Microorganisms are the oldest inhabitants of the planet earth. They have been here since approximately 3.6 billion years. Due to the relative ease of handling them in lab, they have been the model for understanding many fundamental cellular processes.
This paper will take the students into the exciting and amazing world of microbes. Salient features of bacteria, archeae, fungi, algae, viruses, and protozoa will be discussed, besides their application in food, pharmaceuticals, and bioremediation.
Happy to see the performance at least in my section of paper of GAM. :)
ReplyDeleteplease fill in more details
ReplyDeleteDr Winkle Weinberg, an infectious diseases expert, reckons that when we have a cold and cough the virus particles can travel at 320 kilometres an hour and up to 900 metres. That is faster than a passenger jet at takeoff!
ReplyDeleteIn some areas of the Indian ocean the sea surface lights up at night. It is so bright that one can read a newspaper. This light is caused by tiny sea algae, the Dino-flagellata. Sometimes the lightened surface has a diameter of more than 1.5 km. so they can be used further and should be having some wider applications too..
ReplyDeletebut there are some disadvantages....Dinoflagellates are perhaps best known as causers of harmful algal blooms. About 75-80% of toxic phytoplankton species are dinoflagellates , and they cause “red tides” that often kill fish and/or shellfish either directly, because of toxin production, or because of effects caused by large numbers of cells that clog animal gills, deplete oxygen, etc.
Dinoflagellate toxins are among the most potent biotoxins known. They often accumulate in shellfish or fish, and when these are eaten by humans they cause diseases like paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP) etc.
but also they are second diatoms as marine primary producers
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ReplyDeleteQ: how much number of e.coli will multiply in one week (at 20 mins per division). Compare its mass with the mass of earth
ReplyDeleteOr
Q: how bacterial natural division time is 20 min. Is a Misconception
Ans.. Single e.coli cell multiplies as 2^n
In a week =10080mins
i.e for 1 week the bacteria will divide =10080/20 =504 times
Hence the bacteria will divide 2^504 = 5.23742497e151
Hence 5.23742497e151 number of bacteria will be found
Comparing bacterial mass with earth's mass
Mass of earth is 5.972 × 10^24 kg
i.e 5.972e27g
Mass of single bacteria is 10^-12
While mass of total e.coli after one week will be
5.23742497e151 x 10^-12 = 5.237425e+139g
Which is way larger Than the mass of earth hence the life span of a bacteria can't be 20 mins
The conception of 20 mins generation time comes from laboratory where all the favourable conditions are provided to the bacteria without any competition.
This comment has been removed by the author.
ReplyDeleteE.coli can double in about 20 mins. So in 20 mins there will be 2 E.coli . In 40 mins , it will be 4 . In 24 hours it will be 4,722,366,869,645,213,696.
ReplyDelete1 hr- 60 mins -= 3 times = 8 cells
24hr-1440mins =72 times=2^72=4,722,366,482,869,645,213,696
7days-168hrs-10080mins=504times=2^504=52,374,249,726,338,269,920,211,035,149,241,586,435,466,272,736,689,036,631,732,661,889,538,140,742,474,792,878,132,321,477,214,466,514,414,186,946,040,961,136,147,476,104,734,166,288,853,256,441,430,016
Hence E.coli in a week will be 5.23742497263e151 ! a very huge number.
Mass of E.coli is 1 picogram (pico=10-12)
Mass of Earth is 5.9722×1024 kg
As the number of E. coli forming in a week is high so its mass will be high than Earth .
The conception of this huge number of E coli in week on Earth is failed due to unfavourable situations may kill E.coli and all nutrients necessary for its growth may not exist all everywhere. Thus this much E.coli is not found on earth in a week.
It takes about forty minutes to make one complete copy of the E. coli genome. Therefore, each generation of E. coli should last just under an hour. Instead, E. coli can divide (under ideal conditions) in as little as 20 minutes. How is this possible?
It turns out that E. coli can begin a new round of DNA replication before the previous round is complete. When the cell splits in two, each daughter cell receives a strand of DNA that is already in the process of being copied. That is, the daughter cell receives DNA that is halfway prepared for the eventual granddaughter cells.
The concept of E.coli dividing in 20 mins is satisfied in optimal lab conditions.
http://www.cellsalive.com/ecoli.htm
Spectrophotometer can't differentiate between live and dead cells but in the death phase of the growth curve the optical density decreases , why is that?
ReplyDeleteDuring the death phase the bacterial membrane is damaged and the cytoplasm leaks out , so the refractive index of the medium is reduced. Thus the scattering of light by the cells is decreased which ultimately decreases the optical density.
18MBT022
Q : why sometimes the lag phase in microbial growth is prolonged or why the cells don't enter the log phase?
ReplyDeleteA : it highly depends on the initial inoculum size used. Higher size is proportional to faster transition. This also suggests that nutrient utilisation
by the cells is increased as more amount of exoenzymes are secreted which helps better absorption ( shows leaky nature of membrane). Distribution of nutrient utilisation is more effective with cells inoculated with high amount than compared to smaller inoculum size.
Q : ocuurence of polio increased after using better sanitation , hygienic practices. Explain?
ReplyDeleteA : the argument can be explained using the hygiene hypothesis which states that lack of early childhood exposure to infectious agents, symbiotic microorganisms (such as the gut flora or probiotics), and parasites increases susceptibility to allergic diseases by suppressing the natural development of the immune system. In particular, the lack of exposure is thought to lead to defects in the establishment of immune tolerance. Polio being a enterovirus also is related. Another theory called the "old friends hypothesis" which some claim offers a more rational explanation for the link between microbial exposure and inflammatory disorders.[7] He argues that the vital microbial exposures are not colds, influenza, measles and other common childhood infections which have evolved relatively recently over the last 10,000 years, but rather the microbes already present during mammalian and human evolution, that could persist in small hunter gatherer groups as microbiota, tolerated latent infections or carrier states. He proposes that humans have become so dependent on these "old friends" that their immune systems neither develop properly nor function properly without them. Hence polio being exposed at adulthood tends to be more severe if not encountered first as no memory is generated.
Q ocuurence of polio increased after using better sanitation , hygienic practices. Explain?
ReplyDeletePolio virus spreads through infected faeces or sometimes through sneezing and coughing.
Earlier by the prolonged use of ash there would be mild form of virus present from childhood which generated memory response and made body resistant to it. But after the sudden use of hand wash all the virus was eliminated and a mild dose of virus could generate polio and paralysis.
18MBT015
Q- Why Oxygen is 21% only in atmosphere?
ReplyDeleteAns-Why is oxygen 21% in the atmosphere?
In atmosphere 21% is oxygen, 78% is nitrogen and 1% is other gases. This is due to reason that the oxygen is highly reactive whereas nitrogen is not react at atmosphere temperature with any one. If the % of gases are change vise versa for oxygen and nitrogen means if oxygen’s percentage is 78% and nitrogen’s percent is 21% there may be chance of fire on earth surface as oxygen is reactive at atmospheric condition and amount of it is very high.
Here 78% N2 works as an inert gas for atmospheric reaction and because of which reaction rate becomes slow down. Because of this reason the amount of oxygen is 21%.
Why don't the current oxygen level of earth's atmosphere exceed 21% ?
ReplyDeleteThe trees only provide us with about approximately 15% oxygen through photosynthesis but the oceans through the phytoplanktons (algal planktons) provide us 70-80% of oxygen as a by product of photosynthesis. Not only the phytoplanktons provide us with oxygen when they are alive but also posthumously (after the death of the originator). So we can say that this is because of the phytoplanktons that the oxygen level remains constant. But this level can be depleted if ocean is polluted and deforestation continues.
18MMB023
Why oxygen level of earth's atmosphere remains constant?
ReplyDeleteRather than plants, the marine plankton produces 70-85% of the atmospheric oxygen. By burning of fossil fuels the co2 level of earth is increasing day by day which lead to global warming. The growth of plankton is dependent on light level and nutrition level of the sea. Plankton live better in cold water than warm water. The increased level of carbon dioxide leads to global warming which effect on the temperature of ocean and the growth of planktons. Hence the atmospheric level of oxygen is not increasing.
18MMB005
Why don't the current oxygen of Earth's atmosphere exceed 21% ?
ReplyDeleteThe trees provide us with approximately 15% oxygen but the ocean through the phytoplanktons (algal planktons) provide us 70-80% of oxygen as a by product of photosynthesis. Not only they provide us with oxygen when they are alive but also posthumously (after the death of the originator). So we can say that this is because of the phytoplanktons that the oxygen level remains constant. But this level can be depleted if oceans are polluted and deforestation continues.
18MMB023
Fungal garden of insects is actually quite interesting way of interaction seen in nature between the insects and fungi.
ReplyDeleteInsects like Ants of genera "Cy phomyrmex" , Termites like "Odontotermes gurda" actively cultivate the fungal growth in exponential amount, by cultivating the spores of fungi sfungi such as "Leucoagaricus" .
After certain amount of time and sufficient growth of Fungi is done, the insects start consuming them as the The source of nutrition .
We can compare this peculiar activity and interaction with humans growing their own crops and then eating it themselves !
QUES: FUNGAL GARDEN OF INSECTS
ReplyDeleteANS: The Fungal garden of insects is an example of mutualism as the insect and fungus are involved in this interaction completely depend on each other.
Species involved are
Fungi- Lepiotaceae
Insect(ant)- Atta colombica
The interaction begins when the foraging ants from the "attine tribe" leaves the nest and brings the leaves to the nest without ingesting any of its chemical components. Now the worker ants from the same tribe cuts them, chew them and makes the pulp which will be used as the substrate.The queen ant "Atta colombica" leaves the nest and brings the piece of fungi "Lepiotaceae" in her mouth and inoculates the prepared substrate with the fungi, within few days fungi cultivates on the substrate, after that all the ants feed on this fungi and therefore both the species are benefited and thus fungus cannot live without ants and ants cannot survive without fungus.This is how they show mutualistic interaction.
Roll no. 18MMB029
QUES:Fungal garden of insects
ReplyDeleteANS: Insects:Atta cephalotes and Acromyrmex echinatior(ants)
Fungus:Leucoagaricus gongylophorus, a Basidiomycetes fungus
"Atta cephalotes" and "Acromyrmex echinatior" carry freshly cut leaves to the nest where they process this material into substrate for their symbiont"leucoagricus gonylophorous"by chewing it into minute pieces that are mixed with saliva.These leaf pieces are deposited on the edges of the garden,after which the fungi are added to the substrate which will grow within few days, as fungi are main source of food for ants therefore, the ants will feed upon them,thereby showing mutualistic relationship as fungi dependent on the ants for the substrate whereas the ants are dependent on fungi as their main food component.
QUES:Fungal garden of insects
ReplyDeleteANS: Insects:Atta cephalotes and Acromyrmex echinatior(ants)
Fungus:Leucoagaricus gongylophorus, a Basidiomycetes fungus
"Atta cephalotes" and "Acromyrmex echinatior" carry freshly cut leaves to the nest where they process this material into substrate for their symbiont"leucoagricus gonylophorous"by chewing it into minute pieces that are mixed with saliva.These leaf pieces are deposited on the edges of the garden,after which the fungi are added to the substrate which will grow within few days, as fungi are main source of food for ants therefore, the ants will feed upon them,thereby showing mutualistic relationship as fungi dependent on the ants for the substrate whereas the ants are dependent on fungi as their main food component.
ROLL NO: 18MMB026
Q) Why is the lid bigger than the base in petriplate?
ReplyDeleteANS:The lid is bigger because if it touches the bench the lid gets contaminated and not the culture. Also, if the plate is kept upside down the bacteria contaminates the culture.
Q) Why the petriplate is 90mm in diameter?what is the height of petriplate?
ANS: The microorganisms require a larger surface area for growth thus, pertiplate has this diameter. The height of pertiplate is 15mm.
Q) What are fungal garden of insects?
ANS: Some insect species such as ants species "Trachymyrmex septentrionalis" are always found in association with a certain fungus, and some fungi only with a certain insect.In some cases the insect feeds on its partner or on the partner's own partly digested food.In others the partner lives in the alimentary tract and digests food the insect cannot digest for itself.Later the insects lead upto actively cultivating fungus. This serves as the food product for the insect which it feeds on later.
Q) Why white labcoats for science students and blue labcoats for engineering ?
ANS: In case of science students:lab coats protect against accidental spills, e.g., acids. In this case they usually have long sleeves and are made of an absorbent material, such as cotton, so that the user can be protected from the chemical.
In case of engineering students: The colour is blue because they are made of Flame Resistant material.
18MBT001
Que. Which bacteria has higest speed?
ReplyDeleteAns:- "It has been reported that the flagella of Spirillum serpens rotate at a rate of 2,400 r/min, while the body rotates at 800 r/min and the estimated forward speed of the cell is 50 µm/s. Vibrio comma, a polar flagellate, has been reported to move at a rate of 200 µm/s."
Source:- Pleczar & Chan. Microbiology. 4th edition. New York: McGraw Hill, 1977: 86.
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ques: the maximum recorded speed of the bacteria?
ReplyDeleteans: vibrio , a polar flagellate ,has been reported to move at highest speed of 200µm/s."
ques: the maximum recorded speed of the bacteria?
ReplyDeleteans: vibrio, a polar flagellate, has been reported to move at highest speed of 200µm/s.
ROLL NO: 18MMB026
Ques: What is the maximum recorded speed for bacteria ?
ReplyDeleteAns: A) The maximum speed - 200µm/s
bacteria is Vibrio comma
B) The second maximum speed is seen in Bellovibrio
bacteriovorous that is reported to be 100 µm/s
ROLL NO. 18MMB029
Question :- What is the maximum recorded speed for bacteria ?
ReplyDeleteAns:-Bacteria can reach speeds from 2 microns per second (Beggiatoa, a gliding bacteria) to 200 microns per second (Vibrio comma, polar bacteria). Speed varies with type of bacteria, but flagellates are undoubtedly faster than gliders.
Roll No.:- 18MMB010
Question: Kuru Disease..
ReplyDeleteAns:-Shirley Lindenbaum is notable for her medical anthropological work on kuru. and a Daniel Carleton Gajdusek , a virologist and Vincent Zigas , a medical doctor, first started doing research on the disease in 1957.
Roll No. 18MMB015
Why don't the current oxygen level of earth's atmosphere exceed 21% ?
ReplyDeleteANS:-Oxygen is a highly reactive gas which readily forms oxides. It is primarily present in it's diatomic form while in the atmosphere
Oxygen is being renewed constantly by the process of photosynthesis done by plants in which they use CO2 & releasing out O2 which provides 15% of total oygen and planktons provides almost 80% of oxygen.
Animals and humans in turn uses O2 and releases out CO2 through respiration.
The amounts of oxygen released and consumed are nearly same, which maintains an equilibrium in atmosphere.
If the amount of oxygen was any greater, all life would be at risk.
The probability of forest fire increases by 70 percent for each 1 percent rise in oxygen concentration above the present level.
But if there is too little in the air humans and animals die which allow less air consumption and more oxygen.
The oxygen molecules just get transferred to a different substance. The molecules are all still there, just in a different form. Its called the The Law on the Conservation of Matter -- matter cannot be either created or destroyed.
Conclusion: Nature always balances. Its a natural equilibrium.
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E.coli can double in about 20 mins. So in 20 mins there will be 2 E.coli . In 40 mins , it will be 4 . In 24 hours it will be 4,722,366,869,645,213,696.
ReplyDelete1 hr- 60 mins -= 3 times = 8 cells
24hr-1440mins =72 times=2^72=4,722,366,482,869,645,213,696
7days-168hrs-10080mins=504times=2^504=52,374,249,726,338,269,920,211,035,149,241,586,435,466,272,736,689,036,631,732,661,889,538,140,742,474,792,878,132,321,477,214,466,514,414,186,946,040,961,136,147,476,104,734,166,288,853,256,441,430,016
Hence E.coli in a week will be 5.23742497263e151 ! a very huge number.
Mass of E.coli is 1 picogram (pico=10-12)
Mass of Earth is 5.9722×1024 kg
As the number of E. coli forming in a week is high so its mass will be high than Earth .
The conception of this huge number of E coli in week on Earth is failed due to unfavourable situations may kill E.coli and all nutrients necessary for its growth may not exist all everywhere. Thus this much E.coli is not found on earth in a week.
It takes about forty minutes to make one complete copy of the E. coli genome. Therefore, each generation of E. coli should last just under an hour. Instead, E. coli can divide (under ideal conditions) in as little as 20 minutes. How is this possible?
It turns out that E. coli can begin a new round of DNA replication before the previous round is complete. When the cell splits in two, each daughter cell receives a strand of DNA that is already in the process of being copied. That is, the daughter cell receives DNA that is halfway prepared for the eventual granddaughter cells.
The concept of E.coli dividing in 20 mins is satisfied in optimal lab conditions.
http://www.cellsalive.com/ecoli.htm
18MMB013
Question:-What is the kuru disease? How to infect human ? Who was first time work on it.?
ReplyDeleteAns:-Kuru is a very rare disease, incurable neurodegenerative disorder.It is caused by an infectious protein (prion) found in contaminated human brain tissue.
People can contract the disease by eating an infected brain or coming into contact with open wounds or sores of someone infected with it. Kuru developed primarily in the Fore people of New Guinea when they ate the brains of dead relatives during funeral rites.
Daniel Carleton Gajdusek was an American physician and medical researcher who was the co-recipient (with Baruch S. Blumberg) of the Nobel Prize in Physiology or Medicine in 1976 for work on kuru, the second human prion disease demonstrated to be infectious.
Roll No.:-18MMB010
Kuru disease
ReplyDeleteIn 1982 , American neurobiologist Stanely Prusiner coined the name prions for proteinaceous infectious particle.
some of tribes in New Guinea have suffered from disease called Kuru . Transmission of kuru is apparently related to the practice of cannibalistic rituals . Carleton Gajdusek received the Nobel prize for Physiology and medicine in 1976 for investigations of Kuru . In this disease symptoms include such as tremors , loss of coordination and neurodegeneration .
What would happen if all the microorganisms in the world disappeared ?
ReplyDelete-All microbial diseases would vanish.
-Most nutrients would stop being made or cycled.Rapid exhaustion of available macronutrients and micronutrients.
-Waste would accumulate indefinitely.
-All ruminant animals — like cows,sheep, and goats — would starve.
Humans and other life would survive in the short term, but eventually would die.
-Microbes fix the majority of nitrogen in the atmosphere to forms that are usable by other organisms. Microbes cycle carbon and oxygen in organic matter.
-Microbes allow us to digest more of the nutrients in our foods and protect us from infections.
-If microbe also refers to protists then the vast majority of all ocean life will be gone, phytoplankton and zooplankton are predominantly diatoms and bacteria.
-The biomass of ocean systems is an inverted pyramid and if the large organisms get nothing to eat then they will very quickly die off and this would create an imbalance in the ecosystem.
-Quality of life would quickly diminish.
-Gradually as the nitrogen cycle halts plants will develop yellow streaks and die, animals will struggle to feed themselves, and the flow of energy from the sun to life will cease and basically everything will die, eventually.
Thus something terrible would happen if all microbes instantly disappeared.
18mmb023
Which is better aerobic respiration or anaerobic respiration ?
ReplyDeleteAerobic respiration is much more efficient at making ATP than anaerobic processes like fermentation. Without oxygen, the Krebs Cycle and the Electron Transport Chain in cellular respiration will not work any longer. This forces the cell to undergo the much less efficient fermentation. While aerobic respiration can produce up to 38 ATP, the different types of fermentation can only have a net gain of 2 ATP.
18mmb023
Why don't the evolution select aerobic respiring organisms ?
ReplyDeleteThe most ancient type of respiration is anaerobic. Since there was little to no oxygen present when the first eukaryotic cells evolved through endosymbiosis, they could only undergo anaerobic respiration. This was not a problem,since those first cells were unicellular. Producing only 2 ATP at a time was enough to keep the single cell running.
As multicellular eukaryotic organisms began to appear on Earth, the larger and more complex organisms needed to produce more energy. Through natural selection, organisms with more mitochondria that could undergo aerobic respiration survived and reproduced, passing on these favorable adaptations to their offspring.
18mmb023
Q What is nitrogen fixation?
ReplyDeleteNitrogen fixation is a process that causes the strong two atom of nitrogen molecule found in atmosphere to break apart and combine with other atoms. Nitrogen is fixed when combined with oxygen or hydrogen.
1 Atmospheric nitrogen fixation where enormous energy of lightning break nitrogen molecules apart and nitrogen atoms are combined with oxygen forming nitrogen oxides which dissolve in rain forming nitrates.
2 Industrial nitrogen fixation where at higher temperature and use of catalyst atmospheric nitrogen and hydrogen are combined to form ammonia.
3 Biological nitrogen fixation where specialise bacteria on soil have capability to combine atmospheric nitrogen with hydrogen to form ammonia.
18MBT027
Question: What is the meaning of Fixed nitrogen?
ReplyDelete- Living organisms need nitrogen to form nucleic acids, proteins, and other molecules.Fixed nitrogen is nitrogen gas, N2, that has been converted to ammonia (NH3), an ammonium ion (NH4), nitrate (NO3), or another nitrogen oxide so that it can be used as a nutrient by living organisms.
Some nitrogen-fixing bacteria have symbiotic relationships with some plant groups, especially legumes.Bacteria that change nitrogen gas from the atmosphere into solid nitrogen usable by plants are called nitrogen-fixing bacteria. These bacteria are found both in the soil and in symbiotic relationships with plants.
18mmb015
Que: what is fixed nitrogen?
ReplyDeleteThe atmospheric nitrogen converted into inorganic compound which can be used by plants is known as fixed nitrogen. The process of converting atmospheric nitrogen into fixed nitrogen is known as nitrogen fixation.
Only prokaryotic organisms are able to do nitrogen fixation.
18MMB005
Dots programme against tuberculosis?
ReplyDeleteDots(Directly observed treatment short course) for TB. It is internationally recognized because of cost-effective benefits.
Dots programme against tuberculosis?
ReplyDeleteDots(Directly observed treatment short course) for TB. It is internationally recognized because of cost-effective benefits.
18mbt015
Ques:What will happen if there were no microbes inside or outside the body?
ReplyDeleteAns: Most species on Earth would become extinct as:
1. All plants would die.
plants are reliant upon bacteria to survive. If they don't have microbes to take in and convert chemical compounds into usable parts, they'll rapidly lose to ability to produce fuel via photosynthesis and will quickly die.
2.All ruminant animals would starve
They can not digest cellulose so they relay on gut microbes that can breakdown cellulose,allowing them to digest and absorb the nutrient from the plant.
3.Biomass would likely begin to accumulate,particularly at molecular level creating reservoirs of biogeochemical waste that no biological entity could transform, it would lead to disruption of biogeochemical recycling upon which all life ultimately depends.
Roll no.: 18MBT034
Q. how does viruses are named??
ReplyDeleteANS: For the first 60 years of virus discovery, there was no system for classifying viruses. Consequently viruses were named haphazardly, a practice that continues today.
Lwoff, Horne, and Tournier suggested a comprehensive scheme for classifying all viruses in 1962. Their proposal used the classical Linnaean hierarchical system of phylum, class, order, family, genus and species. The complete scheme was not adopted, but animal viruses were soon classified by family, genus, and species.
An important part of the scheme proposed by Lwoff and colleagues is that viruses are grouped according to their properties, not the cells they infect. The nucleic acid genome was also recognized as a primary criterion for classification. Four characteristics were to be used for the classification of all viruses:
1.Nature of the nucleic acid in the virion
2.Symmetry of the protein shell
3.Presence or absence of a lipid membrane
4.Dimensions of the virion and capsid
Other characteristics which were subsequently added include the type of disease caused, and which animals and tissues are infected. With the development of nucleic acid sequencing technologies in the 1970s, genomics has played an increasingly important role in taxonomy. Today new viruses are assigned to families based on the nucleic acid sequence of their genome.
The International Committee on the Taxonomy of Viruses (ICTV) is charged with the task of developing, refining, and maintaining a universal virus taxonomy. A complete catalog of known viruses is maintained by the ICTV at ICTVdb. Although the ICTV nomenclature is used to classify animals viruses, plant virologists do not place their viruses into families and genera, but use group names derived from the prototype virus.
Because the viral genome carries the blueprint for producing new viruses, virologists consider it the most important characteristic for classification.
roll no. 18mbt012
For the first 60 years of virus discovery, there was no system for classifying viruses. Consequently viruses were named haphazardly, a practice that continues today.
ReplyDeleteVertebrate viruses may be named according to the associated diseases (poliovirus, rabies), the type of disease caused (murine leukemia virus).
Some viruses are named for where they were first isolated (Sendai virus, Coxsackievirus), for the scientists who discovered them (Epstein-Barr virus), or for the way people imagined they were contracted (dengue = ‘evil spirit’; influenza = ‘influence’ of bad air).
By the early 1960s, new viruses were being discovered and studied by electron microscopy. As particles of different sizes, shapes, and composition were identified, it became clear that a systematic nomenclature was needed.
In 1962 Lwoff, Horne, and Tournier suggested a comprehensive scheme for classifying all viruses. Their proposal used the classical Linnaean hierarchical system of phylum, class, order, family, genus and species. The complete scheme was not adopted, but animal viruses were soon classified by family, genus, and species.
An important part of the scheme proposed by Lwoff and colleagues is that viruses are grouped according to their properties, not the cells they infect. The nucleic acid genome was also recognized as a primary criterion for classification. Four characteristics were to be used for the classification of all viruses:
1).Nature of the nucleic acid in the virion
2).Symmetry of the protein shell
3).Presence or absence of a lipid membrane
4).Dimensions of the Virion and Capsid
The International Committee on the Taxonomy of Viruses (ICTV) is charged with the task of developing, refining, and maintaining a universal virus taxonomy. A complete catalog of known viruses is maintained by the ICTV at ICTVdb.
18MMB015
18mbt025
ReplyDeleteNidhi Patel
Role of Accessory pigments in Photosynthesis
Accessory pigments are light-absorbing compounds, found in photosynthetic organisms, that work in conjunction with chlorophyll a. They include other forms of this pigment, such as chlorophyll b in green algaland higher plant antennae, while other algae may contain chlorophyll c or d.
• In addition, there are many non-chlorophyll accessory pigments, such as carotenoids or phycobiliproteins, which capture a wide spectrum of wavelength of light and transfer that light energy to photosystemchlorophyl
• carotenoids, also serve to absorb and dissipate excess light energy, or work as antioxidants.
• Accessory pigments are responsible for donating electron to the reaction center.
• They conduct the carbon dioxide reaction of photosynthesis and lastly splits water molecule into hydrogen ion and oxygen.
ReplyDelete18mbt025
Nidhi Patel
Q. Define DOTS
DOTS was the Directly Observed Treatment Short course strategy announced by the World Health Organisation (WHO)for the worldwide control of TB. All countries with a TB problem were to provide standardized short course drug treatment to, at least, all sputum smear positive TB patients.
DOTS had five components which were initially as follows.
• Sustained financial and political commitment .
• Diagnosis of TB by quality ensured sputum smear microscopy.
• Standardized short course anti TB treatment (SCC) given under direct and supportive observation (DOTS).
• A regular uninterrupted supply of high quality anti TB drugs.
• Standardized recording and reporting.
DOTS involved treatment with a four drug regimen. These were isoniazid (INH), Rifampicin (Rif), Prazinamide (PZA) and Ethambutol (EMB) for 6-9 months.
The technical strategy for DOTS was developed by Karel Styblo of the International Union Against TB & Lung Disease in the 1970s and 80s, primarily in Tanzania.
In 1990 approximately 60% have been benefitted from this care where less than 2% of infectious TB patients were being detected and cured, with DOTS treatment services . Since 1995, 41 million people have been successfully treated and up to 6 million lives saved through DOTS and the Stop TB Strategy.
Now a days DOTS-Plus is used for multi-drug-resistant tuberculosis (MDR-TB).
Q) What is single cell protein?
ReplyDelete•Single-cell protein (SCP) refers to protein derived from cells of microorganisms such as yeast, fungi, algae, and bacteria, which are grown on various carbon sources for synthesis.
•The term single cell protein was introduced in the 1960s to describe protein-rich foods manufactured from yeasts that served as dietary supplements for livestock and humans.
•It is of great nutritional value because it contains a high protein, lipid, and vitamins etc which provide great health benefits to the people.
•The dried cells of microorganisms or the whole organism is harvested and consumed.
•SCP is a protein source for human food supplements and animal feeds.
•SCP production may have potential for feeding the ever-increasing world population. Massive quantities of SCP can be produced in a single day.
•As a source of protein it is very promising with potential to satisfy the world shortage of food while population increases. There are several carbon sources that are used as energy sources for microorganisms for growing and producing SCP.
•Example: Spirulina is a single cell protein, which is given to people to enrich them with the vitamin. It prevents the accumulation of cholesterol in the human body and lowers the blood sugar level.
Advantage of SCP:
1. The SCP is rich in high quality protein.
2. They can be produced all the year round and are not dependent of the climate (except the algal processes).
3. The microbes are very fast growing and produce large quantities of SCP from relatively very small area of land.
4. They use low cost substrates and, in some cases, such substrates which are being wasted and causing pollution to the environment.
5. When the substrate used for SCP process is a source of pollution, SCP production helps reduce pollution.
6. Strains having high biomass yields and a desirable amino acid composition can be easily selected or produced by genetic engineering.
7. Some SCPs are good sources of vitamins, particularly B-group of vitamins, as well, e.g.. yeasts and mushrooms.
8. Mushrooms are considered as delicacy in the human diet.
9. At present, SCP appears to be the only feasible approach to bridge the gap between requirement and supply of proteins.
What will happen if there were no Microbes...
ReplyDelete“Life would not long remain possible in the absence of microbes.”—Louis Pasteur
Microbes fix the majority of nitrogen in the atmosphere to forms that are usable by other organisms. Microbes cycle carbon and oxygen in organic matter. Microbes allow us to digest more of the nutrients in our foods and protect us from infections. If microbe also refers to protists then the vast majority of all ocean life will be gone, phytoplankton and zooplankton are predominantly diatoms and bacteria.
Without all of this, all life on earth would eventually collapse. Ocean life would probably die first, almost all of the energy cycling in the oceans comes from photosynthetic phytoplankton and without that everything else would quickly starve. The biomass of ocean systems is an inverted pyramid and if the large organisms get nothing to eat then they will very quickly die off.
Animals will have less effective digestion and certain species will completely starve. Most grass eaters rely on microbes in their guts to actually digest any of the matter that they consume. But gradually as the nitrogen cycle grinds to a halt plants will develop yellow streaks and die, animals will struggle to feed themselves, and the flow of energy from the sun to life will cease and basically everything will die, eventually.
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Application of Microorganisms...
ReplyDeleteFrom Plant Disease to shampoo and salad Dressing:
Xanthomonas campestris is an aerobic, Gram-negative rod known to cause the black rot in plants. Host associated, over 20 different pathovars of X. campestris have been identified by their distinctive pathogenicity on a wide range of plants including crops and wild plants.
In contrast to its effects in plants, xanthaan has no adverse effects when ingested by humans. Consequently, xanthan can be used as a thickener in foods, such as dairy products and salad dressing, and in cosmetics such as cold creams and shampoos.
By pure culture fermentation, X. campestris can produce an extracellular polysaccharide known as xanthan gum that is commercially manufactured as a stabilizing agent used in many everyday products including salad dressing or toothpaste. X. campestris is a model organism for studying interactions between plant and bacteria. Due to the deficit in crops, further research of this bacteria is in progress in hopes of learning how to make plants resistant to this pathogen.
X. campestris ferments a stabilizing agent called xanthan gum that is used in many everyday products. It was first commercially produced at Kelco Company, a major pharmaceutical company. This polysaccharide is an ingredient in products like Kraft French dressing, Weight Watchers food, Wonder Bread products, and more. From carbohydrate fermentation by X. campestris, xanthan gum’s pseudoplastic, easily blended characteristic allows it to be used as a thickener by increasing viscosity of a liquid. In addition, xanthan gum also prolongs oil and gas wells even after production. Either pumped into the ground or using high pressure sandblasting, mixing water and xanthan gum into the wells will help thicken the liquid to release crude products of oil and cut through rocks in gas and oil wells. Xanthan gum costs $7 per pound compared to cornstarch for 89 cents per pound.
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application of microbes in bioremediation and few of the more common microbial products that are integral part of modern life:
ReplyDeletebioremediation: using Microbes to Clean up Pollutants In 1988, scientists began using microbes to clean up pollutants and toxic wastes produced by various industrial processes. For example, some bacteria can actually use pollutants as energy sources; others produce enzymes that break down toxins into less harmful substances. By using bacteria in these ways—a process known as bioremediation—toxins can be removed from underground wells, chemical spills, toxic waste sites, and oil spills, such as the massive oil spill from a British Petroleum offshore drilling rig in the Gulf of Mexico in 2010 . In addition, bacterial enzymes are used in drain cleaners to remove clogs without adding harmful chemicals to the environment. In some cases, microorganisms indigenous to the environment are used; in others, genetically modified microbes are used. Among the most commonly used microbes are certain species of bacteria of the genera Pseudomonas and Bacillus. Bacillus enzymes are also used in household detergents to remove spots from clothing.
Biopolymers Biopolymers are microbially produced polymers, primarily polysaccharides, used to modify the flow characteristics of liquids and to serve as gelling agents. These are employed in many areas of the pharmaceutical and food industries. Biopolymers include (1) dextrans, which are used as blood expanders and absorbents; (2) Erwinia polysaccharides used in paints; (3) polyesters, derived from Pseudomonas oleovorans, which are used for specialty plastics; (4) cellulose microfibrils, produced by an Acetobacter strain, that serve as a food thickener; (5) polysaccharides such as scleroglucan used by the oil industry as drilling mud additives; and (6) xanthan polymers, which have a variety of applications as food additives as well to enhance oil by thickening drilling mud. This use of xanthan gum, produced by Xanthomonas campestris, represents a large market for this microbial product.
Biosurfactants: Biosurfactants are amphiphilic molecules; that is, they possess both hydrophobic and hydrophilic regions. Thus they partition at the interface between fluids that differ in polarity, such as oil and water. For this reason, they are used for emulsification, increasing detergency, wetting, and phase dispersion, as well as solubilization. These properties are especially important in bioremediation, oil spill dispersion, and enhanced oil recovery. The most widely used microbially produced biosurfactants are glycolipids. These are carbohydrates that bear long-chain aliphatic acids or hydroxy aliphatic acids. They can be isolated as extracellular products from a variety of microorganisms, including pseudomonads and yeasts.
Organic Acids Simply reading the ingredient list on most processed foods will illustrate the widespread use of the organic acids such as citric, acetic, and lactic acids. These acids are principally used as preservatives. Organic acid production illustrates how the concentration of trace elements can influence product yield Citric acid fermentation involves limiting the amounts of trace metals such as manganese and iron to stop Aspergillus niger growth at a specific point. The medium often is treated with ion exchange resins to ensure low and controlled concentrations of available metals. Generally, high sugar concentrations (15 to 18%) are used, and copper has been found to counteract the inhibition of citric acid production by iron. This reflects the regulation of glycolysis and the tricarboxylic acid cycle (recall that citric acid is a constituent of the TCA cycle). After the active growth phase, when the substrate level is high, citrate synthase activity increases and the activities of aconitase and isocitrate dehydrogenase decrease. This results in citric acid accumulation and excretion by the stressed microorganism.
q. application of microorganisms
ReplyDelete= Agricultural improvers:
-nematodes
Tiny worms that are invisible to the naked eye and natural enemies of pest insects. They are used as plant protection
product.
Agriculture and microorganisms have a natural bond. The fertilization of the land, the production of fodder for cattle, compost heaps. These are all traditional applications of microbes on the farm. Without microbes, plants grow badly or not at all, and agriculture would be impossible. We use microbes more and more frequently to increase crop yields. Thanks to microorganisms, we can strongly reduce the number of chemical pesticides and herbicides in agriculture.
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Single-cell proteins are the dried cells of microorganism, which are used as protein supplement in human foods or animal feeds. Microorganisms like algae, fungi, yeast and bacteria, utilize inexpensive feedstock and wastes as sources of carbon and energy for growth to produce biomass, protein concentrate or amino acids. Since protein accounts for the quantitatively important part of the microbial cells, these microorganisms, also called single cell protein as natural protein concentrate. With increase in population and worldwide protein shortage the use of microbial biomass as food and feed is more highlighted. Although single cell protein has high nutritive value due to higher protein, vitamin, essential amino acids and lipid content, there is a doubt to be replaced to the conventional protein sources due to their high nucleic acid content and slower in digestibility. They also may be considered as foreign material by body, which may subsequently results in allergic reactions.
ReplyDeleteYeast was the first microorganism whose importance as animal feed supplement was recognized almost a century ago. During World War I, Germany replaced half of imported protein sources by yeast. Pruteen was the first commercial single cell protein used as animal feed additive. From a nutritional viewpoint, Nucleic Acids (NA) content in SCP is one of the main factors hindering its utilization as food. Excessive intakes of NA lead to uric acid precipitation, causing health disorders, such as gout or kidney stone formation.
So, in human their NA contents must be reduced below 2%. Several technologies have been reported to reduce the NA content of microbial cells, including both chemical and enzymatic procedures. Chemical and enzymatic methods have disadvantages . Various microorganisms used for the production of SCP are bacteria (Cellulomonas, Alcaligenes, etc.), algae (Spirulina, Chlorella, etc.), molds (Trichoderma, Fusarium, Rhizopus, etc.) and yeast (Candida, Saccharomyces, etc.). Microorganisms can utilize a variety of substrate like agricultural wastes and effluents, industrial wastes, natural gas like methane, etc. that also help in decomposing pollutan
A variety of microorganisms and substrate are used to produce single cell proteins. Yeast is suitable for single cell protein production because of its superior nutritional quality . The supplementation cereals with single cell proteins, especially yeast, make them as good as animal proteins. The necessary factor considered for use of SCP is the demonstration of the absence of toxic and carcinogenic compounds originated from the substrates, biosynthesized by the microorganisms or formed during processing. High nucleic acid content and low cell wall digestibility are two of the most important factors limiting nutritional and toxicological value of yeast for animal or human consumption . As constituents of nucleic acid, purine compounds in human diet mostly metabolized to yield uric acid whose high concentration may lead to gout or renal stones. However, nucleic acid is not a toxic component and it causes only physiological effects at higher levels like any other essential dietary ingredients taken in larger amounts. It has been calculated that 100 lbs of yeast will produce 250 tons of proteins in 24 h. Algae grown in ponds can produce 20 tons (dry weight) of protein, per acre, per year.
Rapid automated testing of probiotic organism:
ReplyDeleteDefinition and Health benefits of Probiotics: The World Health Organization’s 2001 definition of probiotics is “live micro-organisms which, when administered in adequate amounts, confer health benefits on the host”.[1] This definition, although widely adopted, is not acceptable to the European Food Safety Authority because it embeds a health claim which is not measurable.[2] Etymologically, the term appears to be a composite of the Latin preposition pro (“for”) and the Greek βιωτικος(biotic), the latter deriving from the noun βιος (bios, “life”) [3]
Health benefits: Some digestive disease specialists are recommending the use of probiotic organisms to help in the treatment of disorders that frustrate conventional medicine, such as irritable bowel syndrome. Since the mid-1990s, clinical studies have established that probiotic therapy can help in the treatment of several gastrointestinal ills, may delay the development of allergies in children
Examples of Probiotic Organisms: There are hundreds of strains of probiotic bacteria. The most commonly used organisms include Lactobacillus sp. (such as L. acidophilus, L. casei, L. fermentum , L. rhamnosus) Bifidobacterium sp, (such as B. Bifidum, B. lactis and B. longum), Streptococcus thermophilus, Bacillus coagulans,and Enterococcus faecium.
Potency Testing: Probiotics offer a broad range of health benefits. As with any supplement, the efficacy of a probiotic depends on dosage. Essentially the titer of live organisms is the critical part in determining potency. Recommending an adequate dose for an individual patient requires clear knowledge of the potency of a product. Probiotic potency is specified as the numbers of viable cells of the beneficiary organism. Confidence in the accuracy of this number is essential for successful and consistent clinical results.
BioLumix Methodology for Potency Testing:
A calibration curve is generated to easily relate the number of colony forming units determined using the plate count method to the detection times (DT) in the BioLumix instrument. These calibration curves are embedded into the instrument software and are used to access the number of probiotic organisms present in the product sample for individual organisms. An example is shown in the Graph for the Lactobacillus acidophilus. Currently, individual calibration curves are available for the following organisms: L. casei, L. acidophilus, L. rhamnosus, L. bulgarus, B. coagulans, B. longum, B. bifidum, E. feacalis, and S. thermophilus. The procedure used to test sample cultures involves a single 1:10,000 dilution of the sample followed by the addition of 0.1 ml to the appropriate test vial. Organism growth may occur rapidly, often in less than 24 hr, and the BioLumix instrument generates an estimate of the cfu per gram of sample. This is a much more rapid method than the traditional plate methods that often takes 3-7 days for Lactobacillus species. Using the BioLumix rapid method can be much less expensive than traditional plate methods for Lactobacillus species as these organisms often require specialty media under conditions of low oxygen (candle jars).
Microbial contamination: Good manufacturing Practices must be applied in the manufacture of probiotic containing products. Contamination of probiotic products with undesirable microorganisms is possible in uncontrolled fermentation and during handling. Therefore, most probiotic batches need to be tested for indicator organisms such as coliforms and to also show the absence of potentially harmful organisms such as E. coli, Staphylococcus and Salmonella.
BioLumix Methodology for Microbial Contamination: The BioLumix simplified automated system can detect indicator organisms and objectionable organisms, if present, in a fraction of the time of traditional methods, with significantly less hands-on time. The system offers a wide variety of rapid assays for samples, including assays to detect yeast & molds, coliforms, E. coli, Staphylococcus, Pseudomonas and Salmonella
Microbially Induced Calcite Precipitation (MICP) is a viable technique which can be applied to various applications.
ReplyDeleteThis technique uses urease producing bacteria to facilitate calcite precipitation to bind soil particles and improve its strength.
Sporosarcina pasteurii has been proven to have high urease productivity and it has been used extensively. This technique is feasible for sustainable construction materials such as pavers, namely bio-pavers.
The same principle of MICP is used in Biogrouting –As hydraulic erosion is one of the main causes of failure within earth dams and embankments so one of the method to reduce or remove this erosion is through biogrouting where bacteria injected into the soil produce urease enzyme, which converts urea to ammonium and carbonate, causing calcite precipitation that binds soil grains together.
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Que : Application of microorganisms
ReplyDeleteBiological treatment of waste
Membrane bioreactors (MBR) have been used for decades as a good secondary treatment option in small municipalities for wastewater treatment. The use of aerobic or anaerobic microbial populations that feed on nutrients allows the treatment of suspended solids through membrane filtration. Membrane bioreactors have been added to increase the water treatment capacity of the Olympic village for the 2008 Beijing Olympics and to recycle 50% of the wastewater. The use of MBR treatment and other technologies has more than doubled the water treatment capacity of the Beixiaohe wastewater treatment plant by using a biological energy source.
Microbial populations can also be used to treat solids. Composting of organic matter, is one of the best ways to reduce solid waste volumes. Large composting facilities can make an odorless product from organic waste. Treatment under high temperatures has the ability to kill parasites and weeds that could be found in the initial waste. The method of industrial composting is an efficient method used by cities like Edmonton or Toronto in order to reduce the waste mass that needs to be transported to landfills.
Dr. Dominic Frigon works on the application of mathematical models to microbial populations for waste treatment systems and plans to work on the development of hydrogen and microbial fuel cells.
Bioproduction of hydrogen
Hydrogen can be produced by either photosynthetic or fermentative microbial populations.
Researchers discovered that under sulfur deprivation, cells from microalgae Chlamydomonas reinhardtii could produce molecular dihydrogen by a transfer of protons and electrons during a biophotolysis process, a chemical reaction in which the compounds break down under the action of photons. In a sulfur-lacking environment, Chlamydomonas reinhardtii accumulate starch and have an increased consumption of oxygen which leads to the degradation of water molecules to consume the oxygen atom and the release of dihydrogen. Sustained dihydrogen production can be attained in the absence of acetone and is dependant on the lighting at certain stages (there is an aerobic phase followed by an anaerobic phase in the absence of ambien oxygen), pH, the possible addition of sulfur as well as the use of mutant microalgae.
Indirect biophotolysis refers to a fermentation process under which purple, non-sulfur photosynthetic bacteria use sugars as a feedstock to produce dihydrogen and carbon dioxide in a nitrogen-deficient environment. Like direct biophotolysis, this process requires an energy input provided by photons.
Dark fermentation, on the other hand, uses organic matter as the primary feedstock. Under anaerobic conditions, the digestion of the substrate will yield dihydrogen gas, but also different acids and alcohols, such as ethanol or methanol. The yields in biohydrogen depend on the microbial populations, oxidation state, the primary feedstock, and the environmental conditions. Dark fermentation yields a lot of by-products, but does not require any light and can work with a wide array of feedstocks.
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Q Application of microorganisms
ReplyDeleteA
BIOSURFACTANT: Biosurfactants are amphiphilic compounds produced in living spaces or excreted extracellular hydrophobic and hydrophilic moieties that confer on the organism the ability to accumulate between fluid phases thus reducing surface and interfacial tension. Biosurfactants are produced by several microorganisms which include Acinetobacter sp., Bacillus sp, Candida antartica, Pseudomonas aeruginosa. Biosurfactants have several applications:
A)ANTIMICROBIAL ACTIVITY: Biosurfactants have strong antibacterial, antifungal and antivirus activity; these surfactants play the role of anti adhesive agents to pathogens making them useful for treating many diseases as well as its use as therapeutic and probiotic agent. A good example is the biosurfactant produced by marine B. circulans that had a potent antimicrobial activity against Gram positive and Gram negative pathogens
B)BIOSURFACTANT AS BIOPESTICIDE: Lipopeptide biosurfactants produced by several bacteria exhibit insecticidal activity against fruit fly Drosophila melanogaster and hence are promising to be used as biopesticide
BIOSYNTHESIS OF NANOPARTICLES BY MICROORGANISMS:
Variety of inorganic nanoparticles with well-defined chemical composition, size, and morphology has been synthesized by using different microorganism. Applications of biosynthesized nanoparticles i.e. inorganic nanoparticles including metallic nanoparticles, oxide nanoparticles, sulfide nanoparticles and other typical nanoparticles are used in drug delivery, cancer treatment, gene therapy and DNA analysis, antibacterial agents, biosensors, and magnetic resonance imaging (MRI).
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Q) How can we identify the bacteria on the product are present in the sample?
ReplyDeleteAns: The bacteria can be identified by disc diffusion method.The disk-diffusion agar method tests the effectiveness of antibiotics on a specific microorganism. An agar plate is first spread with bacteria, then paper disks of antibiotics are added. The bacteria is allowed to grow on the agar media, and then observed. The amount of space around every antibiotic plate indicates the lethality of that antibiotic on the bacteria in question. Highly effective antibiotics (disk C) will produce a wide ring of no bacterial growth, while an ineffective antibiotic (disk A) will show no change in the surrounding bacterial concentration at all. The effectiveness of intermediate antibiotics (disk B) can be measured using their zone of inhibition.
Q) Application of microbiology.
Ans: MAKING FASTER AND SMARTER COMPUTERS
The Archaeobacterium Halobacterium halobium grows in nature in solar evaporation ponds having high concentration of salts. Such salty ponds are found around San Francisco Bay located on the Western coast of USA.
It has been found that the plasma membrane of Halobacterium halobium fragments into two fractions, when the cell is broken down. These two fractions are red and purple. The purple fraction is important in making computer parts (chips). The purple colour is due to a protein which is 75% of purple membrane and has been referred to as bacteriorhodopsin.
The chips so made from the bacterial source can store more information than the conventional silicon chips and process the information faster more like a human brain. The only drawback is that one needs to store the protein chips at -4°C.
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DeleteThis comment has been removed by the author.
ReplyDeleteGrowth——A Matter of perspective
ReplyDeleteA population increase where each cell divides during a unit of time is termed as "exponential growth ".If the generation time of microorganism is 20 mins,then each cell will reproduce every 20 mins. this rate of population growth will continue as long as the organism remains in the exponential phase of a bacterium is relatively short. it can be limited by nutrient depletion, oxygen deprivation, the accumulation of inhibitory products, or other factors.
Suppose we devise a means for sustaining a culture of E. Coli
(Generation time 20 mins) in the exponential phase for 24 hrs?. What would be the no. Of progeny be?
A single bacterium would yield 4,722,366,478,574,681,194,496 cells.
They would weigh 4,722,366,478grms, which is 10,401,687pounds or 5200 tons.
Assuming the average weight of individuals in a crowd to be 160 pounds, this biomass would equal 65010 people.
Assuming that each cell is 2micrometer long, end to end they would stretch 9,444,732,957,149,362 meters or km.
Placed end to end, these bacteria would circle the earth 243,988,935times or stretch to the moon and back 12,459,009 times.
Utilizing glucose as growth substrate they would consume about 10,000 tons in 24 hrs.
Assuming the biomass to be a satisfactory food source, it would feed the entire population of North Carolina for one day.
NEVER UNDERESTIMATE THE POWER OF A MICROBE.
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Application of microorganism:
ReplyDeleteMycorrhizal fungi in agriculture:
Mycorrhizal plants show increased growth and are generally more tolerant of adverse conditions such as drought, soil pathogens, transplantation, poor soil nutrient status and soil pollution, compared to non-micorrhizal controls.
Improved plant growth and increased tolerance to adverse conditions can often be attributed to enhanced water and nutrient acquisition made possible by the extensive hyphal network which effectively increases the absorptive area of the root. However, the effectiveness of mycorrhizal fungi in increasing plant growth is not always directly related to the extent of root colonization or hyphal growth. In Eucalyptus globulus, plant dry weight was positively correlated with the length of mycorrhiza-colonised root for some species. In other cases, the benefits of Effective microorganism inoculation are more clear-cut and this approach has been used the establishment and growth of young transplant in horticulture and forestry e.g.Eucalyptus tereticornus, Acacia tortilis, Pinus species.
Interestingly, many of these beneficial effects are associated with a range of other phenomena such as mycorrhizal IAA and ethylene production and micorrhizal- mediated plant disease suppression. Black spruce, for example, is susceptible to the root rot fungus (Cylindricocladium floridanum).When tree seedlings were inoculated with the fungi Paxillus involutus and Hebeloma cylindrosporum, 50% of seedlings remained unaected by root rot.
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Sir nowadays we see many advertisements of bulbs that have antibacterial properties means they emit light at some frequency which is helpful to kill bacteria in surrounding. So do they not harm our skin because even bacteria are generally found on the surface of the skin. What are your views regarding that
ReplyDelete