greatly elevated. pressure.https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.clarklab.org/research/extremophiles&ved=2ahUKEwjZt8XPrY7lAhXDpY8KHZ1pB4YQFjARegQICBAB&usg=AOvVaw2LsNPRVOmiQCK9s7En0ZLi&cshid=1570596601543 Given link has a brief content to cultivation of extremophiles and the picture of the specialized bioreactor in which cultivation occurs. 19mbt042 malhar thakar
Key difference between archae and bacteria : 1) Like the bacteria, archaea are single-cell, simple prokaryotes, lacking the well-defined nucleus and other organelles. Archaea are capable of surviving under the extreme condition and so are considered as extremophiles. 2)Archaea are found in the unusual environment like in hot spring, ocean depth, salt brines, while bacteria are found everywhere like in the soil, water, living and non-living organisms. 3)The cell wall of archaea is pseudopeptidoglycan, as they have ether bonds with the branching of aliphatic acids, whereas bacteria have lipid membrane ester bonds with fatty acids. 4)Archaea exactly do not follow glycolysis or Kreb cycle but uses similar pathway, but bacteria follows these pathways to produce energy. 5)Methanogens, Halophiles, Thermoacidophiles are the type of archaea, while gram positive and gram negative are the types of bacteria. 6)Archaea reproduce asexually by binary fission, fragmentation, or by the budding process, on the other hand, bacteria can produce spores which allow them to live in unfavourable condition and they divide sexually as well as asexually. 7)In archaea features like thymine is absent in the tRNA (transferase RNA) and introns are present, whereas in bacteria thymine is present in the tRNA and introns are absent. 8)In archaea, the RNA polymerase is complex and contains ten subunits, while in RNA polymerase in bacteria is simple and contains four subunits. 9)Pyrolobus fumarii, Sulfolobus acidocaldarius, Pyrococcus furiosus, Methanobacterium formicum are few examples of archaea. Streptococcus pneumoniae, Yersinia pestis, Escherichia coli (E.coli), Salmonella enterica, are the examples of bacteria.
Cultivation of extremophiles: There are exploitation of microorganisms isolated from extreme environments, e.g., deep-sea hydrothermal vents. These versatile organisms, so-called extremophiles, are able to grow and survive in harsh environments and should thus be useful under a broad range of process conditions. Many believe such organisms are also the progenitors of all other organisms and may thus hold clues into the origins of life. For this research, specialized apparatus were constructed that can duplicate the most extreme conditions on Earth known to support life, i.e., high temperatures and greatly elevated pressures. By studying extremophiles under these conditions, it was able to examine mechanisms by which these robust organisms adapt to stressful extremes and explore new bioprocesses at the outer limits of life.
QUESTION:Why visible photometry is a useful method for bacterial growth quantification despite non pigmented bacterial cells not absorbing much in visible spectrum? OD is not mere an absorption. Cells of many bacteria are colourless and light absorption by them is marginal. Strongly pigmented cells such as phototropic bacteria significantly absorb light in addition to scattering. The principle of photometric analysis is scattering which is only observed in non pigmented cells.
QUESTION :Why is it important to study archaea? ANSWER :unique traits found nowhere else in nature have been revealed in archaea, and there are many instances of archaeal processes that combine a mosaic of bacterial and eukaryal features with unique archaeal ones to create a third functioning mechanism. - Archaea are useful model systems for processes in both eukarya and bacteria, and their major roles in various ecosystems, not just extremophilic ones, continue to be uncovered. -They have also useful for commercial applications, and may yet prove to affect human health in significant ways. There is continued study and debate about their role in evolution and, due to their ability to thrive at the limits of life on Earth, the possible presence of organisms that resemble the archaea in extraterrestrial environments. so,the study of archaea is very important because of it's unique features and environmental importance.
Question:Why different microorganisms have different shape? Answer:Different shapes of microorganisms is an adaptation to have access to nutrition,motility, escaping predators and to fit to the particular environment.Moreover it would have been difficult for us to primarily identify them under microscope.
QUESTION:What would happen if microorganisms suddenly get disappear? There are pros and cons of every situation. World without microorganisms would be happy, free from all infections and diseases which may also result into population burst! We would be free from the fear of spoilage of fruits and vegetables, milk, meat, eggs etc. On the other hand,global photosynthesis would come to halt, Nitrogen fixation would cease and plants would not obtain balanced nutrition. Decomposition of organic matter into simpler substances and recycling of natural waste would be almost be impossible. Our body constitutes of 10 fold microbes than that of human cells which proves their usefulness to us in every way, in every process that is carried out in our body. They are responsible for development of immune system, digestion, production of Vitamin K , detoxification of harmful chemicals in our body. No fermentation , no sewage treatment, no production of fuels, enzymes and bioactive compounds and in almost all the fields they are useful. These earliest forms of life are omnipresent without which survival of multicellular organisms would be difficult. Best example is of Deinococcus radiodurans - world's toughest bacterium in 'The Guinness book of world records'. It is most radiation resistant organism surviving in thousand times more radiations than a human can and all other extreme conditions so they are also called as polyextremophile. These are also very useful for biomedical research, nanotechnology and bioremediation.
Why cells are different in shape? Ans: Cells have different shapes because they do different things. Each cell type has its own role to play in helping bodies to work properly, and shapes help them carry out these roles effectively. If all the cells will be of same shape and size , it will be very difficult for multicellular animals including humans to adapt better to the environment and survive. For example Red blood cells, immune cells, Neuron cells.
Methanogens are responsible for the methane in the belches of ruminants and in the flatulence in humans. Methanogens play a vital ecological role in anaerobic environments by removing excess hydrogen and fermentation products produced by other forms of anaerobic respiration.
>Pigmentation is very useful for organism. >It is associated with morphological characteristics, cellular activities, pathogenesis, protection and survival. >Pigmentation help to carry out photosynthesis. Eg. Autotrophic cyanobacteria contain chlorophyll (green pigment) > Pigmentation help to absorb UV radiation or to quench oxygen free radicals (i.e. basically help in cell protection) > Pigmentation helps to maintain membrane integrity and stability. > Pigmentation may act as antibiotics against phytopathogenic funi, bacteria and yeast Eg. Spirilloxanthin from spirillum Prodigiosis from serratia > Pigmentation help in survival in stress conditions Eg. Pigment produce by pseudomonas sp. Like pyoverdin and pyochelin act as siderosphor. (i.e. scavenge trace of iron.) In Rhizosphere region, iron is present in limited amount. Rhizobacteria like pseudomonad produce iron chelating compound or siderosphor (i.e. scavenge trace of iron.)
19MBT019 Pigmentation is also used for microbe microbe interactions and communication for example Pyocyanin a blue pigment that is a toxin produced and secreted by the Gram negative bacterium Pseudomonas aeruginosa. Pyocyanin is a secondary metabolite with the ability to oxidise and reduce other molecules and therefore can kill microbes competing against P. aeruginosa.
The shape of bacteria is defined mainly according to the environment they live in or the problems they are facing in their habitat. For this we can give two types of arguments: 1. The shape of bacteria is same for any one genus which typically exhibits a limited subset of morphologies, hinting that, with a universe of shapes to choose from, individual bacteria adapt only those that are adaptive. 2. Some can modify their morphology in response to environmental cues or during the course of pathogenesis suggesting that shape is important enough to merit regulation. Thus, from this arguments we can say that the shape of bacteria is defined by the parameters around them like availability of nutrition, motility of cell, predation activity around them, etc.
What is coevolution ..?? the influence of closely associated species on each other in their evolution. coevolution refers to the evolution of at least two species, which occurs in a mutually dependent manner. ... An example is the coevolution of flowering plants and associated pollinators .e.g., bees, birds, and other insect species.
What happens if all microbes were removed from the earth? Microbes play a central part in most of all eco systems Microbes help in the recycles the nutrients by degrading dead plant and animals Micro plants called phytoplanktons present in ocean produce around 50% oxygen apart from plant it also affect the animals and plants , in our body there are trillions of bacteria they helps in digestion of food and also affect the behaviour of individuals
QUESTION:Purpose of pigment production in bacteria? Different bacteria can produce different colour pigments which show taxonomical significance - Pigments important for particular genus - helpful in identification and classification. Mainly bacteria produce pigments as secondary metabolites. Colour of the pigments is their secondary property while their primary properties are :- Photosynthesis - autotrophic bacteria need pigments for photosynthesis. Cell protection - Pigments produced by bacteria absorb UV radiations or form products from oxygen free radicals.Defence mechanism - pigments can also protect bacteria from virulence and protect extremophiles from oxidative stress. Multidrug resistance and heavy metal resistance - Pathogenic staphylococci are multi drug resistant because their pigments act as a barrier for antibodies acting on cell wall and plasma membrane.
Role of pigment production in bacteria : Pigments are compounds with characteristics of importance to many industries. Among microbes, bacteria have immense potential to produce diverse bioproducts and one such bioproduct is pigments. There are many reason the bacteria to produce pigments.
1. Phototsynthesis 2. UV protection 3. Defense mechanisms 4.Secondary metabolites for storage of energy 5. Stress
It varies with environment differs in marine, terrestrial and space.
Q-what is the purpose of pigment production in bacteria? A-Pigments have evolved in nature to serve a variety of purpose. Pigments can serve a more fundamental purpose that includes protection from oxidative stress, absorption of light in plants and retina in animals, protection from harmfull UV light. It also play an important role in pathogenic microorganisms as pathogenecity inducer. If we remove gene which responsible for pigment production than they became harmless Eg:- Staphylococcus aureus It produce golden yellow pigment when pathogenic after gene removal they show nonpigmented colonies. Some species of microbes produce pigments against environmental stress. Eg:- Synechococcus species accumulate carotenoids in response to iron stress. Some compound induce the color pigmentation. Methanol induce color pigmentation in Acinetobacter wofii. Some pigments create harmfull effect on other cell. Eg:- vibrio cholera makes melanin which help to cause infection in GI track of human and survive in aquatic environments. Pigments are secondary metabolites so it energy require process. Some of them show toxic effect on other living form of life.
Q-why do all bacteria have different shapes? The different shapes of bacteria is based on the morphology of bacterial cell is affected by a combination of selective pressure, access to nutrients, cell division, attachment, dispersal, predation, motility and defence mechanism. Apart from that three factore may help to explain this secret of nature. 1)Nutrient uptake :- different shapes of cell is depend on the condition where nutrient available which may create condition that favour one bacterial shapes over another. 2)Motility:- motility imposes a heavy selective pressure on cell shape. It helps to travel from one place to another when condition became unfavourable. 3)predation:-it helps to protect itself when predator come and it helps to struggle against being eaten.
Q-why it is important to study archea? A- Archea looks like bacteria but biochemically and genetically they distinct from bacteria and they even closer to eukaryotic counter parts rather than prokaryotic. The metabolic pathway and enzymes which are involved they are more resemble to eukaryotic living system. The habitat from which they are identified and isolated it helps to study the living form of life on earth at early stage of evolution and also survival of life in extreme condition. Some archea have the genes which are not resemble to anyother living form. Eg:- archea which survive in extreme saline condition and some molecules of archea which survive in high acidic condition.
Question:-How halophiles protect them from osmotic shock? Answer:-Most halophilic and all halotolerant organisms expend energy to exclude salt from their cytoplasm to avoid protein aggregation known as salting out.To survive the high salinity, halophiles employ two differing strategies to prevent desiccation through osmotic movement of water out of their cytoplasm. Both strategies work by increasing the internal osmolarity of the cell.
Why bacteria have different shapes? 3 main points which defines the shape of Bacteria: Nutrient uptake: Cell shape, in and of itself, affects nutrient acquisition and argues that other nutritional situations may create conditions that favor one bacterial shape over another.
Motility: Motility imposes a heavy selective pressure on cell shape. Fast cells are better off as rods with a certain length-to-width ratio, chemotactic cells must adopt shape ratios in line with their environments, and cells that forage near surfaces or navigate viscous environments may do best if they are slightly curved or spiral.
Predation: In their struggle against being eaten, bacteria have adopted morphological defenses that may have produced the shapes These factors play a role in shaping bacteria. Bacterial morphology is affected by a combination of selective pressures - access to nutrients, cell division, attachment/dispersal, predation and motility (among others). Among these different factors, our understanding of the relationship between motility and cell shape is most complete; for example, highly motile bacteria are usually rods with a specific (optimal) shape and size, and movement through viscous fluids seems to a favor spiral shape. But since multiple selective forces are always in play, there is at the moment no way to predict cell shape based on the environment or vice versa. Adaptations to various environments could be possible but depending upon the environment we can not predict the shape of bacteria because some other factor might have played major role in giving shape to it.
Question:Which virus is infects the banana? Answer. : Banana bunchy top virus is infect the banana. this virus is from Nanoviridae family.The genome of BBTV is made up of at least six circular, single-stranded DNA components, each about 1 kilo-base pair in length.Replication takes place by rolling circle replication, a unidirectional nucleic acid replication that can result in rapid synthesis of single-strands of DNA.Like many viruses, BBTV was named after the symptoms seen, where the infected plants are stunted and have "bunchy" leaves at the top.
Infected banana plants by BBTV are stunted and produce small, deformed fruits. In advanced stages of the disease, plants do not produce any fruit. Infected banana plants are useless and serve only as a source of the virus. A tiny insect called the banana aphid spreads the disease by carrying the virus to healthy plants after feeding on infected plants.
Question:Which virus is infects the honey bees? Answer : According to NCBI Deformed wing virus (DWV) is infects the honey bee.DWV is a single-stranded RNA virus of honey bees. transmitted by the parasitic mite Varroa destructor. Although DWV represents a major threat to honey bee health worldwide, the pathological basis of DWV infection is not well documented.
Que:- What are virusoids?? Ans:- Virusoids belong to a large, group of infectious agents called satellite RNAs. They are found in bacteria, plants, fungi, invertebrates and vertebrates. They are satellite, viroid like molecules but larger than viroids. Satellite viruses encode capsid proteins but depend on a helper virus for replication, therefore, they are called ‘satellite’.
Q:-Which virus infect the honey bees? A:-DMV- Deformed Wing Virus DMV cause infection in honey bee(Apis mellifera). It leads major cause of elevated looses of honey bea colonies. It is SS-RNA virus. It has two widespread genotypes A and b. In adult honey bee DMV-B has been shown to be more virulent than DMV-A. The characteristics are not completely known for DMV.
Q:- Which virus cause infection in banana? A:-BBTV-Banana Bunchy Top Virus. It is SS-DNA virus. The virus is transmitted inapersistent circulative,non-propagative manner by the banana aphid Pentalunia nigronervosa which has worldwide distribution. It leads 70-90% loss of production in infected plant and that could not be recovered. Domain - Virus Group -SS-DNA viruses Sub group -DNA viruses Family - Nanoviridae Genus -Babuvirus Species -Banana Bunchy Top Virus .
banana is one of the most important staple food crops plants which grow, mature and fruit without seasonality throughout the year. Viral diseases are considered a major concern for banana production because of their effects on yield and quality as well as limitations to germplasm multiplication and the international germplasm exchange. There are many (about 20) different viruses reported to infect banana worldwide. However, the economically most important viruses are: Banana bunchy top virus (BBTV), Banana streak viruses (BSV), Banana bract mosaic virus (BBrMV) and Cucumber mosaic virus (CMV). Among these, BBTV and BSV are major threats for banana production. Of the two, BSV exist as episomal and endogenous forms and more widely spread worldwide than BBTV
Question:-How calcivirus cause infection in humans and animals? Answer:-Caliciviral infections in humans, among the most common causes of viral-induced vomiting and diarrhea, are caused by the Norwalk group of small round structured viruses, the Sapporo caliciviruses, and the hepatitis E agent. Human caliciviruses have been resistant to in vitro cultivation, and direct study of their origins and reservoirs outside infected humans or water and foods such as shellfish contaminated with human sewage has been difficult. Modes of transmission, other than direct fecal-oral routes, are not well understood. In contrast, animal viruses found in ocean reservoirs, which make up a second calicivirus group, can be cultivated in vitro. These viruses can emerge and infect terrestrial hosts, including humans.The history of animal caliciviruses,their eventual recognition as zoonotic agents, and their potential usefulness as a predictive model for non-cultivatable human and other animal caliciviruses.
Question:-Some discovery of virus? Answer:- Discovery of tobacco mosaic virus in 1892 and foot-and-mouth disease virus in 1898, the first 'filterable agent' to be discovered in humans was yellow fever virus in 1901
What are virusoids? virusoids are also infectious agents, but they differ from viruses in several ways. For instance, they have a single-stranded circular, RNA genome. Their genomes are very small and do not code for proteins. Viroids replicate autonomously inside a cell, but virusoids cannot. Rather, virusoid replication requires that the cell is also infected with a virus that supplies "helper" functions.
Parasitic mite Varroa destructor transmits ssRNA virus named Deformed wing virus(DMV) which infects honey bees (Apis Mellifera L.). DWV-affected bees were 2 times slower to emerge and had 30% higher mortality compared to clinically normal bees. DMV is a major threat to honey bees all over the world yet pathological basis of this infection is not well documented . Here is the reference:- https://www.ncbi.nlm.nih.gov/m/pubmed/30857499/
Four viral diseases that infects banana are banana bunchy top disease (BBTD) caused by Banana bunchy top virus (BBTV), bract mosaic disease (BBrMD) caused by Banana bract mosaic virus (BBrMV), banana streak disease (BSD) caused by different species of Banana streak virus (BSV), and banana mosaic or infectious chlorosis caused by Cucumber mosaic virus (CMV), occur in most of the banana-growing regions around the world. BBTD is a century-old disease resulting into large scale crop losses all over the world but its infectivity has not yet been proven through infectious clones. Banana bract mosaic virus (BBrMV) infects banana. The length and arrangements of different proteins in BBrMV-Cardamom was similar to other BBrMV isolates except for the P1 protein that showed a single amino acid deletion. Here are the references:- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5014477/ https://www.sciencedirect.com/topics/immunology-and-microbiology/banana-bunchy-top-virus
QUESTION:How many viruses known till date? The following list represents all ICTV taxonomy releases to date. There are 14 Orders, 150 Family, 79 Subfamily, 1019 Genus, 5560 Species of viruses have been classified till date.
Q- Why bacteria produce pigments? Pigments of various colors are synthesized to protect the cells of microorganisms from injurious effect of light rays of visible and near ultraviolet range. These pigments are synthesized by various types of microorganisms as secondary metabolites and not often found in all types of organisms. Pigments come in a wide variety of colors, some of which are water soluble. Micro-organisms which have the ability to produce pigments in high yields include species of Monascus, Paecilomyces, Serratia, Cordyceps, Streptomyces and yellow-red and blue compounds produced by Penicillium herquei and Penicillium atrovenetum, Rhodotorula, Sarcina, Cryptococcus, Monascus purpureus, Phaffia rhodozyma, Bacillus sp., Achromobacter, Yarrowia and Phaffia also produce a large number of pigment2 . Microorganisms produce various pigments like carotenoids, melanins, quinones, flavins, prodigiosins and more specifically monascins, violacein or indigo. Some pigments produced by the bacteria shows antimicrobial activity against pathogens.
Imagine the situation of Earth without microorganism. As correctly said by Louis Pasteur ,"Life would not long remain possible in the absence of micobes."
Microorganisms are the oldest inhabitants of the Earth. They have been here since 3.6 billion years ago. If there were no microbes, there would have not been any EVOLUTION and hence no VARIATIONS and no different types of life forms on Earth.
Talking about the present condition of Earth without microbes, survival of most Eukaryotes would be doubtful. 1) Germ free existence. 2) No biogeochemical cycling of nutrients. Rapid exhaustion of available macronutrients and micronutrients in terrestrial and aquatic environment. 3) Fungal decomposition would become the critical link between organisms death ,decay and return of decomposed nutrients to bottom of eukaryotic food chains. So most species on Earth would become extinct and population size would be reduced greatly for the species that endured. 4) we could digest our food as gnotobiotic animals, assimilating most of what we have consumed. 5) Imbalance in Ecosystem ,Food chain and Food web. 6) Absence of all forms of microbial disease including Ebola, Malaria, common cold, AIDS, and many more. 7) Human and animal waste would accumulate rapidly. There would be very little decomposition apart from dissociation and inherent catabolic enzymatic activity. It will lead to Soil and Water pollution. 8) Most ruminant livestock would starve without microbial symbionts. Plants would rapidly deplete Nitrogen, cease photosynthesis and then die. An alternative to it is to provide synthetic Nitrogen rich fertilizers. But it would lead to Global warming and pollution. Hence, concluding that Microbes sustain life on this planet because of myriad associations and biogeochemical processes. Although life would persist in the absence of microorganisms, both the quantity and quality of life would be reduced drastically.
Question:- Uses of viruses in different field? Answer:-1.Viruses in biological studies Viruses have been used extensively in molecular and cellular biology studies.Viruses have been used extensively in genetics research and understanding of the genes and DNA replication, transcription, RNA formation, translation, protein formation and basics of immunology. 2.Viruses in medicine Viruses are being used as vectors or carriers that take the required material for treatment of a disease to various target cells. They have been studied extensively in management of inherited diseases and genetic engineering as well as cancers. 3.Viruses in weapons and biological warfare Viruses may be tiny but have the capacity to cause death and devastation to large populations in epidemics and pandemics. This has led to the concern that viruses could be used for biological warfare. 4.Viruses and biological pest control Viruses can also be used to control damaging pests. Traditionally this has been used in agriculture, but applications exist in the control of agents important to human health as well.
Banana bunchy top virus(BBTV) is a plant pathogenic single stranded DNA virus of the family Nanoviridae. BBTV causes banana bunchy top disease in banana and causes the new leaves to be stunted & "bunchy" while leaf edges are deformed & yellow.
Acute Bee Paralysis Virus (ABPV) belongs to the family of Dicistroviridae. This virus causes sudden collapse of honey bee colonies infested with the parasitic mite Varroa destructor.
Difference between facultative aerobe and facultative anaerobe:
A facultative anaerobe is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation or anaerobic respiration if oxygen is absent. A faculitative aerobe like Lactobacillus ferment and therefore do not use oxygen, however they do tolerate it. Facultative aerobic bacteria do not require oxygen but can survive in presence of oxygen (generate ATP by aerobic respiration).
Martinus Beijerinck is considered one of the founders of virology. He independently performed Ivanowsky's filtration experiments and then showed that the infectious agent was able to reproduce and multiply in host cells of the tobacco plant. Beijerinck coined the term of "virus" to indicate that the casual agent of tobacco mosaic disease was of non bacterial nature.
SHRUTI SOLANKI (19MBT039) Q- How life can survive at unusual conditions? A- The extraordinary ability of microbial life to adapt to harsh conditions has increased the awareness of the potential value for the close study of such microorganisms. The unusual biomolecules they produce may be used as such, or modified structurally for many biological applications.
Q- What is the economical and environmental value of honeybees? A- The Honeybees offer a key ecosystem service, essential for a sustainable productive agriculture and for the maintenance of the non-agricultural ecosystem. Pollination services are mandatory for the production of crops like fruits, nuts and fibres, whereas the results of many other agricultural crops are significantly improved by pollination. A vast number of species were found to be honeybee-pollinated plants including, high bush blueberry; apple and pears; almonds; Cantaloupe; rape varieties; and others. Honeybees were found to have a key role in increasing the seed production of three crops: broccoli, kohlrabi and Chinese cabbage. Apis mellifera is of great economic importance in terms of increased yield and quality of commercially grown insect pollinated and also assists self-pollinated crops in the world. It has been valued that without pollinators a decrease by more than 90% of the yields of some fruit, seed and nut crops could occur.
What are virusoids? Virusoids are type of pathogenic RNA that can infect commercially important agricultural crops are the virusoids, which are subviral particles best described as non–self-replicating ssRNAs. RNA replication of virusoids is similar to that of viroids but, unlike viroids, virusoids require that the cell also be infected with a specific “helper” virus. There are currently only five described types of virusoids and their associated helper viruses. The helper viruses are all from the family of Sobemoviruses. An example of a helper virus is the subterranean clover mottle virus, which has an associated virusoid packaged inside the viral capsid. Once the helper virus enters the host cell, the virusoids are released and can be found free in plant cell cytoplasm, where they possess ribozyme activity. The helper virus undergoes typical viral replication independent of the activity of the virusoid. The virusoid genomes are small, only 220 to 388 nucleotides long. A virusoid genome does not code for any proteins, but instead serves only to replicate virusoid RNA. Virusoids belong to a larger group of infectious agents called satellite RNAs, which are similar pathogenic RNAs found in animals. Unlike the plant virusoids, satellite RNAs may encode for proteins; however, like plant virusoids, satellite RNAs must coinfect with a helper virus to replicate. One satellite RNA that infects humans and that has been described by some scientists as a virusoid is the hepatitis delta virus (HDV), which, by some reports, is also called hepatitis delta virusoid. Much larger than a plant virusoid, HDV has a circular, ssRNA genome of 1,700 nucleotides and can direct the biosynthesis of HDV-associated proteins. The HDV helper virus is the hepatitis B virus (HBV). Coinfection with HBV and HDV results in more severe pathological changes in the liver during infection, which is how HDV was first discovered.
Virus infecting banana: Banana bunchy top virus (BBTV) is responsible for infecting banana. Often BBTD, banana bunchy top disease, gets its name from the bunchy appearance of infected plants. By that time, however, the virus has most likely been spread to other plants by the banana aphid, Pentalonia nigronervosa. Infected plants cannot recover and will serve as a source of viral particles unless they are destroyed. The virus is also spread through infected planting material.
Discovery of virology: In 1892, Dmitry Ivanovsky used one of filters to show that sap from a diseased tobacco plant remained infectious to healthy tobacco plants despite having been filtered. Martinus Beijerinck called the filtered, infectious substance a "virus" and this discovery is considered to be the beginning of virology. Thus he , is the one who discovered viruses.
Viruses in biological studies: Viruses have been used extensively in molecular and cellular biology studies. These viruses provide the advantage of being simple systems that can be used to manipulate and investigate the functions of cells.
Viruses have been used extensively in genetics research and understanding of the genes and DNA replication, transcription, RNA formation, translation, protein formation and basics of immunology.
Viruses in medicine: Viruses are being used as vectors or carriers that take the required material for treatment of a disease to various target cells. They have been studied extensively in management of inherited diseases and genetic engineering as well as cancers.
Viruses in bacteriophage therapy: These are highly specific viruses that can target, infect, and (if correctly selected) destroy pathogenic bacteria. Bacteriophages are believed to be the most numerous type of viruses accounting for the majority of the viruses present on Earth. These are basic tools in molecular biology. They have been researched for their use in therapy.
Viruses in nanotechnology: Nanotechnology deals with microscopic particles. These have various uses in biology and medicine and nanotechnology has been used in genetic engineering. Viruses can be used as carriers for genetically modified sequences of genomes to the host cells.
Viruses in weapons and biological warfare: Viruses may be tiny but have the capacity to cause death and devastation to large populations in epidemics and pandemics. This has led to the concern that viruses could be used for biological warfare.
***Viruses that infect banana*** Banana bunchy top disease is the most serious virus disease of banana worldwide. Diseased plants rarely produce fruit and when they do, the fruit is stunted and twisted. However, in the rare scenario that a diseased plant does produce fruit that reaches maturity, it is edible. Banana bunchy top disease caused by a single-strand DNA virus, the banana bunchy top virus(BBTV). BBTV is the sole member of the genus Babuvirus in the family Nanoviridae. The genome of BBTV is made up of at least six circular, single-stranded DNA components, each about 1 kilo-base pair in length.
There are no resistant varieties of banana against BBTV, so the most common method of control is chemical control of the aphid vectors.The agriculture department, however, recently obtained an EPA waiver for the pesticide Provado is a means of controlling the aphids that spread the disease.
Q. Difference between Archaebacteria and Eubacteria ?
Ans, - Archaebacteria are simple in their organization where as , Eubacteria are more complex. - Archaebacteria are Rod, Sphere, plate, spiral, flat in shape , where as Eubacteria are Cocci, bacilli, vibrio, rods, filaments or spirochetes in shape. - Archaebacteria cell wall is composed of psuedopeptidoglycans. Whereas as, Eubacteria is composed of peptidoglycans with muriatic acid. - Archaebacteria found in Extreme environments where as, Eubacteria found everywhere on Earth. - Introns are Present in Archaebacteria and Absent in Eubacteria. - Archaebacteria neither exhibit Glycolysis nor Kreb's Cycle, and there in Eubacteria both the cycles exhibit. - Membrane lipids in Archaebacteria are Ether linked, Branched, alphabetic chains, containing D- glycerol phosphate and on the other side, Eubacteria are esters linked, straight chained fatty acid, containing L- glycerol phosphate. - Archaebacteria has Three types-- methanogens, halophiles and thermophiles. - Eubacteria has two types-- Gram positive and Gram negative. EXAMPLES include-- - Archaebacteria: halobacterium, lokiarchaeum, thermoproteus, pyrobaculum, thermoplastic and ferro plasma. - Eubacteria: mycobacteria, bacillus, sporohalobacter,clostridium and anaerobacter.
Viruses are important to the study of molecular and cell biology as they provide simple systems that can be used to manipulate and investigate the functions of cells. The study and use of viruses have provided valuable information about aspects of cell biology. For example, viruses have been useful in the study of genetics and helped our understanding of the basic mechanisms of molecular genetics, such as DNA replication, transcription, RNA processing, translation, protein transport, and immunology.
The term “the great plate count Anomaly ” was coined by Staley and Konopka in 1985 to describe the difference in orders of magnitude between the numbers of cells from natural environments that form colonies on agar media and the numbers countable by microscopic examination. Marine ecosystems are a well-studied example of this phenomenon: only 0.01 to 0.1% of oceanic marine bacterial cells produce colonies by standard plating techniques. There are numerous explanations for this anomaly. For example, species that would otherwise be “culturable” may fail to grow because their growth state in nature, such as dormancy, prevents adjustment to conditions found in the medium used for the plate counts. This hypothesis does not explain the substantial discrepancy between 16S rRNA genes recovered from seawater directly by cloning and those of the readily cultured marine taxa. Another explanation for the “great plate count anomaly” is that many of the microbial species that dominate in natural settings are not adapted for growth in media containing high concentrations of complex organic carbon. Many microorganisms may need oligotrophic or other fastidious conditions to be successfully cultured. There are many examples of microbial strains that are common in nature, but can only be cultivated by specialized techniques
Why bacteria have different shapes ? Because of 3 broad considerations suggest that bacterial shapes are not accidental but are biologically important. Cells adopt uniform morphologies from among a wide variety of possibilities. Some cells modify their shape as conditions demand and morphology can be tracked through evolutionary lineages.All of these imply that shape is selectable feature that aids survival. Cell shape is driven by 8 general considerations as nutrient access,cell division and segregation, attachment to surfaces,active motility,need to escape predators,advantages of cellular differentiation and passive dispersal.Thus bacteria respond to these forces by performing a type of calculus(change),integraty over a no.of environmental and behavioral factor to produce size and shape that are optimal for circumstances in which they live.
Difference between virus,viroids and virusoids. Viroids consist only of a short strand of circular RNA capable of self-replication.Unlike viruses, viroids do not have a protein coat to protect their genetic information. Virusoids are subviral particles best described as non–self-replicating ssRNAs. RNA replication of virusoids is similar to that of viroids but, unlike viroids, virusoids require that the cell also has to be infected with a specific “helper” virus. Also virusoids contain protein coat unlike viroids.
Virus infecting banana: Banana bunchy top virus (BBTV) is responsible for infecting banana. Often BBTD, banana bunchy top disease, gets its name from the bunchy appearance of infected plants. Virus infecting honey bees include: Dicistroviruses.
What are virusoids? Virusoids are type of pathogenic RNA that can infect important agricultural crops , which are subviral particles best described as non–self-replicating ssRNAs. RNA replication of virusoids is similar to that of viroids but, unlike viroids, virusoids require that the cell also be infected with a specific helper virus.
Cell Shape:- The cell shape of bacteria depends on the cell wall composition, peptidoglycan in cell wall is a mesh of peptides and saccharides that provides rigidity and strength to the bacteria. Also there are proteins, responsible for flipping the Lipid are believed to give cell shape, viz. FtsW, RodA, and SpoVE. FtsW is considered the main enzyme for most cell growth. RodA is found in "rod shaped bacteria" and is considered necessary for cell elongation. SpoVE is used to build the thick cell walls of bacterial spores. By controlling how Lipid is delivered to the growing cell wall, these proteins play a role in controlling cell shape and also the environmental factors do take part, but everytime that are not enough to decide the shape of bacterial cell. Thus this might be the reason to provide shape to cell and highly motile bacteria are usually rods with a specific (optimal) shape and size, while the movement through viscous fluids seems to a favor spiral shape. But since multiple selective forces are always in play, there is at the moment no way to predict cell shape based on the environment or vice versa.
Question:-Mechanism of Horizontal Gene Transfer Answer:-Horizontal gene transfer may occur via three main mechanisms: transformation,transduction or conjugation.
1. Transformation involves uptake of short fragments of naked DNA by naturally transformable bacteria. 2. Transduction involves transfer of DNA from one bacterium into another via bacteriophages. 3. Conjugation involves transfer of DNA via sexual pilus and requires cell –to-cell contact. DNA fragments that contain resistance genes from resistant donors can then make previously susceptible bacteria express resistance as coded by these newly acquired resistance genes.
According to 9th report of ICTV(The International Committee on Taxonomy of Viruses)
Although many viruses have been classified into genera in this Report, a number of relatively well-characterized viruses are yet, for various reasons, to be assigned to existing genera/families or have been sufficiently distinguished from recognized viruses to form types and members for new genera. Some examples are listed here for which certain key characteristics are known, most notably a significant amount of sequence data along with some well-described biological and biophysical properties. There are, however, a number of viruses has been undescribed genera and families, and that underline the fact that developing a universally applicable virus taxonomy is a continuously evolving process. Eg. Archaeal Viruses Haloarcula phage SH1 Halorubrum pleomorphic virus 1 (HRPV-1)
Question:-Difference between splitters and lumpers Answer:-A "lumper" is a taxonomist who group by similar traits, assuming that differences are not as important as similarities. And place organisms which share a few major characteristics in the same group. When two named species are discovered to be of the same species, the older species name is usually retained, and the newer species name dropped, a process called synonymization or convivially, as lumping. A "splitter" is a taxonomist who takes precise definitions, and creates new categories to classify organism on the basis of the smallest known difference, so every small difference is considered sufficient to create a new separate group. Dividing a taxon into multiple, often new, taxa is called splitting.
Which is the largest virus known till date? 1. The biggest known viruses are Mimivirus (750 nanometer capsid, 1.2 million base pair DNA) and Mimiirus is a virus of the amoebaAcanthamoeba polyphaga and was first isolated from a cooling tower in England in 1992. 2. Megavirus (680 nanometer capsid, 1.3 million base pair DNA)
QUESTION: Which is the smallest virus known till date?Presently, PCVs are the smallest viruses found in animals. The diameter of their virions ranges from 17 to 21 nanometres in size. Their genomes consist of single-stranded DNA that is circular in nature with about 1759 (PCV1) and 1767-1768 (PCV2) nucleotides sequence.
Reverse transcribing DNA viruses use reverse transcriptase to replicate their genomes.Hepatitis B virus (HBV)is one of the best studied reverse transcribing DNA viruses. HBV virions are 42 nm spherical particle that contain the viral genome. The HBV genome is a circular dsDNA molecule that consist of one complete but nicked strand and a complementary strand that has a large gap. After infecting a host cell, the viral gapped DNA is released into nucleus and gap is filled yielding a closed circular DNA. Transcription of viral genes occurs in the nucleus using host RNA polymerase and yield several mRNAs.
Which was the first animal virus discovered and had a large impact on the economy? Foot-and-mouth disease virus(FMDV) was the first animal virus discovered in 1929 and had a significant impact on world economies and public health. Foot-and-mouth virus cause Foot-and-mouth disease which has a broad host range that includes most hoof stock (including pigs but not horses) and several other mammalian species. FMD virus is a single-stranded positive-sense RNA virus that belongs to the genus Aphthovirus of the Picornaviridae family. FMD virus (FMDV) is divided into seven antigenically distinct serotypes, A, O, C, Asia 1, and South African Territories (SATs) 1, 2, and 3
What virus cannot do? (1) They can't reproduce on their own. They need to infect or invade a host cell. That host cell will do all the work to duplicate the virus. (2) They don't respond to anything. You can poke them or set up barriers, it doesn't matter. They either function or they are destroyed. (3) They don't really have any working parts. While there some advanced viruses that seem fancy, viruses don't have any of the parts you would normally think of when you think of a cell. They have no nuclei, mitochondria, or ribosomes. Some viruses do not even have cytoplasm.
BACTERIOPHAGE THERAPY In an era where antibiotic-resistant bacterial infections are on the rise, phages provide numerous advantages, along with relatively few disadvantages. Today ,much more is known about bacteriophages than in the 1930s when phage therapy first appeared and began to spread to many countries. In terms of “Pros,” phages can be bactericidal, can increase in number over the course of treatment, tend to only minimally disrupt normal flora, are equally effective against antibiotic-sensitive and antibiotic-resistant bacteria, often are easily discovered, seem to be capable of disrupting bacterial biofilms, and can have low inherent toxicities. In addition to these assets, we consider aspects of phage therapy that can contribute to its safety, economics, or convenience, but in ways that are perhaps less essential to the phage potential to combat bacteria. Concerns about using phages as antibacterial agents can be distinguished into four categories: (1) Phage selection, (2) Phage host-range limitations, (3) The “uniqueness” of phages as pharmaceuticals, and (4) Unfamiliarity with phages. There are diverse ways in which phages interact with human cells. Phages can modulate innate immunity via phagocytosis and cytokine responses, but also impact adaptive immunity via effects on antibody production and effector polarization. It is thus important to consider whether phage interactions with commensal bacteria could alter community compositions in ways that impact the function of the immune system and influence the spread of pathogenic viruses, or even bacteria. So, still the discussions are going on whether bacteriophage therapy would prove useful or harmful as a treatment. References:- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3278648/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356784/
1892 – Dimitrii Ivanovsky observed that agent of tobacco mosaic disease passes through porcelain filters that retain bacteria. 1898 – Marcus Beijerinck makes the same observation; concludes that the pathogen must be a distinctive agent. 1898 – Friedrich Loeffler and Paul Frosch (former students of Koch), find that causative agent of foot-and-mouth disease is filterable (the first animal virus). 1901 – Yellow fever virus – Walter Reed (the first human virus). 1903 – Rabies virus (Paul Remlinger, Riffat-Bay, Alfonso di Vestea). 1906 – Variola virus (Negri). 1908 – Poliovirus (Karl Landsteiner and E. Popper); chicken leukemia virus (Ellerman, Bang). 1911 – Rous sarcoma virus (Peyton Rous). 1915 – Bacteriophages -Frederik Twort, Felix D’Herelle. 1931 – Swine influenza virus (Shope). 1933 – Human influenza virus (Smith).
The name virus was coined from the Latin word meaning slimy liquid or poison. It was originally used to described any infectious agent, including the agent of tobacco mosaic disease, tobacco mosaic virus. In the early years of discovery, viruses were referred to as filterable agents. Only later was the term virus restricted to filterable agents that require a living host for propagation.
Few definitions :- Virus - most ubiquitous entity that is infectious and is obligate intracellular parasitic organism.
Viriod - the smallest infectious pathogens known, which are composed solely of a short strand of circular, single-stranded RNA that lacks protein coating.
Virion - it is an entire virus particle consisting of an outer protein shell called a capsid and an inner core of nucleic acid (either RNA or DNA).
Prions - initially thought to be virus which replicated slowly within their host but, despite much work, no nucleic acid has been found in association with infectious materials. Aberrant forms of normal cellular proteins which can induce changes in the shape of their normal structure with catastrophic consequences for the host. In short, a prion is a type of protein that can trigger normal proteins to fold abnormally.
Prophage - The genome of Bacteriophage, when inserted and integrated into bacterial genome, which undergo to make its copies, without disrupting the cell and it is latent form so stays in the cell and divides with the division of bacterial genome.
Episome - It is the genetic material of Bacteriophage, that can replicate in absence or presence of host genome and so they can exist as independent of the main body of genetic material. DNA in some lysogenic bacteriophages act as episomes, integrating into the genome and persisting as Prophage.
Lysogen - A lysogen is a bacterial cell which can produce and transfer the ability to produce a phage.
Lysogeny - Lysogeny is characterized by integration of the bacteriophage nucleic acid into the host bacterium's genome. It is one of the two cycles of viral reproduction.
Lysogenic conversion - In the lysogenic state the phage does not represent a significant disadvantage for the survival of the host. In fact, in contrast to the situation with latent animal viruses where no advantage for the host is known, lysogeny often carries a strong selective value for the bacterium, since temperate phages frequently confer new characteristics on the host. This phenomenon manifests itself in many ways and is referred to as lysogenic conversion.
INFECTION OF BACTERIAL AND ARCHEAEAL CELLS : LYSIS AND LYSOGENY.
There are 2 types of phage 1.virulent phage 2.temperate phage. Virulent phage -one that has only one option: to begin multiplying immediatley upon entering its bacterial host, followed by release from the hostby lysis. T4 is the example of virulent phage. Temperate phages that have 2 options : upon entry into host cell, they can multiply like the virulent phages and lyse the host cell, or they can remain within host withiut destroying it. Bacteriophage lambda is an example of this type of phage. The relation between a temperate phage and its host is called lysogeny. The form of virus that remians within its host is called a prophage. The infected bacteria are called lysogens or lysogenic bacteria. Lysogenic bacteria reproduce and in most other ways appear to be perfectly normal. However, they have two distinct characteristics. 1.they can not be reinfected by same virus - that is they have immunity to superinfection. 2.they can switch from lysogenic cycle to lytic cycle.
QUESTION:Which was the first DNA based genome sequenced? Enterobacteria phage phiX174 The phi X 174 (or ΦX174) bacteriophage is a single-stranded DNA (ssDNA) virus that infects Escherichia coli, and the first DNA-based genome to be sequenced.
1. The essential principles of virus nomenclature are:
(i) to aim for stability; (ii) to avoid or reject the use of names which might cause error or confusion; (iii) to avoid the unnecessary creation of names.
2. Nomenclature of viruses is independent of other biological nomenclature. Virus taxon nomenclature is recognized as an exception in the proposed International Code of Bionomenclature (BioCode).
3. The primary purpose of naming a taxon is to supply a means of referring to the taxon, rather than to indicate the characters or history of the taxon.
4. The name of a taxon has no official status until it has been approved by the ICTV.
QUESTION:which is the most conserved genome segments for life detection? On Earth, very simple but powerful methods to detect and classify broad taxa of life by the polymerase chain reaction (PCR) are now standard practice. Using DNA primers corresponding to the 16S ribosomal RNA gene, one can survey a sample from any environment for its microbial inhabitants. Due to massive meteoritic exchange between Earth and Mars (as well as other planets), a reasonable case can be made for life on Mars or other planets to be related to life on Earth. In this case, the supremely sensitive technologies used to study life on Earth, including in extreme environments, can be applied to the search for life on other planets. Though the 16S gene has become the standard for life detection on Earth, no genome comparisons have established that the ribosomal genes are, in fact, the most conserved DNA segments across the kingdoms of life. Scientists present a computational comparison of full genomes from 13 diverse organisms from the Archaea, Bacteria, and Eucarya to identify genetic sequences conserved across the widest divisions of life. Their results identify the 16S and 23S ribosomal RNA genes as well as other universally conserved nucleotide sequences in genes encoding particular classes of transfer RNAs and within the nucleotide binding domains of ABC transporters as the most conserved DNA sequence segments across phylogeny. This set of sequences defines a core set of DNA regions that have changed the least over billions of years of evolution and provides a means to identify and classify divergent life, including ancestrally related life on other planets.
QUESTION: Which was the first RNA based genome sequenced? The first genome, that of RNA bacteriophage MS2, was sequenced in 1976.This was followed by the genome of bacteriophage ϕX174. These are some of the smallest known genomes with only four and ten genes, respectively. Sequence comparative genomics had a real head start with two astonishing discoveries , First, it has been shown that RNA-containing retroviruses shared a conserved replicative enzyme, the reverse transcriptase, with two groups of DNA viruses, Second, it turned out that small RNA viruses infecting animals (such as polio and foot-and-mouth disease) and those infecting plants (cowpea mosaic virus) shared not only significant sequence similarity that allowed the identification of homologous genes, but also, in part, the order of these genes in their genomes. Reference:- https://www.ncbi.nlm.nih.gov/books/NBK20263/
Que : why is agar agar spelled twice? The agar agar is called twice because the word agar is derived from agar - agar which is the malay name for red alage which is known as gigartina giacilaria so it's called twice
1892 – Dimitrii Ivanovsky observed that agent of tobacco mosaic disease passes through porcelain filters that retain bacteria 1898 – Marcus Beijerinck makes the same observation; concludes that the pathogen must be a distinctive agent 1898 – Friedrich Loeffler and Paul Frosch (former students of Koch), find that causative agent of foot-and-mouth disease is filterable (the first animal virus) 1901 – Yellow fever virus – Walter Reed (the first human virus) 1903 – Rabies virus (Remlinger, Riffat-Bay) 1906 – Variola virus (Negri) 1908 – Poliovirus (Karl Landsteiner and E. Popper); chicken leukemia virus (Ellerman, Bang) 1911 – Rous sarcoma virus (Peyton Rous) 1915 – Bacteriophages -Frederik Twort, Felix D’Herelle 1931 – Swine influenza virus (Shope) 1933 – Human influenza virus (Smith)
Archaea though similar in shape and size to bacteria have many genes in common with eukaryotes.Also they have metabolic pathways that are similar to eukaryotic pathways.Notably closely related are the enzymes involved in trancription and translation. More studies on archaea would fill up the gaps in knowledge about eukaryotic evolution.As microbiology undergoes a renaissance, fuelled in part by developments in new sequencing technologies, the massive diversity and abundance of microbes becomes yet more obvious. The Archaea have traditionally been perceived as a minor group of organisms forced to evolve into environmental niches not occupied by their more ‘successful’ and ‘vigorous’ counterparts, the bacteria. Here we outline some of the evidence gathered by an increasingly large and productive group of scientists that demonstrates not only that the Archaea contribute significantly to global nutrient cycling, but also that they compete successfully in ‘mainstream’ environments. Recent data suggest that the Archaea provide the major routes for ammonia oxidation in the environment. Archaea also have huge economic potential that to date has only been fully realized in the production of thermostable polymerases. Archaea have furnished us with key paradigms for understanding fundamentally conserved processes across all domains of life. In addition, they have provided numerous exemplars of novel biological mechanisms that provide us with a much broader view of the forms that life can take and the way in which micro-organisms can interact with other species. That this information has been garnered in a relatively short period of time, and appears to represent only a small proportion of what the Archaea have to offer, should provide further incentives to microbiologists to investigate the underlying biology of this fascinating domain.
Que:Differe between facultative aerobics and anaerobics?
The difference lies in their intermediate metabolism and the way they obtain the energy necessary for their growth and multiplication, the optional aerobic term establishes as the ideal growth condition the presence of oxygen, however at lower partial pressures of oxygen, these bacteria can follow growing. While the facultative anaerobic term establishes an ideal growth condition for the absence of oxygen, however, if the oxygen partial pressure rises in the medium, it is non-toxic to these microorganisms and can continue to grow.
Is there any similarities between two kinds of scientists, which includes one type is arrogant, intelligent and powerful and the other type is calm, smart and strong....
ReplyDeleteAnd one answer can be their madness to learn the topic or to understand the whole matter makes them similar....
Scientists are very excellent in facing failures and rising again after that failure which every scientist would have faced somewhere sometime in their experiment.
ReplyDeleteThe agar agar is called twice because the word agar is derived from agar - agar which is the malay name for red alage which is known as gigartina giacilaria
ReplyDeleteSir once you asked that I'm growth curve during death phase there decline the line but the cells remain constant so why did the curve showed decline. The reason is that the dead bacteria settles down so that the light is not passed through them nd so they show decline phase
ReplyDeleteIn death phase, cell number or cell mass concentration drop after death because of the autolysis, cell membrane is damage and cytoplasm leaks out, as a result refractive index decreases and also particulate matters decreases and therefore OD drops because of smaller scattering of light.
DeleteSir once you asked that I'm growth curve during death phase there decline the line but the cells remain constant so why did the curve showed decline. The reason is that the dead bacteria settles down so that the light is not passed through them nd so they show decline phase
ReplyDeleteBut if light is not passed through them than how we get OD of decline phase and even in decline phase bacteria are not live.
ReplyDeleteDuring decline phase the bacterial cells either settle down or they undergo cell death. There are two hypothesis through which it can be explained. The first one is programmed cell survival wherein the cells, undergo s dormant stage, in which the cell is viable but is non-culturable. Whereas the other method is in which the cell undergoes programmed cell death leading to autolysis and death. The decision of choosing path depends on individual cells. The lysed cells leak their cellular content out in medium which is used by the unlysed cells. Hence due to autolysis the optical density decreases as the cells are dying. Also the rate of growth is lesser than the rate of decline or death hence the OD is lower.
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ReplyDeleteA question was asked why most of the organisms reside in large intestine?Ans is that the bacterial population in the large intestine digest carbohydrates, proteins and lipids that escape digestion and absorption in small intestine.So the normal sugars get absorb in small intestine.
ReplyDeleteAccording to me the answer should be, gut microbes release certain metabolites which human body is unable to synthesise and also they help in absorption,as ileum and large intestine are the sites for absorption of substances, say for example lactobacillus help in absorption of tryptophan.
ReplyDeleteBacteria in the large intestine also make some important substances, such as vitamin K, which play an important role in blood clotting.
DeleteYes it can be both because many of the microbes form certain metabolites but most of the fermenting sugars are also important for humans and certain byproducts too.There are many different answers.
ReplyDeleteQUESTION: Why decline phase have decreased O.D. value?
ReplyDeleteANSWER: dead gram+ bacteria lysed (autolysis). SO concentration of cells really decrease. in the case of gram-, before lysis dead cells swell (refractive index decrease). this process also leads to decrease in O.D.
most of the time O.D. of bacteria decrease due to autolysis but be very careful the O.D. value can be constant when medium is less toxic and autolysis very low.
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ReplyDeleteWhy some time generation time and line of growth curve is not relevant to each other?
ReplyDeleteGeneration time and line of curve are relevant to each other but the generation depend on the slop which shows the time laps which taken for calculation. So in the comparison it may be verry so this situation happen
DeleteSynchronous culture is the cell culture where is showing the cells that all are in same growth rate . There are many factors that affects the cell cycle basically normal cultures have cells in all phages of cell cycle synchronous cultures can be obtained in many ways like it can be obtained by changing the external conditions as to arrest the growth of all cells in the culture the second option is by adding chemicals like growth inhibitors,after growth has completely stopped for all cells the inhibitors can be removed from the culture the cells will than begin to grow in synchronous culture
ReplyDeleteQ:why oxygen level is stable in atmosphere
ReplyDeleteAns:Its not stable
In the new study, researchers calculated past atmospheric oxygen levels by looking at air trapped inside ancient polar ice samples. Specifically, they looked at samples from Greenland and Antarctica.
The new estimates suggest that atmospheric oxygen levels have fallen by 0.7 percent over the past 800,000 years. The scientists concluded that oxygen sinks — processes that removed oxygen from the air — were about 1.7 percent larger than oxygen sources during this time.
Roll no:19MBT019
DeleteWhen the life bigin on earth there was no usage of oxygen because the aerobic life not take place. After the evolution of cell than the oxygen utilized. At same time the oxygen is generated by cynobacteria, algae and higher plants.in this way the oxygen levwl is constant on earth.
DeleteIf microorganisms get disappeared how our world would be?(19MMB027)
ReplyDelete1 Microorganisms play a crucial role in decomposition of organic matters both in soil and ocean so first of all accumulation of such matters will increase on earth.
2 Cyanobacteria can convert atmospheric nitrogen into ammonium and nitrate ions that can be easily absorbed by the plants for their growth and we consume plants for energy so this process will result into improper growth of both.
3 The microorganisms helping in removal of pollutants by utilizing it as their substrate and indirectly helping us and so pollution will arise and will keep arising more and more in their absence.
4 Our immune system would become weak and it will affect upcoming generation also.
The oxygen level when the earth formed was zero, then the first life form occurred in the form of cyanobacteria and they started forming free oxygen in environment by utilising certain compounds like carbon dioxide, sulphur oxides, iron as their energy source and oxygen was observed in atmosphere ,slowly it increased upto certain concentration and that bacteria started using that oxygen and evolving in that environment. Now, today there is 21% oxygen which is maintained because of certain reasons like global warming, tectonic movement, etc. Diatoms also play major role, as they are responsible to maintain oxygen level in atmosphere. Also if the oxygen is increased in atmosphere, it will support combustion and oxygen takes part in the burning reaction. By considering certain parameters some increase oxygen concentration, while some decreases. Thus oxygen amount is maintained.
ReplyDeleteWhat would be the earth without microorganisms? (-by udita pal 19MBT028)
ReplyDeleteWell life in earth will not be possible without microorganisms. As microorganisms are very useful in many ways. They are efficient recyclers as they play a critical role in decomposing organic matter.
2.Also there are microorganisms those play an important role in fixing nitrogen and make them available to plants for their survival.
3. Microorganism also play an important role to fight pollution.As bioremediation uses certain bacteria that digest toxic substance and convert them into less harmful substance.
There are certain bacteria residing in our digestive system that are good gut bacteria and essential for the body.
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ReplyDeleteThis comment has been removed by the author.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteWhy oxygen level is stable on earth?
ReplyDeleteThe reason why the oxygen percentage is constant for many years is because that the green plants who are capable of photosynthesis are taking up CO2 and producing 02 in exchange, Amazon forest are said to be responsible for 20% of the world's Oxygen and there are also called lungs of earth Some Oxygen is also made when ozone molecules are broke by UV rays of sun
1) access O2 produced but absorbed in ocean and seabed rock in form of iron oxide on the sea floor
2)O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer.
So this way o2 is stable
But right now o2 level slightly decrease because of industrial co2 production.
And O2 level directly depend on co2...
Queen:which enzyme is fastest enzyme?
ReplyDeleteAns:Carbonic anhydrase .Enzyme activity depends on turnover number and carbonic anhydrase's turnover number is 4×b10000000.(19mmb028)
Why oxygen level is stable in atmosphere?(-by Dinky Motwani 19MMB015)
ReplyDeleteOxygen level is stable in atmosphere because the green plants who are capable of photosynthesis are taking up CO2 and producing O2 in exchange. Amazon Forest are said to be responsible for 20% of the world's oxygen. The content of oxygen mainly depends on the content of CO2.
Why oxygen level is stable in the earth?
ReplyDeleteAns. Oxygen levels first rised from 2-4 percent to 21 percent a few billion years ago. Actually the oxygen levels are depleting at a very slow rate that the rate of depletion seems negligible. The photosynthetic bacteria and other microorganisms like algae provide a huge amount of oxygen. Apart from them, rainforests are the major source of oxygen. Apart from the photosynthetic organisms, there are organisms which reduce the iron, sulfur and nitrogen oxides thereby retaining the oxygen levels on the earth. Simultaneously the consumption of oxygen occurs in various ways. The degradation of dead organisms also releases oxygen thus percentage of oxygen is maintained on earth.
Que. Why agar is used twice in the name agar powder?
ReplyDeleteAns. Agar powder or agar is made up of two polysaccharides namely agarose and agaropectin. The agar agar may be named as such due to the presence of this two polysaccharides from which it is made. The agar powder is made from red algae known as agarophytes and it belongs to the rhodophyta group.
QUESTION:How does oxygen content in atmosphere remain constant at 21%?
ReplyDeleteoxygen is regulated because an increase in oxygen increases the consumption of oxygen and/or decreases the rate of oxygen production. A decrease in oxygen has opposite effects. The % oxygen has varied a lot over the lifespan of the earth, but it is much like climate where it very seldom changes dramatically in a short amount of time (short in relation to the lifespan of earth) even some studies shows oxygen levels are decreasing globally due to fossil-fuel burning. but this change is very negligible.
QUESTION: Why agar powder also called agar-agar powder?
ReplyDeleteThe word "agar" originally comes from agar-agar, the Malay name for red algae (Gigartina, Gracilaria) from which the agar powder is produced. so agar powder also called as agar-agar powder.
QUESTION:What should be the ideal depth of butt in agar slant?
ReplyDeleteideal depth of butt in agar slant is 2 cm to 2.5 cm.
QUESTION:Which bacteria have minimum generation time?
ReplyDeleteThe bacterium Vibrio natriegens can double with a generation time of less than 10 min.it is fastest growing bacterium known.
QUESTION:Why large intestine of human contain highest amount of microorganisms?
ReplyDeletelarge intestine have highest amount of microorganism because it provide more time to microorganisms to make good surface contact and establish better colonisation and also rich in nutrient compare to other area of body.
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ReplyDeleteQUESTION:Which enzyme is fastest?
ReplyDeleteThe hydration of carbon dioxide is catalyzed by an enzyme—namely, carbonic anhydrase. The transfer of CO2 from the tissues into the blood and then to the alveolar air catalyzed by this enzyme. Carbonic anhydrase is fastest enzymes known. Each enzyme molecule can hydrate 10^6 molecules of CO2 per second. This catalyzed reaction is 10^7 times as fast as the uncatalyzed one.
Fastest growing Bacteria and also Microorganism on Earth is:-
ReplyDelete_C. perfringens_ generation time has been reported to be as rapid as 7.4 min in autoclaved ground beef in bacteria;
While there are certain microorganisms such as _M. pyrifera_ are the fastest growing multicellular brown algae to grow at the speed of 2ft per day that means its generation time is in few seconds
For ideal slant, in 7ml volume, 16×125 mm tube, 1 inch deep butt act as ideal slant for maintaining bacterial culture.
ReplyDeleteQUESTION:Which is the largest bacterial cell?
ReplyDeleteThiomargarita namibiensis is the largest bacteria in present, with a diameter of 750 μm. Thiomargarita namibiensis are large enough to be visible to the naked eye.
QUESTION:What are the advantages for microbes being in biofilm?
ReplyDeleteBiofilm is a strong and dynamic structure that confers a broad range of advantages to its members, such as adhesion/cohesion capabilities, mechanical properties, nutritional sources, metabolite exchange platform, cellular communication, protection and resistance to drugs. The EPS of the biofilm matrix is negatively charged and hydrophobic. These properties enable the biofilm to concentrate ions and dissolved organic carbon compounds from the oligotrophic bulk fluid. Thus biofilms can grow in nutrient conditions that do not permit the growth of planktonic cells.
QUESTION :- Symbiotic association found in 2019?
ReplyDeleteLichen like symbiotic association of fungi with bacteria.
Filamentous hyphae with coccoidal cyanobacteria found im marine phosphorite of south china. It shows that fungi developed symbiotic partnership with photoautotrophs before evolution of algae and vascular plants.
QUESTION :- How microbes survive at higher depth of earth crust?
ReplyDeleteIn earth crust cracks, fractures and openings of rocks are observed. In this surface ground water is observed which is 1billion year old. When rock and ground water came into contact serpentinization occurs which release small amount of H2. The environment at this place is oligotrophic means lack of nutrients. Microbes which are observed they are autotrophic (chemolithoautotrophs) in nature. They utilize H2 as energy source and survive.
Example :
1) Dethiobacter - H2 using bacteria
2) Dethiosulfatibacter
3) uncultured clostridium species.
These all microbes are identified by 16S rRNA sequencing because they are not culturable.
Scientists may assume that some CO2 using bacteria are may be present due to the fossils of plants and animals which provides carbon source.
19MBT009 (Devashri Gandhi)
ReplyDeleteWhy we use "Fresh Meat Of OX Heart as a medium?
As i read Ox heart meat is used with nutrient broth in the "Robertson's Cooked Meat Medium",
Robertson’s Cooked Meat (RCM) medium is used for the cultivation of aerobic, microaerophilic, and anaerobic microorganisms, especially Clostridium species. It is also known as Cooked Meat Broth (CMB) as it contains pieces of fat free minced cooked meat of ox heart and nutrient broth. It supports the growth of both spore-forming and non-spore forming obligate anaerobes and also differentiate between putrefactive and saccharolytic species.
Oxygen in culture media can be reduced by various agents such as glucose, thioglycollate, cooked meat pieces, cysteine and ascorbic acid.
Thioglycollate broth which contains nutrient broth and 1% thioglycollate is also used to cultivate anerobes
How "PUTREFYING BACTERIA" works in PUTREFACTION OF MILK?
ReplyDeleteAs in unpasteurized milk, it contains various species of bacteria, yeasts, and molds. Initially, the dominant organism is the bacterium Lactococcus (Streptococcus) lactis, which breaks down the milk sugar lactose, forming lactic acid as an end-product (figure 30.4). The resulting acid inhibits the growth of most other organisms in the milk, and eventually enough acid is produced to prevent even the further growth of L. lactis. The acid sours the milk and also curdles it, a result of denaturation of the milk proteins. Bacterial species such as Lactobacillus casei and Lactobacillus bulgaricus can multiply in this highly acidic environment. These species metabolize any remaining sugar, forming more acid until their growth is also inhibited. Yeasts and molds, which grow very well in this highly acidic environment, then become the dominant group and convert the lactic acid into non-acidic products. Because most of the sugar has already been used, the streptococci and lactobacilli cannot resume multiplication since they require this substrate. Milk protein (casein) is still available and can be utilized for energy by bacteria of the spore-forming genus Bacillus, and some other bacteria, all of which secrete proteolytic enzymes that digest the protein. This breakdown of protein, known as putrefaction, yields a completely clear and very odorous product. The milk thus goes through a succession of changes with time, first souring and finally putrefying.
What is a "MICROBIAL MAT" Or "How MICROBIAL COMMUNITY by forming biofilms in MICROBIAL MAT looks like?
ReplyDeleteA microbial mat is a thick, dense, highly organized structure composed of distinct layers. Frequently they are green, pink, and black, which indicate the growth of different groups of microorganisms. The green layer is the uppermost and is typically composed of various species of cyanobacteria. The color is due to the photosynthetic pigments of these microbes. The pink layer directly below consists of purple sulfur bacteria. The light-harvesting pigments of these anoxygenic phototrophs can use wavelengths of light not collected by the cyanobacteria. The black layer at the bottom results from iron molecules reacting with hydrogen sulfide produced by a group of bacteria called sulfate-reducers. These obligate anaerobes oxidize the organic compounds produced by the photosynthetic bacteria growing in the upper layers of the mat, using sulfate as a terminal electron acceptor.
I can't attach the photo here as comment box not permitting me to do so.
So anyone wants to see pic of Microbial pit can find it on google
What are the reasons for "Decrease in Growth rate after late log phase"?
ReplyDelete1) first reason
Cells' activities shift as they enter in " late log phase", which marks the transition to stationary phase. This change occurs in response to multiple factors that are sure to be in a closed system, such as depletion of nutrients and formation of waste products. If the cells are able to form endospores, they initiate the process of sporulation. If they cannot, they "shrink" in preparation for the starvation conditions ahead. The cells become rounder in shape and more resistant to harmful chemicals and radiation. Changes in the composition of their cell wall and cytoplasmic membrane also occur. As their surrounding environment changes, cells begin synthesizing different enzymes and other proteins, which collectively give rise to a new group of metabolites, termed secondary metabolites. Commercially, the most important secondary metabolites are antibiotics. These compounds are produced by many bacterial spe. and inhibit the growth of or kill other organisms.
2) second reason
As per "ALLEE'S PRINCIPLE"
Population Dynamics which stated due to competition for resources, a population will experience a reduced in overall Growth rate at Higher Density and increased growth at the lower density due to reverse holds or Negative regulation of population density.
3) Third reason
When population density is very low then the Interaction between two cell for the further metabolic activity or reproductive activity is also low or nill there for important molecules diffuse out due to leaky nature of the cell in surrounding area but bacterial cell due distance is very much ,cant utilize it and ultimately growth rate will decrese.
How "VITAMIN C" is important in INFECTION and LIGHTING of SKIN ?
ReplyDeleteAs i read on NCBI,
Vitamin C appears to be able to both prevent and treat respiratory and systemic infections.
Vitamin C accumulates in phagocytic cells, such as neutrophils, and can enhance chemotaxis, phagocytosis, generation of reactive oxygen species, and ultimately microbial killing. It is also needed for apoptosis and clearance of the spent neutrophils from sites of infection by macrophages, thereby decreasing necrosis and potential tissue damage.
For skin,
pleiotropic functions related to its ability to donate electrons. It is a potent antioxidant and a cofactor for a family of biosynthetic and gene regulatory enzymes. Vitamin C contributes to immune defense by supporting various cellular functions of both the innate and adaptive immune system. Vitamin C supports epithelial barrier function against pathogens and promotes the oxidant scavenging activity of the skin, thereby potentially protecting against environmental oxidative stress.
MECHANISM of "QUORUM SENSING"
ReplyDeleteQuorum Sensing is the ability to detect and to respond to cell population density by gene regulation
This process includes secreting the signaling molecules, e.g, c-AMP, other QS signaling molecules, concentration of signaling molecules , regulation of gene transcription..
If cell density is low then this signaling molecules must be diffuse away..
If cell density is high then local concentration may exceed its normal level and elicits the gene expression by feed back mechanism of regulation..
" DISCOVERY of NEW BACTERIAL SPECIES"
ReplyDelete"Staphylococcus cornubiensis"
discovered on a man in Cornwall. The bacteria was found on a 64 year old man seeking treatment for cellulitis. When researchers attempted to find the cause of this skin infection, they found the bacteria,
The discovery of S. cornubiensis was reported in the International Journal of Systematic and Evolutionary Microbiology along with evidence that this is a new species.
After collecting S. cornubiensis from the skin infection, researchers at the University of Exeter Medical School and the Royal Cornwall Hospital found that it had not been reported before. They think it is part of a group of bacteria known as the Staphylococcus intermedius group (SIG). This is a group of harmful bacteria which are usually passed onto humans from pet dogs.
The SIG group of bacteria contains bacterial species Staphylococcus intermedius and Staphylococcus pseudointermedius, which have been identified as potential zoonotic threats, meaning there is a risk of these bacteria spreading to humans from animals and causing infection.
ReplyDeleteElusive Asgard Archaea Finally Cultured in Lab
12 years of endevour reveals Prometheoarchaeum as a tentacled cell, living in a symbiotic relationship with methane-producing microbes...
With the cultured microbe in hand, the researchers sequenced its full genome and confirmed the existence of eukaryote-like genes. They also observed that the microbe usually grows in tandem with a second, methane-producing archaeon, with whom it fosters a SYMBIOTIC RELATIONSHIP. Prometheoarchaeum breaks down amino acids and supplies its partner with energy in the form of hydrogen, which might otherwise impede the Asgard’s growth, according to Science.
Images captured with an electron microscope revealed that Prometheoarchaeum develops lengthy appendages with multiple branches, according to Nature. The microbe may have used the tentacles to grab hold of oxygen-producing organisms.
Streptococcus pneumoniae strains colonizing the Nasopharynx use Quorum Sensing and Fratricide to outcompete
ReplyDeleteincoming strains, thereby retaining ownership of the host. This occurs via activation of the competence regulon,
induction of lytic proteins, and turning the invader into a source of DNA for genetic exchange.
Resident pneumococci repel incoming competitors. S. pneumoniae colonizing a naïve host’s
nasopharyngeal mucosa secretes the quorum-sensing peptide pheromone CSP. At a sufficient level of
CSP, quorum signalling via ComDE induces genetic competence and the secretion of lytic proteins CbpD
and CibAB. CbpD and CibAB can then lyse incoming pneumococci, which lack expression of cognate
immunity factors. This may also provide donor DNA for uptake by the resident strain and extracellular
DNA to promote biofilm formation.
IS LIFE of MICROORGANISM POSSIBLE in the SPACE?
ReplyDeletethere is some precedent for certain creatures being able to survive the vacuum of space. Tardigrades, water-dwelling microscopic invertebrates, are known to be able to survive a host of harsh environments. They can survive extreme temperatures (slightly above absolute zero to far above boiling), amounts of radiation hundreds of times higher than the lethal dose for a human, pressure around six times more than found in the deepest parts of the ocean, and the vacuum of space. The organisms found on the ISS( international space station) aren’t tardigrades, but the little invertebrates show that some living organisms from Earth can indeed survive the harshness of space.
scientists just Found a Completely New Kind of SYMBIOTIC RELATIONSHIP Between
ReplyDelete"SALAMANDER" AND "ALGA"
the green alga "Oophila amblystomatis" makes its home inside of cells located across the body of the spotted salamander "Ambystoma maculatum".
Back in the late 19th century, biologists learned that green algae grows in the egg cases of spotted salamanders, providing a win-win situation for both; the embryos produce nitrogen-rich waste for the algae, and in turn, the algae increases the oxygen content found in the fluid around the breathing embryos through photosynthesis. For well over a century, scientists had assumed that this mutually-beneficial arrangement only occurred between the salamander embryo and the algae living outside it.
But it is found in matured salamander and alga too.
There are several possiblities for symbiotic relation ,
1) First
relationship protects the salamander from pathogens. The salamanders allow the green algae to enter their tissues and cells, but the salamander’s immune response may actually block more harmful pathogens from doing the same. The arrangement could offer salamanders protection once they hatch into the more hostile environment of the pond. “This would be something like a ‘defensive symbiosis,’ which is only theoretical at this point,” said Burns.
2) second
It’s also possible that the green algae—despite having to use fermentation to produce energy—is benefitting the salamander cells by producing nutrients, albeit fewer than they would normally produce under high oxygen conditions. “Also, though photosynthesis seems to be tuned down, it is still active and may be aiding the alga to use some energy from the sun through modified pathways,” said Burns. Which, if true, would be really cool—it means the amphibian is indirectly benefiting from photosynthesis in a manner similar to how coral does.
why bod test for 5 days
ReplyDeleteOne of the reasons to use incubation period of 5 days for BOD determination is to eliminate oxygen demand for nitrification (Due to low growth rate of nitrifying bacteria. the nitrogenous BOD demand normally occurs from 6 to 10 days) and to find out only carbonaceous oxygen demand (BOD5/BODu = 0.68)
1)nitrogen fixation is aneaerobic or aerobic?
ReplyDelete-it"s a aerobice
2)inoculation loop diameter ~5mm
volumne transfer -10 μL
lowest and highest temperature life can survive. [ -20°C to 130 °C.(Pyrolobus fumarii)].
ReplyDeletelowest and highest PH life can survive. [ PH2 to PH10]
latest study on insect microbe symbiosis involves beewolf digger wasps(philanthus spp. Hymenoptera) in association with actinobacteria
ReplyDeleteIn this, the beewolf digger females carrying actinobacteria in unique antennal glands apply the symbionts to the brood cells prior to depostion,this defends the developing wasp larvae from pathogenic fungi and bacteria.Thus,leading to vastly improved odds of survival.
Sir once you asked us that why do the culture look turbid to us?
ReplyDeleteThe answer to this question is that the cell scatter light that falls on it. The turbidity is directly proportional to the number of cells. Higher the number of cells ,higher will be the scattering of light and higher amount of light reaches our eyes, hence it looks turbid to us.
hok system
ReplyDeletehok system is a post-segregational killing mechanism employed by R1 plasmid in e. coli.
hok system involves 3 genes :1) hok :host killing
2) sok: suppression of killing
3)mok: modulation of killing.
hok system genes codes for 52 amino acid toxic protein that causes death by depolarization of cell membrane. It works in similar way to holin protein that are provided by bacteriophage before cell lysis.
Preservation of microbial cultures.
ReplyDeleteA surprising success has been reported (Boeswinkel, 1976 ; Marx and Daniel, 1976) for storage of fungus cultures in water.
Steps involved in this simple method are as follows :
1)The fungus is grown on weak medium in petri plate and then cut into small pieces.
2) By using sterile technique the pieces are transfered to sterile distilled water in small screw capped bottles.
3) The cap is screwed down.
4)The cultures are stored, preferably at low temperature.
Other methods also include : storage of spores in sand, drying cultures on filter paper and sealing tubes with paraffin wax.
Clay-Humus-Microbe Interaction:
ReplyDeleteClay mineral (and humic substances) affects the activity, ecology and population of microorganisms in soil. Clays modify the physicochemical environment of the microbes which either enhance or attenuate the growth of individual microbial population.
After release from clays, the organic material is either degraded by microorganisms or again bind to clays. Microorganisms have a negative charge at the pH of most microbial habitats. The magnitude of electronegativity on cell walls of bacteria and fungi is regulated by pH, amino acid residues and changes in wall composition.
Effect of attachment of bacteria to chemostat walls in a microbial predator - prey relationship
ReplyDeleteMixed cultures of the protozoan Tetrahymena pyriformis and the bacterium Escherichia coli were propagated in chemostats fed with glucose and minimal mineral salts medium. The interior surfaces of some chemostats were treated with a silicone compound but those of other chemostats were not. Data obtained showed that bacteria but not protozoans were attached strongly to the walls of the chemostats, that silicone treatment reduced the density of the attached bacteria by two orders of magnitude or more, and that the presence of the attached bacteria had significant effects on the dynamics of the microbial predator-prey system. Attempts were made to simulate the data by various mathematical models. It was found that a model based on combination of the Topiwala-Hamer model for wall attachment and a multiple saturation model for growth of the protozoans on the bacteria gave a reasonable fit of all data.
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ReplyDeleteResource ratio theory:
ReplyDeleteThe R* rule (also called the resource-ratio hypothesis) is a hypothesis in community ecology that attempts to predict which species will become dominant as the result of competition for resources.The hypothesis was formulated by American ecologist David Tilman.It predicts that if multiple species are competing for a single limiting resource, then whichever species can survive at the lowest equilibrium resource level (i.e., the R*) can outcompete all other species.If two species are competing for two resources, then coexistence is only possible if each species has a lower R* on one of the resource
Psychrophiles are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from −20 °C to +10 °C. They are found in places that are permanently cold, such as the polar regions and the deep sea. They can be contrasted with thermophiles, which are organisms that thrive at unusually high temperatures.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteAmensalism:
ReplyDeleteAmensalism is any biological interaction between organisms of different species in which one organism is inhibited to grow or destroyed while the other organism remains unaffected.
Antibiosis is a type of amensalism.
In antibiosis, one organism secretes a chemical that kills the other organism, while the one that secreted the chemical is unharmed.
Example of antibiosis:
Penicillium secretes penicillin which kills bacteria. the bread mold Penicillium and black walnut trees. You probably do not like to think about it, but many types of bacteria and fungi are perfectly capable of growing on bread under the right conditions. The bread mold Penicillium commonly grows on any bread that has passed its shelf life. This mold is capable of producing penicillin, which destroys many of the forms of bacteria that would also like to grow on this bread. It is the understanding of the bacteria killing properties of penicillin that led to the use of it as an antibiotic medicine. The penicillium does not benefit from the death of the other bacteria, making this an example of antibiosis.
Relation executing process of antagonism, Allelopathy.
ReplyDeleteAllelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the germination, growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial (positive allelopathy) or detrimental (negative allelopathy) effects on the target organisms and the community. Allelochemicals are a subset of secondary metabolites,which are not required for metabolism (i.e. growth, development and reproduction) of the allelopathic organism. Allelochemicals with negative allelopathic effects are an important part of plant defense against herbivory.
The production of allelochemicals are affected by biotic factors such as nutrients available, and abiotic factors such as temperature and pH.
Allelopathy is characteristic of certain plants, algae, bacteria, coral, and fungi. Allelopathic interactions are an important factor in determining species distribution and abundance within plant communities, and are also thought to be important in the success of many invasive plants.
Some species may produce more than one allelochemical; for example, three different phyotoxins, geldanamycin, nigericin, and hydanthocidin, were isolated from Streptomyces hygroscopicus. Efforts to introduce naturally produced allelochemicals as plant growth-regulating agents in agriculture have yielded two commercial herbicides, phosphinothricin, a product of Streptomyces viridochromogenes, and bialaphos from S. hygroscopicus.
ReplyDeleteWhat are Bacteriocins?
ReplyDeleteBacteriocins are proteinaceous or peptidic toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strais. They are similar to yeast and paramecium killing factors, and are structurally, functionally, and ecologically diverse.
Phytoplankton-zooplankton:
ReplyDeletephytoplankton are photosynthetic organisms, including algae, blue-green algae or cyanobacteria while Zooplankton include protozoans such as foraminiferans, radiolarians, and non-photosynthesizing dinoflagellates as well as animals like tiny fish and crustaceans such as krill.
As phytoplankton are plants, they obtain their energy through the conversion of sunlight in photosynthesis and pull nutrients from the water around them.
Zooplankton generally feed upon other plankton, including phytoplankton and zooplankton, along with bacteria and various types of particulate plant matter.
So, Phytoplankton are the primary food source for the zooplankton.
But, In severe cases, the massive overgrowth of the phytoplankton such as algae can release sufficient toxins to cause a die-off of fish and marine animals in the area, creating what is known as a dead zone in the water. That known as harmful algae blooms.
Amensalism (Antibiosis and Lysis):
ReplyDeleteAmensalism is the phenomenon where one microbial species is adversely affected by the other species, whereas the other species is unaffected by the first one. Generally, amensalism is accomplished by secretion of inhibitory substances such as antibiotics, etc.
Antibiosis is a situation where the metabolites secreted by organism A inhibits the organism B, but the organism A is unaffected .
Metabolites penetrate the cell wall and inhibit its activity by chemical toxicity. Generally, antimicrobial metabolites produced by microorganisms are antibiotics, siderophores, enzymes, etc. The potent antagonists e.g. Trichoderma harzianum and T. viride are known to secrete cell wall lysing enzymes, β-1, 3-glucanase, chitinase, etc. Lysis of fungal mycelium occurs due to secretion of enzymes.
Microbe - Animal interaction:
ReplyDeleteEndosymbiosis of Bacteria and Fungi with Birds and Insects:
Moreover, there is a group of birds belonging to the genus Indicator which are commonly known as honey guides. These birds are found in Africa and also in India. These birds eat upon remnants of exposed honey comb but cannot digest bees wax. Therefore, they harbour in their intestine the two microbes. Micrococcus cerolyticus and Candida albicans for carrying out the digestion of bees wax.
Except carnivorous insects, the others that live upon blood or plant sap develop symbiotic association with bacteria such as coryneforms and Gram-negative rods, and Nocardia (a member of actinomycetes). These microsymbiont are present in insect hosts in specialised cells.
The cells that contain fungi are called mycetocytes, and those that contain bacteria are called bacteriocytes. These microsymbionts provide to the insects with some growth factors (that are lacking in insects) and some essential amino acids. Also the microsymbionts assist in breakdown of certain waste products
What is chromatophore?
ReplyDeleteChromatophore is a coloured, membrane-associated vesicle used to perform photosynthesis and contain different coloured pigments.
Chromatophores contain bacteriochlorophyll pigments and carotenoids. In purple bacteria, such as Rhodospirillum rubrum, the light-harvesting proteins are intrinsic to the chromatophore membranes.
However, in green sulfur bacteria, they are arranged in specialised antenna complexes called chlorosomes.
Chromatophores are responsible for absorption of light in bacteria.
What are biofilm?
ReplyDeleteBiofilms are a collection of one or more types of microorganisms that can grow on many different surfaces. Microorganisms that form biofilms include bacteria, fungi and protists.
One common example of a biofilm is dental plaque, a slimy buildup of bacteria that forms on the surfaces of teeth. Pond scum is another example. Biofilms have been found growing on minerals and metals. They have been found underwater, underground and above the ground. They can grow on plant tissues and animal tissues, and on implanted medical devices such as catheters and pacemakers.
It can be said that, for surviving bacteria uses this (biofilm) stratergy.
Sir, once in class you asked what is chromogenic media?
ReplyDeleteChromogenic Media are culture medium used to isolate, identify, and differentiate specific microorganism from a heterogeneous population. The medium contains chromogenic substrate which is utilized by the microorganism to give colored colonies that is specific for each microorganism. Depending on the color of the result, the presence or absence of target organism is determined and also accurately differentiated from others.
Principle of Chromogenic media are based on enzymatic utilization of chromogenic substrates.
Principle of Chromogenic Media:
Chromogenic media contains soluble colorless molecules called chromogens. Chromogens are composed of two parts: a substrate ( which is the target of a specific enzymatic activity of the microorganism) and a chromophore.
When the bond between the substrate and chromophore is split by a specific enzyme produced by the target microorganism, chromophore is released. In its unconjugated form, the chromophore shows distinctive colour. Due to reduced solubility, chromophore forms a precipitate that imparts unique color to the colony.
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ReplyDeleteWhat parameters will we change for a violet color bacteria in the growth kinetics experiment?
ReplyDeleteIn an actual sense, there won't be any change needed in the setting up of parameters in the experiment, as the coloured bacteria will have the same growth kinetics like an uncoloured bacteria. The violet bacteria will have the lag phase, log (exponential) phase, stationary phase and decline phase, just as any normal bacteria will have. The only adjustment that will be need in such cases is the change in the wavelength depending upon the colour. The violet bacteria will not absorb violet hence that is transmitted making it look violet. Hence the violet bacteria will absorb in the wavelength that is complementary to it. The complementary colour to violet is yellow, hence it will absorb in the yellow colour wavelength that is 570nm. So the only thing that will change will be the wavelength for taking the Optical Density which will be 570nm instead of 625nm.
Psychrophiles and Psychotrophs.
ReplyDeletePsychrophiles are organisms that are capable of growth and reproduction in low temperatures, ranging from −20 °C to +10 °C. They are found in places that are permanently cold, such as the polar regions and the deep sea, icebergs, etc. They need cold temperatures to survive. Without such low temperatures they cannot exist or will die.
Psychrotrophs are cold-tolerant bacteria that have the ability to grow at low temperatures, but have optimal growth temperatures above 15 and 20°C. These bacteria can grow in cold temperatures but do not need cold temperatures to exist. They can grow in a range of temperatures and can also be Mesophilic in nature.
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ReplyDeleteWhat happens if all microbes were removed from the earth?
ReplyDeleteLouis Pasteur once said ,"Life would not long remain possible in the absence of micobes."
Microorganisms are the oldest inhabitants of the Earth. They have been here since 3.6 billion years ago.
If there were no microbes, there would have not been any evolution and hence no variations and no different types of life forms on Earth.
What if in present time there were no microorganisms present:
1] The level of oxygen in the atmosphere would get depleted. As, phyto-planktons produce 50% of oxygen in the atmosphere.
2] The decomposition of the dead plants,animals and other matters will not be possible.
3] The plants would not be able to perform photosynthesis which will cause a imbalance the environment.
4] The human gut bacteria will not exist hence the essential vitamins produced by such bacteria, needed by the human will not be present. Hence that will lead to severe deficiencies.
5] The world population will increase to a point that the earth will be out of the resources and soon it will be inhabitable, due to depletion of all the natural resources because of increasing demand of food.
Soon humans would perish so will the other living organisms. Hence it is impossible to imagine a life without microorganisms.
What will happen if all microbes are removed from the earth?
ReplyDelete1)Naturally all infectious diseases would vanish.
No Ebola,No common colds,No yeast infections,etc.
This may seem like the best thing ever to happen to humans, but eventually , the loss of microbes would have direct consequences for humans, animals, plants, and the environment .
2)Most nutrients would stop being made or cycled
Life depends upon the constant cycling and recycling of the basic elements of life.
For example,plants survives via photosynthesis on water (hydrogen and oxygen), sunlight (to convert water and carbon dioxide into sugar), and a host of other elements like nitrogen, phosphorous, and potassium. All of these basic chemicals are taken in from the environment and recycled back to the Earth after they're consumed.
As Bacteria, for example, convert nitrogen and carbon dioxide from the air into usable components that plants and animals can use as essential building blocks.
A loss of all microbes would be terrible news for living organisms as we can't create or take in these essential nutrients on our own.
3)Waste would accumulate.
If there aren't any microbes to break down complex compounds into their usable components, all of the unhealthy things is going to build up.
Human and animal waste, for instance, is normally taken up by bacteria and cycled back into the environment.All plants would die.
As we've learned, plants are reliant upon bacteria to survive.If they don't have microbes to take in and convert important chemical compounds into usable parts, they'll rapidly lose to ability to produce fuel via photosynthesis and will quickly die.
4)All ruminant animals — like cows, sheep, and goats would starve.Ruminant animals can't digest cellulose, the main compound that makes up plant cell walls, on their own. They rely on gut microbes that can break down cellulose, allowing the animal to digest and absorb the nutrients from the plant.
A loss of microbes would mean that they'd starve
And this assumes that there are plants to eat in the first place. Again, a loss of microbes entirely would mean that there would be no plants for them to eat at all.
Humans and other life would survive in the short term, but eventually would die.
In the end, we could survive for a period of time without microbes, but not our whole life.
Sir , once you asked, Why decline phase has decreased O. D value?
ReplyDeleteThe answe to this question is , In death phase, number of dead cells are more than number of live cells, These dead cell undergo cell lysis and then cells contents precipitate and do not continue suspended as cell suspension and OD measure basically absorbance of suspended cell, this in turn decrease OD
Why most of microorganisms resides in large intestine ?
ReplyDeleteAnswer to this question is , many bacteria that inhabit the large intestine can further digest some material, creating gas. Bacteria in the large intestine also make some important substances, such as vitamin K, which plays an important role in blood clotting. These bacteria are necessary for healthy intestinal function.
What is ideal depth of butt in agar slant?
ReplyDeleteIdeal depth of butt in agar slant is 1 inch deep.
Rumen fermentation:
ReplyDeleteRumen fermentation is a process that converts ingested feed into energy sources for the host. Fiber scratches the rumen wall to start a series of contractions. These contractions lead to rumination, which is the process that physically breaks down the fiber source. Feed is then regurgitated, chewed and swallowed usually 50 to 70 times during rumination before passing through the next compartment of the stomach.
Microbial populations ferment feed and water into volatile fatty acids and gases (methane and carbon dioxide). When fermentable carbohydrate in the diet is digested too rapidly, the bacteria will increase the production of both volatile fatty acids and lactic acid. To sustain growth and the activity of fibrolytic microbes, it is crucial to maintain ruminal pH above 5.8, which will prevent the decline of fiber digestion and subsequent problems.
What is Coevolution?
ReplyDeleteCoevolution involves reciprocal adaptive changes that occur among interdependent species.
Antagonistic relationships, mutualistic relationships, and commensalistic relationships in communities promote coevolution.
Coevolutionary antagonistic interactions are observed in predator-prey and host-parasite relationships.
Coevolutionary mutualistic interactions involve the development of mutually beneficial relationships between species.
Coevolutionary commensalistic interactions include relationships where one species benefits while the other is not harmed. Batesian mimicry is one such example
QUESTION:What would happen if there were no microorganisms?
ReplyDeleteIf there were no microorganisms on the Earth then there would be no life as we understand it because evolution from a common microscopic ancestor could not have happened. As we all know that multicellular organisms evolved from unicellular organisms so if there were no unicellular organism than possibly there will be no existence of multicellular organism.
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ReplyDeleteThis comment has been removed by the author.
ReplyDeleteQUESTION:What would happen if microorganisms suddenly get disappear?
ReplyDeleteIf all microbes disappeared we'd get to enjoy life without microbial disease this sounds good and humans, oddly, would be fine. Unlike other animals,for whom sterility would mean a quick death we would get by for weeks, months, even years. now another part which is so bad. All photosynthesis would likely cease. Bacteria are vital in keeping nitrogen cycling through the ecosystem, and nitrogen is vital to plant growth. We'd need to come up with some artificial way of releasing nitrogen from dead organisms and redistributing it, or the planet would slowly starve. Along with other grazing mammals, our livestock would perish. Without bacteria around to break down biological waste, it would build up. And dead organisms wouldn't return their nutrients back to the system. phytoplankton,responsible for producing an estimated 80% of the world's oxygen, so there will be less oxygen to breath. Annihilation of most humans and non microscopic life on the planet would follow a prolonged period of starvation, disease,and global biogeochemical asphyxiation.
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ReplyDeleteQUESTION:Symbiotic association found in 2019?
ReplyDeleteBeetles (Coleoptera) have the highest species diversity among all orders, and they have diverse food habits. Gut microbes may have contributed to this diversification of food habits. Scientists identified the pattern of the relationship between ground-dwelling beetles and their gut microbial communities (bacteria and fungi) in the field. Scientists collected 46 beetle species of five families from secondary deciduous forests and grasslands in Japan and extracted microbial DNA from whole guts for amplicon sequencing. The gut bacterial and fungal communities differed among all habitats and all food habits of their hosts (carnivores, herbivores, omnivores, and scavengers) except for the fungal communities between carnivores and scavengers. Specifically, the abundant bacterial group varied among food habits: Xanthomonadaceae were abundant in scavengers, whereas Enterobacteriaceae were abundant in carnivores and herbivores. Phylogenetically closely related beetles had phylogenetically similar communities of Enterobacteriaceae, suggesting that the community structure of this family is related to the evolutionary change in beetle ecology. One of the fungal groups, Yarrowia species, which has been reported to have a symbiotic relationship with silphid beetles, was also detected from various carnivorous beetles.
Ectosymbiotic bacteria at the origin of magnetoreception in a marine protist:
ReplyDeleteMutualistic symbioses are often a source of evolutionary innovation and drivers of biological diversification. They are widely distributed in the microbial world, particularly in anoxic settings, they often rely on metabolic exchanges and syntrophy. Here, it was reported that a mutualistic symbiosis observed in marine anoxic sediments between excavate protists (Symbiontida, Euglenozoa)and ectosymbiotic Deltaproteobacteria biomineralizing ferrimagnetic nanoparticles. Light and electron microscopy observations as well as genomic data support a multi-layered mutualism based on collective magnetotactic motility with division of labour and interspecies hydrogen-transfer-based syntrophy. The guided motility of the consortia along the geomagnetic field is allowed by the magnetic moment of the non-motile ectosymbiotic bacteria combined with the protist motor activity, which is a unique example of eukaryotic magnetoreception acquired by symbiosis. The nearly complete deltaproteobacterial genome assembled from a single consortium contains a full magnetosome gene set, but shows signs of reduction, with the probable loss of flagellar genes. Based on the metabolic gene content, the ectosymbiotic bacteria are anaerobic sulfate-reducing chemolithoautotrophs that likely reduce sulfate with hydrogen produced by hydrogenosome-like organelles underlying the plasma membrane of the protist. In addition to being necessary hydrogen sinks, ectosymbionts may provide organics to the protist by diffusion and predation, as shown by magnetosome-containing digestive vacuoles. Phylogenetic analyses of 16S and 18S ribosomal RNA genes from magnetotactic consortia in marine sediments across the Northern and Southern hemispheres indicate a host–ectosymbiont specificity and co-evolution. This suggests a historical acquisition of magnetoreception by a euglenozoan ancestor from Deltaproteobacteria followed by subsequent diversification. It also supports the cosmopolitan nature of this type of symbiosis in marine anoxic sediments.
Why is it important to study archaea?
ReplyDeleteThey contribute to global nutrient cycle. Help in understanding evolution better as they are at the root of phylogenetic tree. They are the major routes for ammonium oxidation. Also serve as novel commercial organisms, eg. Production of thermostable polymerases. Ammonia oxidizing archaea(AOA) - found abundant in oceans, soils and salt marshes. Only one AOA pure cultures could be made till today - that of Nitrosopumilus maritimus. AOA have greatly outnumber AOB(Ammonia Oxidizing Bacteria) in many common environments. Ether linked lipids from Archaea- possible adjuvants in antigen delivery but still not been used in commercial vaccine production. It is believed that archaea in mutualistic relationships may provide health benefits also.
Viruses of Archaea.
ReplyDelete1.In hypersaline environments, haloarchaea (halophilic members of the Archaea) are the dominant organisms, and the viruses that infect them, haloarchaeoviruses are at least ten times more abundant. Since their discovery in 1974, described haloarchaeoviruses include head-tailed, pleomorphic, spherical and spindle-shaped morphologies, representing Myoviridae, Siphoviridae, Podoviridae, Pleolipoviridae, Sphaerolipoviridae and Fuselloviridae families.
2.new virus of hyperthermophilic archaea, Sulfolobus polyhedral virus 1 (SPV1), which condenses its circular double-stranded DNA genome in a manner not previously observed for other known viruses.
Why is it important to study archaea ..!!??
ReplyDeleteThe most significant role that the procaryotes (eubacteria and archaea) play in the ecosystem is that they recycle the essential elements and regulate the bigeochemical processes. In mesophilic environment, a large group of archaea are ammonia oxidisers.. ... Archaea are also involved in anaerobic methane oxidation.
So far, most archaea are known to be beneficial rather than harmful to human health. They may be important for reducing skin pH or keeping it at low levels, and lower pH is associated with lower susceptibility to infections.
What are the benefits to microbes living in biofilms?
ReplyDeleteBiofilm is a strong and dynamic structure that confers a broad range of advantages to its members, such as adhesion/cohesion capabilities, mechanical properties, nutritional sources, metabolite exchange platform, cellular communication, protection and resistance to drugs (e.g., antimicrobials, antiseptics, and disinfectants), environmental stresses (e.g., dehydration and ultraviolet light), host immune attacks (e.g., antibodies, complement system, antimicrobial peptides, and phagocytes), and shear forces.
What would have happen if the Microorganism suddenly disappear ?
ReplyDeleteThe answer to this can have merits and demerits first going with the merits if the microorganism disappears than there will be no human and microbe interaction which will decrease the mortality rate and no person will die out of disease except autoimmune diseases . There be will no contamination of things kept open 3. No use of medicines and antibiotics. Now coming into to Demerits 1. As population rate will increase due to no death 2. Fossils wont be available 3. Economy will get affected due to no fermentation industry and dairy industry will come to an end . Drugs manufacturing companies will perhaps be at the verge 4. The helpful microbes present inside the body wont be there so metabolism will be affected...
What's the ecological role of phyto planktons?
ReplyDeletePhytoplankton are major primary producers in the aquatic realm, responsible for almost half of global net primary production (Field et al. 1998). Their abundance and community structure directly impact higher trophic levels and key biogeochemical cycles. Phytoplankton are an extremely diverse, polyphyletic group that includes both prokaryotic and eukaryotic forms. What makes phytoplankton so successful? Several fundamental processes, such as photosynthesis, growth, resource acquisition, and grazer avoidance, to a large degree define ecological niche of phytoplankton. The success of phytoplankton depends on how efficiently they acquire resources, transform them into growth, and avoid being eaten or infected. Diverse selective pressures on phytoplankton increase the efficiency of these processes and allow species to persist under changing conditions. Resource competition is one of the key ecological processes that controls species composition, diversity, and succession of phytoplankton communities. In this chapter I discuss the role of resource competition in structuring past, present, and future phytoplankton communities.
QUESTION:Why is it important to study archaea?
ReplyDeleteStudies of archaea have proven to be enormously fruitful: unique traits found nowhere else in nature have been revealed in archaea, and there are many instances of archaeal processes that combine a mosaic of bacterial and eukaryal features with unique archaeal ones to create a third functioning mechanism. Archaea are useful model systems for processes in both eukarya and bacteria, and their major roles in various ecosystems, not just extremophilic ones, continue to be uncovered. They have useful biotechnology/ commercial applications, and may yet prove to affect human health in significant ways. There is continued study and debate about their role in evolution and, due to their ability to thrive at the limits of life on Earth, the possible presence of organisms that resemble the archaea in extraterrestrial environments. Archaea have some unique feature like Ether-linked lipids, Unique cell envelopes, Novel surface appendages, New virus families, ssrRNA signatures, tRNA modifications, Ribosome structure, Ribosome composition, Antibiotic sensitivity pattern, RNA polymerase composition, Growth above 100 degree Celsius, Methanogenesis and unique coenzymes, Sulfur-oxidizing pathways, Hyperthermophilic nitrogen fixation, Ammonia oxidation mechanism, Lipoylation, Modified sugar-degrading pathways.
what is reverse electron flow and why it is necessary?
ReplyDeleteFe+3, SO32-, NO31-etc are chemolithotrophs bacteria. they have a redox potential too positive to reduce NAD+. In reverse electron flow Delta mu H+ (transmembrane electrochemical proton potential ) is used to drive the transfer of electron from an electron donor with more positive redox potential to an acceptor with more negative redox potential. In other words,Delta mu H+ is driving force for this process. reverse electron flow has to occure whenever the redox potential of the electron donor too positive to reduce NAD+ to NADH. the energy consumed in reverse electron transport is five times greater than energy gained from the forward process.
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ReplyDeleteThis comment has been removed by the author.
DeleteQuestion: how to cultivate extremophiles: there are some specialized bioreactors which are made which has high temperature and greatly elevated.
ReplyDeletepressure.https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.clarklab.org/research/extremophiles&ved=2ahUKEwjZt8XPrY7lAhXDpY8KHZ1pB4YQFjARegQICBAB&usg=AOvVaw2LsNPRVOmiQCK9s7En0ZLi&cshid=1570596601543
Given link has a brief content to cultivation of extremophiles and the picture of the specialized bioreactor in which cultivation occurs. 19mbt042 malhar thakar
Key difference between archae and bacteria :
ReplyDelete1) Like the bacteria, archaea are single-cell, simple prokaryotes, lacking the well-defined nucleus and other organelles. Archaea are capable of surviving under the extreme condition and so are considered as extremophiles.
2)Archaea are found in the unusual environment like in hot spring, ocean depth, salt brines, while bacteria are found everywhere like in the soil, water, living and non-living organisms.
3)The cell wall of archaea is pseudopeptidoglycan, as they have ether bonds with the branching of aliphatic acids, whereas bacteria have lipid membrane ester bonds with fatty acids.
4)Archaea exactly do not follow glycolysis or Kreb cycle but uses similar pathway, but bacteria follows these pathways to produce energy.
5)Methanogens, Halophiles, Thermoacidophiles are the type of archaea, while gram positive and gram negative are the types of bacteria.
6)Archaea reproduce asexually by binary fission, fragmentation, or by the budding process, on the other hand, bacteria can produce spores which allow them to live in unfavourable condition and they divide sexually as well as asexually.
7)In archaea features like thymine is absent in the tRNA (transferase RNA) and introns are present, whereas in bacteria thymine is present in the tRNA and introns are absent.
8)In archaea, the RNA polymerase is complex and contains ten subunits, while in RNA polymerase in bacteria is simple and contains four subunits.
9)Pyrolobus fumarii, Sulfolobus acidocaldarius, Pyrococcus furiosus, Methanobacterium formicum are few examples of archaea. Streptococcus pneumoniae, Yersinia pestis, Escherichia coli (E.coli), Salmonella enterica, are the examples of bacteria.
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ReplyDeleteCultivation of extremophiles:
ReplyDeleteThere are exploitation of microorganisms isolated from extreme environments, e.g., deep-sea hydrothermal vents. These versatile organisms, so-called extremophiles, are able to grow and survive in harsh environments and should thus be useful under a broad range of process conditions. Many believe such organisms are also the progenitors of all other organisms and may thus hold clues into the origins of life. For this research, specialized apparatus were constructed that can duplicate the most extreme conditions on Earth known to support life, i.e., high temperatures and greatly elevated pressures. By studying extremophiles under these conditions, it was able to examine mechanisms by which these robust organisms adapt to stressful extremes and explore new bioprocesses at the outer limits of life.
QUESTION:Why visible photometry is a useful method for bacterial growth quantification despite non pigmented bacterial cells not absorbing much in visible spectrum?
ReplyDeleteOD is not mere an absorption. Cells of many bacteria are colourless and light absorption by them is marginal. Strongly pigmented cells such as phototropic bacteria significantly absorb light in addition to scattering. The principle of photometric analysis is scattering which is only observed in non pigmented cells.
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ReplyDeleteQUESTION :Why is it important to study archaea?
ReplyDeleteANSWER :unique traits found nowhere else in nature have
been revealed in archaea, and there are many instances of
archaeal processes that combine a mosaic of bacterial and
eukaryal features with unique archaeal ones to create a third functioning mechanism.
- Archaea are useful model systems for processes in both eukarya and bacteria, and their major roles in various ecosystems, not just extremophilic ones, continue to be uncovered.
-They have also useful for commercial applications, and may yet prove to affect human health in significant ways. There is continued study and debate about their role in evolution and, due to their ability to thrive at the limits of life on Earth, the possible presence of organisms that resemble the archaea in extraterrestrial environments.
so,the study of archaea is very important because of it's unique features and environmental importance.
Question:Why different microorganisms have different shape?
ReplyDeleteAnswer:Different shapes of microorganisms is an adaptation to have access to nutrition,motility, escaping predators and to fit to the particular environment.Moreover it would have been difficult for us to primarily identify them under microscope.
QUESTION:What would happen if microorganisms suddenly get disappear?
ReplyDeleteThere are pros and cons of every situation. World without microorganisms would be happy, free from all infections and diseases which may also result into population burst! We would be free from the fear of spoilage of fruits and vegetables, milk, meat, eggs etc. On the other hand,global photosynthesis would come to halt, Nitrogen fixation would cease and plants would not obtain balanced nutrition. Decomposition of organic matter into simpler substances and recycling of natural waste would be almost be impossible. Our body constitutes of 10 fold microbes than that of human cells which proves their usefulness to us in every way, in every process that is carried out in our body. They are responsible for development of immune system, digestion, production of Vitamin K , detoxification of harmful chemicals in our body. No fermentation , no sewage treatment, no production of fuels, enzymes and bioactive compounds and in almost all the fields they are useful. These earliest forms of life are omnipresent without which survival of multicellular organisms would be difficult. Best example is of Deinococcus radiodurans - world's toughest bacterium in 'The Guinness book of world records'. It is most radiation resistant organism surviving in thousand times more radiations than a human can and all other extreme conditions so they are also called as polyextremophile. These are also very useful for biomedical research, nanotechnology and bioremediation.
Why cells are different in shape?
ReplyDeleteAns:
Cells have different shapes because they do different things. Each cell type has its own role to play in helping bodies to work properly, and shapes help them carry out these roles effectively. If all the cells will be of same shape and size , it will be very difficult for multicellular animals including humans to adapt better to the environment and survive. For example Red blood cells, immune cells, Neuron cells.
Methanogens are responsible for the methane in the belches of ruminants and in the flatulence in humans. Methanogens play a vital ecological role in anaerobic environments by removing excess hydrogen and fermentation products produced by other forms of anaerobic respiration.
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ReplyDelete>Pigmentation is very useful for organism.
ReplyDelete>It is associated with morphological characteristics, cellular activities, pathogenesis, protection and survival.
>Pigmentation help to carry out photosynthesis.
Eg. Autotrophic cyanobacteria contain chlorophyll (green pigment)
> Pigmentation help to absorb UV radiation or to quench oxygen free radicals (i.e. basically help in cell protection)
> Pigmentation helps to maintain membrane integrity and stability.
> Pigmentation may act as antibiotics against phytopathogenic funi, bacteria and yeast
Eg. Spirilloxanthin from spirillum
Prodigiosis from serratia
> Pigmentation help in survival in stress conditions
Eg. Pigment produce by pseudomonas sp. Like pyoverdin and pyochelin act as siderosphor. (i.e. scavenge trace of iron.)
In Rhizosphere region, iron is present in limited amount. Rhizobacteria like pseudomonad produce iron chelating compound or siderosphor (i.e. scavenge trace of iron.)
19MBT019
ReplyDeletePigmentation is also used for microbe microbe interactions and communication for example Pyocyanin a blue pigment that is a toxin produced and secreted by the Gram negative bacterium Pseudomonas aeruginosa. Pyocyanin is a secondary metabolite with the ability to oxidise and reduce other molecules and therefore can kill microbes competing against P. aeruginosa.
ReplyDeleteQue. Why do all bacteria have different shapes?
The shape of bacteria is defined mainly according to the environment they live in or the problems they are facing in their habitat. For this we can give two types of arguments:
1. The shape of bacteria is same for any one genus which typically exhibits a limited subset of morphologies, hinting that, with a universe of shapes to choose from, individual bacteria adapt only those that are adaptive.
2. Some can modify their morphology in response to environmental cues or during the course of pathogenesis suggesting that shape is important enough to merit regulation.
Thus, from this arguments we can say that the shape of bacteria is defined by the parameters around them like availability of nutrition, motility of cell, predation activity around them, etc.
What is coevolution ..??
ReplyDeletethe influence of closely associated species on each other in their evolution.
coevolution refers to the evolution of at least two species, which occurs in a mutually dependent manner. ... An example is the coevolution of flowering plants and associated pollinators .e.g., bees, birds, and other insect species.
ReplyDeleteWhat happens if all microbes were removed from the earth?
Microbes play a central part in most of all eco systems
Microbes help in the recycles the nutrients by degrading dead plant and animals
Micro plants called phytoplanktons present in ocean produce around 50% oxygen apart from plant it also affect the animals and plants , in our body there are trillions of bacteria they helps in digestion of food and also affect the behaviour of individuals
QUESTION:Purpose of pigment production in bacteria?
ReplyDeleteDifferent bacteria can produce different colour pigments which show taxonomical significance - Pigments important for particular genus - helpful in identification and classification. Mainly bacteria produce pigments as secondary metabolites. Colour of the pigments is their secondary property while their primary properties are :- Photosynthesis - autotrophic bacteria need pigments for photosynthesis. Cell protection - Pigments produced by bacteria absorb UV radiations or form products from oxygen free radicals.Defence mechanism - pigments can also protect bacteria from virulence and protect extremophiles from oxidative stress. Multidrug resistance and heavy metal resistance - Pathogenic staphylococci are multi drug resistant because their pigments act as a barrier for antibodies acting on cell wall and plasma membrane.
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ReplyDeleteRole of pigment production in bacteria :
ReplyDeletePigments are compounds with characteristics of importance to many industries. Among microbes, bacteria have immense potential to produce diverse bioproducts and one such bioproduct is pigments.
There are many reason the bacteria to produce pigments.
1. Phototsynthesis
2. UV protection
3. Defense mechanisms
4.Secondary metabolites for storage of energy
5. Stress
It varies with environment differs in marine, terrestrial and space.
Q-what is the purpose of pigment production in bacteria?
ReplyDeleteA-Pigments have evolved in nature to serve a variety of purpose. Pigments can serve a more fundamental purpose that includes protection from oxidative stress, absorption of light in plants and retina in animals, protection from harmfull UV light.
It also play an important role in pathogenic microorganisms as pathogenecity inducer. If we remove gene which responsible for pigment production than they became harmless
Eg:- Staphylococcus aureus
It produce golden yellow pigment when pathogenic after gene removal they show nonpigmented colonies.
Some species of microbes produce pigments against environmental stress.
Eg:- Synechococcus species accumulate carotenoids in response to iron stress.
Some compound induce the color pigmentation. Methanol induce color pigmentation in Acinetobacter wofii.
Some pigments create harmfull effect on other cell. Eg:- vibrio cholera makes melanin which help to cause infection in GI track of human and survive in aquatic environments.
Pigments are secondary metabolites so it energy require process. Some of them show toxic effect on other living form of life.
Q-why do all bacteria have different shapes?
ReplyDeleteThe different shapes of bacteria is based on the morphology of bacterial cell is affected by a combination of selective pressure, access to nutrients, cell division, attachment, dispersal, predation, motility and defence mechanism.
Apart from that three factore may help to explain this secret of nature.
1)Nutrient uptake :- different shapes of cell is depend on the condition where nutrient available which may create condition that favour one bacterial shapes over another.
2)Motility:- motility imposes a heavy selective pressure on cell shape. It helps to travel from one place to another when condition became unfavourable.
3)predation:-it helps to protect itself when predator come and it helps to struggle against being eaten.
Q-why it is important to study archea?
ReplyDeleteA- Archea looks like bacteria but biochemically and genetically they distinct from bacteria and they even closer to eukaryotic counter parts rather than prokaryotic.
The metabolic pathway and enzymes which are involved they are more resemble to eukaryotic living system.
The habitat from which they are identified and isolated it helps to study the living form of life on earth at early stage of evolution and also survival of life in extreme condition.
Some archea have the genes which are not resemble to anyother living form.
Eg:- archea which survive in extreme saline condition and some molecules of archea which survive in high acidic condition.
Question:-How halophiles protect them from osmotic shock?
ReplyDeleteAnswer:-Most halophilic and all halotolerant organisms expend energy to exclude salt from their cytoplasm to avoid protein aggregation known as salting out.To survive the high salinity, halophiles employ two differing strategies to prevent desiccation through osmotic movement of water out of their cytoplasm. Both strategies work by increasing the internal osmolarity of the cell.
Why bacteria have different shapes?
ReplyDelete3 main points which defines the shape of Bacteria:
Nutrient uptake: Cell shape, in and of itself, affects nutrient acquisition and argues that other nutritional situations may create conditions that favor one bacterial shape over another.
Motility: Motility imposes a heavy selective pressure on cell shape. Fast cells are better off as rods with a certain length-to-width ratio, chemotactic cells must adopt shape ratios in line with their environments, and cells that forage near surfaces or navigate viscous environments may do best if they are slightly curved or spiral.
Predation: In their struggle against being eaten, bacteria have adopted morphological defenses that may have produced the shapes
These factors play a role in shaping bacteria.
Bacterial morphology is affected by a combination of selective pressures - access to nutrients, cell division, attachment/dispersal, predation and motility (among others). Among these different factors, our understanding of the relationship between motility and cell shape is most complete; for example, highly motile bacteria are usually rods with a specific (optimal) shape and size, and movement through viscous fluids seems to a favor spiral shape. But since multiple selective forces are always in play, there is at the moment no way to predict cell shape based on the environment or vice versa.
Adaptations to various environments could be possible but depending upon the environment we can not predict the shape of bacteria because some other factor might have played major role in giving shape to it.
Bacteria have different shapes because of three reasons
ReplyDelete1.Nutrient uptake
2.protection
3.predation
4.environmental forces
(19MMB028)
Bacteria produce pigment because of performing photosynthesis,defense mechanism,production of secondary metabolite for storage of energy.
ReplyDelete19MMB028
Question:Which virus is infects the banana?
ReplyDeleteAnswer. : Banana bunchy top virus is infect the banana. this virus is from Nanoviridae family.The genome of BBTV is made up of at least six circular, single-stranded DNA components, each about 1 kilo-base pair in length.Replication takes place by rolling circle replication, a unidirectional nucleic acid replication that can result in rapid synthesis of single-strands of DNA.Like many viruses, BBTV was named after the symptoms seen, where the infected plants are stunted and have "bunchy" leaves at the top.
Infected banana plants by BBTV are stunted and produce small, deformed fruits. In advanced stages of the disease, plants do not produce any fruit. Infected banana plants are useless and serve only as a source of the virus. A tiny insect called the banana aphid spreads the disease by carrying the virus to healthy plants after feeding on infected plants.
DeleteQuestion:Which virus is infects the honey bees?
ReplyDeleteAnswer : According to NCBI Deformed wing virus (DWV) is infects the honey bee.DWV is a single-stranded RNA virus of honey bees. transmitted by the parasitic mite Varroa destructor. Although DWV represents a major threat to honey bee health worldwide, the pathological basis of DWV infection is not well documented.
Question:purpose of pigment production in bacteria?
ReplyDeletePigment production helps in survival of bacteria and it also increases virulence of bacteria.
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ReplyDeleteThis comment has been removed by the author.
ReplyDeleteQue:- What are virusoids??
ReplyDeleteAns:- Virusoids belong to a large, group of infectious agents called satellite RNAs. They are found in bacteria, plants, fungi, invertebrates and vertebrates. They are satellite, viroid like molecules but larger than viroids. Satellite viruses encode capsid proteins but depend on a helper virus for replication, therefore, they are called ‘satellite’.
Q:-Which virus infect the honey bees?
ReplyDeleteA:-DMV- Deformed Wing Virus
DMV cause infection in honey bee(Apis mellifera). It leads major cause of elevated looses of honey bea colonies. It is SS-RNA virus. It has two widespread genotypes A and b. In adult honey bee DMV-B has been shown to be more virulent than DMV-A. The characteristics are not completely known for DMV.
Q:- Which virus cause infection in banana?
ReplyDeleteA:-BBTV-Banana Bunchy Top Virus.
It is SS-DNA virus. The virus is transmitted inapersistent circulative,non-propagative manner by the banana aphid Pentalunia nigronervosa which has worldwide distribution. It leads 70-90% loss of production in infected plant and that could not be recovered.
Domain - Virus
Group -SS-DNA viruses
Sub group -DNA viruses
Family - Nanoviridae
Genus -Babuvirus
Species -Banana Bunchy Top Virus .
banana is one of the most important staple food crops
Deleteplants which grow, mature and fruit without seasonality throughout the year.
Viral diseases are considered a major concern for banana production because
of their effects on yield and quality as well as limitations to germplasm
multiplication and the international germplasm exchange. There are many
(about 20) different viruses reported to infect banana worldwide. However,
the economically most important viruses are: Banana bunchy top virus
(BBTV), Banana streak viruses (BSV), Banana bract mosaic virus (BBrMV)
and Cucumber mosaic virus (CMV). Among these, BBTV and BSV are
major threats for banana production. Of the two, BSV exist as episomal and
endogenous forms and more widely spread worldwide than BBTV
Q:which virus can infect banana?
ReplyDeleteA:banana streak virus(BSV),Banana bract mosaic virus,Banana bunchy top virus can infect banana and cause diseases.
Question:-How calcivirus cause infection in humans and animals?
ReplyDeleteAnswer:-Caliciviral infections in humans, among the most common causes of viral-induced vomiting and diarrhea, are caused by the Norwalk group of small round structured viruses, the Sapporo caliciviruses, and the hepatitis E agent. Human caliciviruses have been resistant to in vitro cultivation, and direct study of their origins and reservoirs outside infected humans or water and foods such as shellfish contaminated with human sewage has been difficult. Modes of transmission, other than direct fecal-oral routes, are not well understood. In contrast, animal viruses found in ocean reservoirs, which make up a second calicivirus group, can be cultivated in vitro. These viruses can emerge and infect terrestrial hosts, including humans.The history of animal caliciviruses,their eventual recognition as zoonotic agents, and their potential usefulness as a predictive model for non-cultivatable human and other animal caliciviruses.
Question:-Some discovery of virus?
ReplyDeleteAnswer:- Discovery of tobacco mosaic virus in 1892 and foot-and-mouth disease virus in 1898, the first 'filterable agent' to be discovered in humans was yellow fever virus in 1901
What are virusoids?
ReplyDeletevirusoids are also infectious agents, but they differ from viruses in several ways. For instance, they have a single-stranded circular, RNA genome. Their genomes are very small and do not code for proteins. Viroids replicate autonomously inside a cell, but virusoids cannot. Rather, virusoid replication requires that the cell is also infected with a virus that supplies "helper" functions.
Which virus infects honeybees?
ReplyDeleteParasitic mite Varroa destructor transmits ssRNA virus named Deformed wing virus(DMV) which infects honey bees (Apis Mellifera L.). DWV-affected bees were 2 times slower to emerge and had 30% higher mortality compared to clinically normal bees. DMV is a major threat to honey bees all over the world yet pathological basis of this infection is not well documented . Here is the reference:-
https://www.ncbi.nlm.nih.gov/m/pubmed/30857499/
Which virus infects banana?
ReplyDeleteFour viral diseases that infects banana are banana bunchy top disease (BBTD) caused by Banana bunchy top virus (BBTV),
bract mosaic disease (BBrMD) caused by Banana bract mosaic virus (BBrMV),
banana streak disease (BSD) caused by different species of Banana streak virus (BSV),
and banana mosaic or infectious chlorosis caused by Cucumber mosaic virus (CMV), occur in most of the banana-growing regions around the world. BBTD is a century-old disease resulting into large scale crop losses all over the world but its infectivity has not yet been proven through infectious clones.
Banana bract mosaic virus (BBrMV) infects banana. The length and arrangements of different proteins in BBrMV-Cardamom was similar to other BBrMV isolates except for the P1 protein that showed a single amino acid deletion. Here are the references:-
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5014477/
https://www.sciencedirect.com/topics/immunology-and-microbiology/banana-bunchy-top-virus
QUESTION:How many viruses known till date?
ReplyDeleteThe following list represents all ICTV taxonomy releases to date. There are 14 Orders, 150 Family, 79 Subfamily, 1019 Genus, 5560 Species of viruses have been classified till date.
https://talk.ictvonline.org/taxonomy/p/taxonomy_releases
SHRUTI SOLANKI (19MBT039)
ReplyDeleteQ- Why bacteria produce pigments?
Pigments of various colors are synthesized to protect the cells of microorganisms from injurious effect of light rays of visible and near ultraviolet range. These pigments are synthesized by various types of microorganisms as
secondary metabolites and not often found in all types of organisms. Pigments come in a wide variety of colors,
some of which are water soluble. Micro-organisms which have the ability to produce pigments in high yields include species of Monascus, Paecilomyces, Serratia, Cordyceps,
Streptomyces and yellow-red and blue compounds
produced by Penicillium herquei and Penicillium
atrovenetum, Rhodotorula, Sarcina, Cryptococcus,
Monascus purpureus, Phaffia rhodozyma, Bacillus sp.,
Achromobacter, Yarrowia and Phaffia also produce a
large number of pigment2
. Microorganisms produce
various pigments like carotenoids, melanins, quinones, flavins, prodigiosins and more specifically monascins,
violacein or indigo. Some pigments produced by the bacteria shows antimicrobial activity against pathogens.
SHRUTI SOLANKI (19MBT039)
ReplyDeleteImagine the situation of Earth without microorganism.
As correctly said by Louis Pasteur ,"Life would not long remain possible in the absence of micobes."
Microorganisms are the oldest inhabitants of the Earth. They have been here since 3.6 billion years ago.
If there were no microbes, there would have not been any EVOLUTION and hence no VARIATIONS and no different types of life forms on Earth.
Talking about the present condition of Earth without microbes, survival of most Eukaryotes would be doubtful.
1) Germ free existence.
2) No biogeochemical cycling of nutrients.
Rapid exhaustion of available macronutrients and micronutrients in terrestrial and aquatic environment.
3) Fungal decomposition would become the critical link between organisms death ,decay and return of decomposed nutrients to bottom of eukaryotic food chains.
So most species on Earth would become extinct and population size would be reduced greatly for the species that endured.
4) we could digest our food as gnotobiotic animals, assimilating most of what we have consumed.
5) Imbalance in Ecosystem ,Food chain and Food web.
6) Absence of all forms of microbial disease including Ebola, Malaria, common cold, AIDS, and many more.
7) Human and animal waste would accumulate rapidly. There would be very little decomposition apart from dissociation and inherent catabolic enzymatic activity.
It will lead to Soil and Water pollution.
8) Most ruminant livestock would starve without microbial symbionts.
Plants would rapidly deplete Nitrogen, cease photosynthesis and then die. An alternative to it is to provide synthetic Nitrogen rich fertilizers. But it would lead to Global warming and pollution.
Hence, concluding that Microbes sustain life on this planet because of myriad associations and biogeochemical processes. Although life would persist in the absence of microorganisms, both the quantity and quality of life would be reduced drastically.
Question:- Uses of viruses in different field?
ReplyDeleteAnswer:-1.Viruses in biological studies
Viruses have been used extensively in molecular and cellular biology studies.Viruses have been used extensively in genetics research and understanding of the genes and DNA replication, transcription, RNA formation, translation, protein formation and basics of immunology.
2.Viruses in medicine
Viruses are being used as vectors or carriers that take the required material for treatment of a disease to various target cells. They have been studied extensively in management of inherited diseases and genetic engineering as well as cancers.
3.Viruses in weapons and biological warfare
Viruses may be tiny but have the capacity to cause death and devastation to large populations in epidemics and pandemics. This has led to the concern that viruses could be used for biological warfare.
4.Viruses and biological pest control
Viruses can also be used to control damaging pests. Traditionally this has been used in agriculture, but applications exist in the control of agents important to human health as well.
Name of the virus infecting banana and honey bee:
ReplyDeleteBanana bunchy top virus(BBTV) is a plant pathogenic single stranded DNA virus of the family Nanoviridae. BBTV causes banana bunchy top disease in banana and causes the new leaves to be stunted & "bunchy" while leaf edges are deformed & yellow.
Acute Bee Paralysis Virus (ABPV) belongs to the family of Dicistroviridae. This virus causes sudden collapse of honey bee colonies infested with the parasitic mite Varroa destructor.
Difference between facultative aerobe and facultative anaerobe:
ReplyDeleteA facultative anaerobe is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation or anaerobic respiration if oxygen is absent.
A faculitative aerobe like Lactobacillus ferment and therefore do not use oxygen, however they do tolerate it. Facultative aerobic bacteria do not require oxygen but can survive in presence of oxygen (generate ATP by aerobic respiration).
Contribution of Beijerinck in virology:
ReplyDeleteMartinus Beijerinck is considered one of the founders of virology.
He independently performed Ivanowsky's filtration experiments and then showed that the infectious agent was able to reproduce and multiply in host cells of the tobacco plant.
Beijerinck coined the term of "virus" to indicate that the casual agent of tobacco mosaic disease was of non bacterial nature.
SHRUTI SOLANKI (19MBT039)
ReplyDeleteQ- How life can survive at unusual conditions?
A- The extraordinary ability of microbial life to adapt to harsh conditions has increased the awareness of the potential value for the close study of such microorganisms. The unusual biomolecules they produce may be used as such, or modified structurally for many biological applications.
SHRUTI SOLANKI (19MBT039)
ReplyDeleteQ- What is the economical and environmental value of honeybees?
A- The Honeybees offer a key ecosystem service, essential for a sustainable productive agriculture and for the maintenance of the non-agricultural ecosystem. Pollination services are mandatory for the production of crops like fruits, nuts and fibres, whereas the results of many other agricultural crops are significantly improved by pollination. A vast number of species were found to be honeybee-pollinated plants including, high bush blueberry; apple and pears; almonds; Cantaloupe; rape varieties; and others. Honeybees were found to have a key role in increasing the seed production of three crops: broccoli, kohlrabi and Chinese cabbage. Apis mellifera is of great economic importance in terms of increased yield and quality of commercially grown insect pollinated and also assists self-pollinated crops in the world. It has been valued that without pollinators a decrease by more than 90% of the yields of some fruit, seed and nut crops could occur.
SHRUTI SOLANKI (19MBT039)
ReplyDeleteQ- Which viruses are responsible for infecting honeybees?
A- Deformed wing virus (DWV) and Kakugo virus (KV); Sacbrood virus (SBV); Black Queen cell virus (BQCV); Acute bee paralysis virus (ABPV); Kashmir bee virus (KBV); Israeli Acute Paralysis Virus (IAPV); Chronic bee paralysis virus (CBPV).
What are virusoids?
ReplyDeleteVirusoids are type of pathogenic RNA that can infect commercially important agricultural crops are the virusoids, which are subviral particles best described as non–self-replicating ssRNAs. RNA replication of virusoids is similar to that of viroids but, unlike viroids, virusoids require that the cell also be infected with a specific “helper” virus. There are currently only five described types of virusoids and their associated helper viruses. The helper viruses are all from the family of Sobemoviruses. An example of a helper virus is the subterranean clover mottle virus, which has an associated virusoid packaged inside the viral capsid. Once the helper virus enters the host cell, the virusoids are released and can be found free in plant cell cytoplasm, where they possess ribozyme activity. The helper virus undergoes typical viral replication independent of the activity of the virusoid. The virusoid genomes are small, only 220 to 388 nucleotides long. A virusoid genome does not code for any proteins, but instead serves only to replicate virusoid RNA.
Virusoids belong to a larger group of infectious agents called satellite RNAs, which are similar pathogenic RNAs found in animals. Unlike the plant virusoids, satellite RNAs may encode for proteins; however, like plant virusoids, satellite RNAs must coinfect with a helper virus to replicate. One satellite RNA that infects humans and that has been described by some scientists as a virusoid is the hepatitis delta virus (HDV), which, by some reports, is also called hepatitis delta virusoid. Much larger than a plant virusoid, HDV has a circular, ssRNA genome of 1,700 nucleotides and can direct the biosynthesis of HDV-associated proteins. The HDV helper virus is the hepatitis B virus (HBV). Coinfection with HBV and HDV results in more severe pathological changes in the liver during infection, which is how HDV was first discovered.
Viruses infecting honey bee:
ReplyDeleteDicistroviruses (Israeli acute paralysis virus (IAPV), Kashmir bee virus (KBV),
Acute bee paralysis virus (ABPV),
and Black queen cell virus (BQCV));
the Iflaviruses (Deformed wing virus (DWV),
Kakugo virus,
Varroa destructor virus-1/DWV-B,
Sacbrood virus (SBV), and
Slow bee paralysis .
Virus infecting banana:
ReplyDeleteBanana bunchy top virus (BBTV) is responsible for infecting banana. Often BBTD, banana bunchy top disease, gets its name from the bunchy appearance of infected plants. By that time, however, the virus has most likely been spread to other plants by the banana aphid, Pentalonia nigronervosa. Infected plants cannot recover and will serve as a source of viral particles unless they are destroyed. The virus is also spread through infected planting material.
Discovery of virology:
ReplyDeleteIn 1892, Dmitry Ivanovsky used one of filters to show that sap from a diseased tobacco plant remained infectious to healthy tobacco plants despite having been filtered. Martinus Beijerinck called the filtered, infectious substance a "virus" and this discovery is considered to be the beginning of virology.
Thus he , is the one who discovered viruses.
Uses of viruses in different field:
ReplyDeleteViruses in biological studies:
Viruses have been used extensively in molecular and cellular biology studies. These viruses provide the advantage of being simple systems that can be used to manipulate and investigate the functions of cells.
Viruses have been used extensively in genetics research and understanding of the genes and DNA replication, transcription, RNA formation, translation, protein formation and basics of immunology.
Viruses in medicine:
Viruses are being used as vectors or carriers that take the required material for treatment of a disease to various target cells. They have been studied extensively in management of inherited diseases and genetic engineering as well as cancers.
Viruses in bacteriophage therapy:
These are highly specific viruses that can target, infect, and (if correctly selected) destroy pathogenic bacteria. Bacteriophages are believed to be the most numerous type of viruses accounting for the majority of the viruses present on Earth. These are basic tools in molecular biology. They have been researched for their use in therapy.
Viruses in nanotechnology:
Nanotechnology deals with microscopic particles. These have various uses in biology and medicine and nanotechnology has been used in genetic engineering. Viruses can be used as carriers for genetically modified sequences of genomes to the host cells.
Viruses in weapons and biological warfare:
Viruses may be tiny but have the capacity to cause death and devastation to large populations in epidemics and pandemics. This has led to the concern that viruses could be used for biological warfare.
Q-Viruses infecting honey bee:
ReplyDeleteans-Dicistroviruses (Israeli acute paralysis virus (IAPV), Kashmir bee virus (KBV),
Acute bee paralysis virus (ABPV),
and Black queen cell virus (BQCV));
the Iflaviruses (Deformed wing virus (DWV),
Kakugo virus,
***Viruses that infect banana***
ReplyDeleteBanana bunchy top disease is the most serious virus disease of banana worldwide. Diseased plants rarely produce fruit and when they do, the fruit is stunted and twisted. However, in the rare scenario that a diseased plant does produce fruit that reaches maturity, it is edible. Banana bunchy top disease caused by a single-strand DNA virus, the banana bunchy top virus(BBTV). BBTV is the sole member of the genus Babuvirus in the family Nanoviridae. The genome of BBTV is made up of at least six circular, single-stranded DNA components, each about 1 kilo-base pair in length.
There are no resistant varieties of banana against BBTV, so the most common method of control is chemical control of the aphid vectors.The agriculture department, however, recently obtained an EPA waiver for the pesticide Provado is a means of controlling the aphids that spread the disease.
Q. Difference between Archaebacteria and Eubacteria ?
ReplyDeleteAns,
- Archaebacteria are simple in their organization where as , Eubacteria are more complex.
- Archaebacteria are Rod, Sphere, plate, spiral, flat in shape , where as Eubacteria are Cocci, bacilli, vibrio, rods, filaments or spirochetes in shape.
- Archaebacteria cell wall is composed of psuedopeptidoglycans. Whereas as, Eubacteria is composed of peptidoglycans with muriatic acid.
- Archaebacteria found in Extreme environments where as, Eubacteria found everywhere on Earth.
- Introns are Present in Archaebacteria and Absent in Eubacteria.
- Archaebacteria neither exhibit Glycolysis nor Kreb's Cycle, and there in Eubacteria both the cycles exhibit.
- Membrane lipids in Archaebacteria are Ether linked, Branched, alphabetic chains, containing D- glycerol phosphate and on the other side, Eubacteria are esters linked, straight chained fatty acid, containing L- glycerol phosphate.
- Archaebacteria has Three types-- methanogens, halophiles and thermophiles.
- Eubacteria has two types--
Gram positive and Gram negative.
EXAMPLES include--
- Archaebacteria: halobacterium, lokiarchaeum, thermoproteus, pyrobaculum, thermoplastic and ferro plasma.
- Eubacteria: mycobacteria, bacillus, sporohalobacter,clostridium and anaerobacter.
Application of viruses:-
ReplyDeleteViruses are important to the study of molecular and cell biology as they provide simple systems that can be used to manipulate and investigate the functions of cells. The study and use of viruses have provided valuable information about aspects of cell biology. For example, viruses have been useful in the study of genetics and helped our understanding of the basic mechanisms of molecular genetics, such as DNA replication, transcription, RNA processing, translation, protein transport, and immunology.
The term “the great plate count Anomaly ” was coined by Staley and Konopka in 1985 to describe the difference in orders of magnitude between the numbers of cells from natural environments that form colonies on agar media and the numbers countable by microscopic examination. Marine ecosystems are a well-studied example of this phenomenon: only 0.01 to 0.1% of oceanic marine bacterial cells produce colonies by standard plating techniques. There are numerous explanations for this anomaly. For example, species that would otherwise be “culturable” may fail to grow because their growth state in nature, such as dormancy, prevents adjustment to conditions found in the medium used for the plate counts. This hypothesis does not explain the substantial discrepancy between 16S rRNA genes recovered from seawater directly by cloning and those of the readily cultured marine taxa. Another explanation for the “great plate count anomaly” is that many of the microbial species that dominate in natural settings are not adapted for growth in media containing high concentrations of complex organic carbon. Many microorganisms may need oligotrophic or other fastidious conditions to be successfully cultured. There are many examples of microbial strains that are common in nature, but can only be cultivated by specialized techniques
ReplyDeleteWhy bacteria have different shapes ?
ReplyDeleteBecause of 3 broad considerations suggest that bacterial shapes are not accidental but are biologically important. Cells adopt uniform morphologies from among a wide variety of possibilities. Some cells modify their shape as conditions demand and morphology can be tracked through evolutionary lineages.All of these imply that shape is selectable feature that aids survival. Cell shape is driven by 8 general considerations as nutrient access,cell division and segregation, attachment to surfaces,active motility,need to escape predators,advantages of cellular differentiation and passive dispersal.Thus bacteria respond to these forces by performing a type of calculus(change),integraty over a no.of environmental and behavioral factor to produce size and shape that are optimal for circumstances in which they live.
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ReplyDeleteDifference between virus,viroids and virusoids.
ReplyDeleteViroids consist only of a short strand of circular RNA capable of self-replication.Unlike viruses, viroids do not have a protein coat to protect their genetic information.
Virusoids are subviral particles best described as non–self-replicating ssRNAs. RNA replication of virusoids is similar to that of viroids but, unlike viroids, virusoids require that the cell also has to be infected with a specific “helper” virus. Also virusoids contain protein coat unlike viroids.
Virus infecting banana:
ReplyDeleteBanana bunchy top virus (BBTV) is responsible for infecting banana. Often BBTD, banana bunchy top disease, gets its name from the bunchy appearance of infected plants.
Virus infecting honey bees include:
Dicistroviruses.
What are virusoids?
ReplyDeleteVirusoids are type of pathogenic RNA that can infect important agricultural crops , which are subviral particles best described as non–self-replicating ssRNAs. RNA replication of virusoids is similar to that of viroids but, unlike viroids, virusoids require that the cell also be infected with a specific helper virus.
Cell Shape:-
ReplyDeleteThe cell shape of bacteria depends on the cell wall composition, peptidoglycan in cell wall is a mesh of peptides and saccharides that provides rigidity and strength to the bacteria.
Also there are proteins, responsible for flipping the Lipid are believed to give cell shape, viz. FtsW, RodA, and SpoVE. FtsW is considered the main enzyme for most cell growth. RodA is found in "rod shaped bacteria" and is considered necessary for cell elongation. SpoVE is used to build the thick cell walls of bacterial spores. By controlling how Lipid is delivered to the growing cell wall, these proteins play a role in controlling cell shape and also the environmental factors do take part, but everytime that are not enough to decide the shape of bacterial cell. Thus this might be the reason to provide shape to cell and highly motile bacteria are usually rods with a specific (optimal) shape and size, while the movement through viscous fluids seems to a favor spiral shape. But since multiple selective forces are always in play, there is at the moment no way to predict cell shape based on the environment or vice versa.
Question:-Mechanism of Horizontal Gene Transfer
ReplyDeleteAnswer:-Horizontal gene transfer may occur via three main mechanisms: transformation,transduction or conjugation.
1. Transformation involves uptake of short fragments of naked DNA by naturally transformable bacteria.
2. Transduction involves transfer of DNA from one bacterium into another via bacteriophages.
3. Conjugation involves transfer of DNA via sexual pilus and requires cell –to-cell contact. DNA fragments that contain resistance genes from resistant donors can then make previously susceptible bacteria express resistance as coded by these newly acquired resistance genes.
Information of unassigned viruses from ICTV.
ReplyDeleteAccording to 9th report of ICTV(The International Committee on Taxonomy of Viruses)
Although many viruses have been classified into genera in this Report, a number of relatively well-characterized viruses are yet, for various reasons, to be assigned to existing genera/families or have been sufficiently distinguished from recognized viruses to form types and members for new genera. Some examples are listed here for which certain key characteristics are known, most notably a significant amount of sequence data along with some well-described biological and biophysical properties. There are, however, a number of viruses has been undescribed genera and families, and that underline the fact that developing a universally applicable virus taxonomy is a continuously evolving process.
Eg. Archaeal Viruses
Haloarcula phage SH1
Halorubrum pleomorphic virus 1 (HRPV-1)
Question:-Difference between splitters and lumpers
ReplyDeleteAnswer:-A "lumper" is a taxonomist who group by similar traits, assuming that differences are not as important as similarities. And place organisms which share a few major characteristics in the same group. When two named species are discovered to be of the same species, the older species name is usually retained, and the newer species name dropped, a process called synonymization or convivially, as lumping.
A "splitter" is a taxonomist who takes precise definitions, and creates new categories to classify organism on the basis of the smallest known difference, so every small difference is considered sufficient to create a new separate group. Dividing a taxon into multiple, often new, taxa is called splitting.
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ReplyDeleteWhich is the largest virus known till date?
Delete1. The biggest known viruses are Mimivirus (750 nanometer capsid, 1.2 million base pair DNA) and Mimiirus is a virus of the amoebaAcanthamoeba polyphaga and was first isolated from a cooling tower in England in 1992.
2. Megavirus (680 nanometer capsid, 1.3 million base pair DNA)
QUESTION: Which is the smallest virus known till date?Presently, PCVs are the smallest viruses found in animals. The diameter of their virions ranges from 17 to 21 nanometres in size. Their genomes consist of single-stranded DNA that is circular in nature with about 1759 (PCV1) and 1767-1768 (PCV2) nucleotides sequence.
DeleteReferences: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5366187/
Reverse Transcribing DNA Viruses
ReplyDeleteReverse transcribing DNA viruses use reverse transcriptase to replicate their genomes.Hepatitis B virus (HBV)is one of the best studied reverse transcribing DNA viruses.
HBV virions are 42 nm spherical particle that contain the viral genome. The HBV genome is a circular dsDNA molecule that consist of one complete but nicked strand and a complementary strand that has a large gap. After infecting a host cell, the viral gapped DNA is released into nucleus and gap is filled yielding a closed circular DNA. Transcription of viral genes occurs in the nucleus using host RNA polymerase and yield several mRNAs.
Which was the first animal virus discovered and had a large impact on the economy?
ReplyDeleteFoot-and-mouth disease virus(FMDV) was the first animal virus discovered in 1929 and had a significant impact on world economies and public health.
Foot-and-mouth virus cause Foot-and-mouth disease which has a broad host range that includes most hoof stock (including pigs but not horses) and several other mammalian species.
FMD virus is a single-stranded positive-sense RNA virus that belongs to the genus Aphthovirus of the Picornaviridae family. FMD virus (FMDV) is divided into seven antigenically distinct serotypes, A, O, C, Asia 1, and South African Territories (SATs) 1, 2, and 3
What virus cannot do?
ReplyDelete(1) They can't reproduce on their own. They need to infect or invade a host cell. That host cell will do all the work to duplicate the virus.
(2) They don't respond to anything. You can poke them or set up barriers, it doesn't matter. They either function or they are destroyed.
(3) They don't really have any working parts. While there some advanced viruses that seem fancy, viruses don't have any of the parts you would normally think of when you think of a cell. They have no nuclei, mitochondria, or ribosomes. Some viruses do not even have cytoplasm.
BACTERIOPHAGE THERAPY
ReplyDeleteIn an era where antibiotic-resistant bacterial infections are on the rise, phages provide numerous advantages, along with relatively few disadvantages. Today ,much more is known about bacteriophages than in the 1930s when phage therapy first appeared and began to spread to many countries. In terms of “Pros,” phages can be bactericidal, can increase in number over the course of treatment, tend to only minimally disrupt normal flora, are equally effective against antibiotic-sensitive and antibiotic-resistant bacteria, often are easily discovered, seem to be capable of disrupting bacterial biofilms, and can have low inherent toxicities. In addition to these assets, we consider aspects of phage therapy that can contribute to its safety, economics, or convenience, but in ways that are perhaps less essential to the phage potential to combat bacteria. Concerns about using phages as antibacterial agents can be distinguished into four categories: (1) Phage selection, (2) Phage host-range limitations, (3) The “uniqueness” of phages as pharmaceuticals, and (4) Unfamiliarity with phages. There are diverse ways in which phages interact with human cells. Phages can modulate innate immunity via phagocytosis and cytokine responses, but also impact adaptive immunity via effects on antibody production and effector polarization. It is thus important to consider whether phage interactions with commensal bacteria could alter community compositions in ways that impact the function of the immune system and influence the spread of pathogenic viruses, or even bacteria. So, still the discussions are going on whether bacteriophage therapy would prove useful or harmful as a treatment.
References:-
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3278648/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356784/
Discovery of Virology and Viruses:-
ReplyDelete1892 – Dimitrii Ivanovsky observed that agent of tobacco mosaic disease passes through porcelain filters that retain bacteria.
1898 – Marcus Beijerinck makes the same observation; concludes that the pathogen must be a distinctive agent.
1898 – Friedrich Loeffler and Paul Frosch (former students of Koch), find that causative agent of foot-and-mouth disease is filterable (the first animal virus).
1901 – Yellow fever virus – Walter Reed (the first human virus).
1903 – Rabies virus (Paul Remlinger, Riffat-Bay, Alfonso di Vestea).
1906 – Variola virus (Negri).
1908 – Poliovirus (Karl Landsteiner and E. Popper); chicken leukemia virus (Ellerman, Bang).
1911 – Rous sarcoma virus (Peyton Rous).
1915 – Bacteriophages -Frederik Twort, Felix D’Herelle.
1931 – Swine influenza virus (Shope).
1933 – Human influenza virus (Smith).
The name virus was coined from the Latin word meaning slimy liquid or poison. It was originally used to described any infectious agent, including the agent of tobacco mosaic disease, tobacco mosaic virus. In the early years of discovery, viruses were referred to as filterable agents. Only later was the term virus restricted to filterable agents that require a living host for propagation.
Few definitions :-
ReplyDeleteVirus - most ubiquitous entity that is infectious and is obligate intracellular parasitic organism.
Viriod - the smallest infectious pathogens known, which are composed solely of a short strand of circular, single-stranded RNA that lacks protein coating.
Virion - it is an entire virus particle consisting of an outer protein shell called a capsid and an inner core of nucleic acid (either RNA or DNA).
Prions - initially thought to be virus which replicated slowly within their host but, despite much work, no nucleic acid has been found in association with infectious materials. Aberrant forms of normal cellular proteins which can induce changes in the shape of their normal structure with catastrophic consequences for the host. In short, a prion is a type of protein that can trigger normal proteins to fold abnormally.
Prophage - The genome of Bacteriophage, when inserted and integrated into bacterial genome, which undergo to make its copies, without disrupting the cell and it is latent form so stays in the cell and divides with the division of bacterial genome.
Episome - It is the genetic material of Bacteriophage, that can replicate in absence or presence of host genome and so they can exist as independent of the main body of genetic material. DNA in some lysogenic bacteriophages act as episomes, integrating into the genome and persisting as Prophage.
Lysogen - A lysogen is a bacterial cell which can produce and transfer the ability to produce a phage.
Lysogeny - Lysogeny is characterized by integration of the bacteriophage nucleic acid into the host bacterium's genome.
It is one of the two cycles of viral reproduction.
Lysogenic conversion - In the lysogenic state the phage does not represent a significant disadvantage for the survival of the host. In fact, in contrast to the situation with latent animal viruses where no advantage for the host is known, lysogeny often carries a strong selective value for the bacterium, since temperate phages frequently confer new characteristics on the host. This phenomenon manifests itself in many ways and is referred to as lysogenic conversion.
INFECTION OF BACTERIAL AND ARCHEAEAL CELLS : LYSIS AND LYSOGENY.
ReplyDeleteThere are 2 types of phage
1.virulent phage
2.temperate phage.
Virulent phage -one that has only one option: to begin multiplying immediatley upon entering its bacterial host, followed by release from the hostby lysis. T4 is the example of virulent phage.
Temperate phages that have 2 options : upon entry into host cell, they can multiply like the virulent phages and lyse the host cell, or they can remain within host withiut destroying it. Bacteriophage lambda is an example of this type of phage.
The relation between a temperate phage and its host is called lysogeny.
The form of virus that remians within its host is called a prophage.
The infected bacteria are called lysogens or lysogenic bacteria.
Lysogenic bacteria reproduce and in most other ways appear to be perfectly normal. However, they have two distinct characteristics.
1.they can not be reinfected by same virus - that is they have immunity to superinfection.
2.they can switch from lysogenic cycle to lytic cycle.
Roll no.
19mmboo4
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ReplyDeleteQUESTION:Which was the first DNA based genome sequenced?
ReplyDeleteEnterobacteria phage phiX174 The phi X 174 (or ΦX174) bacteriophage is a single-stranded DNA (ssDNA) virus that infects Escherichia coli, and the first DNA-based genome to be sequenced.
Principles of Nomenclature of Viruses:-
ReplyDelete1. The essential principles of virus nomenclature are:
(i) to aim for stability; (ii) to avoid or reject the use of names which might cause error or confusion; (iii) to avoid the unnecessary creation of names.
2. Nomenclature of viruses is independent of other biological nomenclature. Virus taxon nomenclature is recognized as an exception in the proposed International Code of Bionomenclature (BioCode).
3. The primary purpose of naming a taxon is to supply a means of referring to the taxon, rather than to indicate the characters or history of the taxon.
4. The name of a taxon has no official status until it has been approved by the ICTV.
Reference :- https://talk.ictvonline.org/ictv1/f/general_ictv_discussions-20
QUESTION:which is the most conserved genome segments for life detection?
ReplyDeleteOn Earth, very simple but powerful methods to detect and classify broad taxa of life by the polymerase chain reaction (PCR) are now standard practice. Using DNA primers corresponding to the 16S ribosomal RNA gene, one can survey a sample from any environment for its microbial inhabitants. Due to massive meteoritic exchange between Earth and Mars (as well as other planets), a reasonable case can be made for life on Mars or other planets to be related to life on Earth. In this case, the supremely sensitive technologies used to study life on Earth, including in extreme environments, can be applied to the search for life on other planets. Though the 16S gene has become the standard for life detection on Earth, no genome comparisons have established that the ribosomal genes are, in fact, the most conserved DNA segments across the kingdoms of life. Scientists present a computational comparison of full genomes from 13 diverse organisms from the Archaea, Bacteria, and Eucarya to identify genetic sequences conserved across the widest divisions of life. Their results identify the 16S and 23S ribosomal RNA genes as well as other universally conserved nucleotide sequences in genes encoding particular classes of transfer RNAs and within the nucleotide binding domains of ABC transporters as the most conserved DNA sequence segments across phylogeny. This set of sequences defines a core set of DNA regions that have changed the least over billions of years of evolution and provides a means to identify and classify divergent life, including ancestrally related life on other planets.
References: https://www.ncbi.nlm.nih.gov/pubmed/18853276/
QUESTION: Which was the first RNA based genome sequenced?
ReplyDeleteThe first genome, that of RNA bacteriophage MS2, was sequenced in 1976.This was followed by the genome of bacteriophage ϕX174. These are some of the smallest known genomes with only four and ten genes, respectively.
Sequence comparative genomics had a real head start with two astonishing discoveries , First, it has been shown that RNA-containing retroviruses shared a conserved replicative enzyme, the reverse transcriptase, with two groups of DNA viruses, Second, it turned out that small RNA viruses infecting animals (such as polio and foot-and-mouth disease) and those infecting plants (cowpea mosaic virus) shared not only significant sequence similarity that allowed the identification of homologous genes, but also, in part, the order of these genes in their genomes.
Reference:- https://www.ncbi.nlm.nih.gov/books/NBK20263/
This comment has been removed by the author.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteQue : why is agar agar spelled twice?
ReplyDeleteThe agar agar is called twice because the word agar is derived from agar - agar which is the malay name for red alage which is known as gigartina giacilaria so it's called twice
Que: Some discovery of viruses?
ReplyDelete1892 – Dimitrii Ivanovsky observed that agent of tobacco mosaic disease passes through porcelain filters that retain bacteria
1898 – Marcus Beijerinck makes the same observation; concludes that the pathogen must be a distinctive agent
1898 – Friedrich Loeffler and Paul Frosch (former students of Koch), find that causative agent of foot-and-mouth disease is filterable (the first animal virus)
1901 – Yellow fever virus – Walter Reed (the first human virus)
1903 – Rabies virus (Remlinger, Riffat-Bay)
1906 – Variola virus (Negri)
1908 – Poliovirus (Karl Landsteiner and E. Popper); chicken leukemia virus (Ellerman, Bang)
1911 – Rous sarcoma virus (Peyton Rous)
1915 – Bacteriophages -Frederik Twort, Felix D’Herelle
1931 – Swine influenza virus (Shope)
1933 – Human influenza virus (Smith)
Que: Why study of archea is important?
ReplyDeleteArchaea though similar in shape and size to bacteria have many genes in common with eukaryotes.Also they have metabolic pathways that are similar to eukaryotic pathways.Notably closely related are the enzymes involved in trancription and translation. More studies on archaea would fill up the gaps in knowledge about eukaryotic evolution.As microbiology undergoes a renaissance, fuelled in part by developments in new sequencing
technologies, the massive diversity and abundance of microbes becomes yet more obvious. The Archaea have traditionally been perceived as a minor group of organisms forced to evolve into
environmental niches not occupied by their more ‘successful’ and ‘vigorous’ counterparts, the bacteria. Here we outline some of the evidence gathered by an increasingly large and productive
group of scientists that demonstrates not only that the Archaea contribute significantly to global nutrient cycling, but also that they compete successfully in ‘mainstream’ environments. Recent data suggest that the Archaea provide the major routes for ammonia oxidation in the environment.
Archaea also have huge economic potential that to date has only been fully realized in the production
of thermostable polymerases. Archaea have furnished us with key paradigms for understanding fundamentally conserved processes across all domains of life. In addition, they have provided numerous exemplars of novel biological mechanisms that provide us with a much broader view of the forms that life can take and the way in which micro-organisms can interact with other species.
That this information has been garnered in a relatively short period of time, and appears to represent only a small proportion of what the Archaea have to offer, should provide further incentives to microbiologists to investigate the underlying biology of this fascinating domain.
Que:Differe between facultative aerobics and anaerobics?
ReplyDeleteThe difference lies in their intermediate metabolism and the way they obtain the energy necessary for their growth and multiplication, the optional aerobic term establishes as the ideal growth condition the presence of oxygen, however at lower partial pressures of oxygen, these bacteria can follow growing. While the facultative anaerobic term establishes an ideal growth condition for the absence of oxygen, however, if the oxygen partial pressure rises in the medium, it is non-toxic to these microorganisms and can continue to grow.