Questions tagged [microbiology]

Microbiology is the study of extremely small organisms. This includes organisms like bacteria, fungi, protozoa, and viruses.

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How do mutations of viruses lead to drug resistance?

For instance, after starting zidovudine monotherapy against HIV, resistance develops against the drug because of a point mutation in the RNA transcriptase enzyme to which the drug binds. So how does ...
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Pathogen Modeling Program - Cold chain - Is there any model that allows you to change temperature at different times?

I am trying to predict the CFU (Colony-forming unit) or bacteria population size across time. There are programs where you can modelate the growing of bacteria and its population size through time ...
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Using autoclaved store-bought distilled water for labwork?

I'm a high school student who's working on a molecular biology project in my school's lab. I need pure water for making culture media, buffers, running a BCA protein assay, running digests, cleaning ...
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What is the simplest way to demonstrate the germicidal property of UV light?

This is intended for a high school project. I am familiar with the one that studies growth of e coli over time in a petri dish but I a bit concerned about as to how safe a demonstration of this nature ...
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How is a bacterial strain defined?

When a species of bacteria is referred to by its strain, are they a clone of single founder or is a certain amount variation allowed?
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Bacterial Growth Formula

What are the units of $N$: the colonies of bacteria or the viable cell count? This is in regards to the bacterial growth formula used during serial dilutions, $$ N =N(0) e^{kt} \quad . $$
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Why does atrazine kill photosynthetic bacteria and not nonphotosynthetic bacteria?

Atrazine was found to bind to Qb, which is involved in electron transport to create ATP in photosynthetic bacteria. Why does this herbicide kill photosynthetic bacteria, while having little to no ...
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If someone were to die on the moon, would their body decay?

I heard that the footprints of Neil Armstrong are still there, so I was wondering if someone were to die there, would they remain preserved, too? If not how long would it take for them to decay?
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Ideas for microbiology lab. Antimicrobial properties of cutting boards

I am an undergraduate student in Biology and I am trying to design a microbiology lab that will takes 3 weeks to carry out (1-2 day each week). I am going to examine the antimicrobial properties of ...
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Can a pathogen be totally resistant to the human immune system?

Can a pathogenic organism be totally resistant to the human immune system? For the purpose of this question, the organism in question must cause a disease. Examples of organisms that would qualify as ...
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Why do yeast ferment Equal sweetener

I had my students conduct a fermentation experiment manipulating sugar amounts (number of sugar packets in solution) and measuring CO₂ production via capture in a balloon and measuring circumference (...
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Can anyone help identify these organism found in biofloc?

Can anyone help me with identifying what these organism is? It is found in my biofloc culture with shrimp Litopenaeus vannamei. I have been adding wheat as carbon source for my biofloc.
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Does more ATP present mean that a microbe can ferment more and decrease the pH? [closed]

I noticed that EMP produces 2 ATP and EDP produces 1 ATP. Does that mean that if more ATP is present that would give more energy for fermentation and lowering the pH of a system?
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Which culture media is suitable for cheek epithelial cells?

A month ago, I tried isolating cheek cells from saliva and the experiment was a success, however, I was wondering if it is possible to cultivate these cells in vitro. I'd say it's possible, but I wasn'...
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Can I sterilize the equipment for experiments without an autoclave?

If I don't have access to an autoclave, can I sterilize my equipment in a regular pot. If so, what time is needed at about 110°C (I measured inside) for a proper sterilization?
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Is iodised salt harmful to the lactofermentation process?

I was discussing sauerkraut recipes with someone on IRC a minute ago, and they warned me not to use iodised salt in the process. My first (and so far, the only successful) batch is one I made with ...
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Why should benzalkonium chloride (an antifungal agent) be used during your laundry machine's “rinse” cycle, not its “wash” cycle?

I'll first provide lots of background information. My actual question is at the very end. Background The spread of athlete's foot Athlete's foot is a fungal infection which is mildly contagious. ...
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1answer
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What is meant by Physarum polycephalum having 720 sexes?

There is currently some media hype about the slime mold Physarum polycephalum, which will soon be exhibited in the Paris zoo. This was my first time hearing about slime molds, but so far so good. ...
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Cleaning Masterclave

When i finish operation. My masterclave has smell, I think has media moulecular bind into the surface and microbial can live in. My labs don't have SOP to clean it. I promote use detergent but wonder ...
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Lecithin in Tryptone Azlectin Tween (TAT) media

When I made TAT in tank and separate in chamber, I found precipitation in some chamber, not at all. I asked my site manager and her tell me it's lecithin and normal. But, in my oppinion, I think ...
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Why is synthesis of tetanospasmin advantageous to C. tetani?

The tetanospasmin is a neurotoxin synthesised by some strains of C. tetani. It is the factor causing tetanus, but what is its role for the bacteria itself? I do not believe the main objective of C. ...
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Assessing in soil biodiversity of arid area of US

I am considering assessing the microbial biodiversity (using metagenomics) in the soil of an arid area of Utah (Hanksville) that has dinosaur and other fossil remains. 1) Could it be argued that ...
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How do I prepare a Basal medium for autotrophic mutant creation

Minimal medium (MM) was prepared by adding 2.0 g sodium nitrate (NaNO3) to 1 L of basal medium (BM) fol- lowing Correll et al. (1987). Chlorate resistant sectors (CRSs) were generated on two media i.e....
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Autoclaving media Question

1.When I autoclave media should I close the cap tightly or slightly? I put all tools in plastic bag when I autoclave, should I close slightly the plastic and when it finish I close tightly the ...
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Are most pathogenic bacteria facultative anaerobes?

I know that S. aureus and most gram-negative rods are facultative anaerobes. In terms of number of species, are most human pathogen-associated bacteria facultative anaerobes?
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How is Pseudomonas aeruginosa diagnosed?

I know that P. aeruginosa is cultured on an agar plate, but which media or assays make it distinct from other Gram-negative bacteria?
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How could be the concentration of airborne pathogens in a specific indoor space be measured?

I wonder if it is possible to measure the concentration of airborne pathogens in a specific indoor space in order to extract a percentage value. This value would be helpful to determine specific ...
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Is there a minimum load below which an infectious agent will not cause disease?

Suppose a single smallpox virus is injected in an human adult's body. Will it cause disease in the host? Is there a minimum microbial load below which it will not cause disease?
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What disease does Saccharopolyspora erythraea cause?

For an examination assignment I have to find a disease caused by the bacterial species Saccharopolyspora erythraea, but I have searched the internet and have found no report of patients being infected ...
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Does DHA increase the effects of clarithromycin?

I've read on this publication that every drug that induces CYP3A can reduce the effectiveness of clarithromycin. Clarithromycin inhibits CYP3A. But it does not say anything about the opposite ...
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What specific criteria do you use to choose E.coli strain for the experiments? What is the most standard strain?

For my specific case, I would like to know what plasmid to use to express two particular proteins (one of them being the GFP reporter) with its specific promoters. But more important than the answer ...
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E. coli & aspartate

I am familiar with the linkage between aspartate/ligand binding, receptor methylation, and flagellar behavior re. style of locamotion, but I do not know what the bacterium does with the aspartate it ...
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1answer
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Can exposure to blood make pathogens resistant to the immune system?

If a drop of my blood is dropped into a pool of pathogens. Does that act as "reverse-vaccination" for said pathogens? I see this it as a potential risk for bacteria/viruses to compete or get ...
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What happens to lactic acid I eat?

Let's say I drink some Kefir Milk, what happens to the lactic acid in the Kefir Milk that has entered my digestive system?
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Action of tetracycline on 30s ribosomal subunits

My question concerns the mode of action of 30s ribosomal antibiotc inhibitors — tetracyclines. According to some online resources, the antibiotics enter the A-site, which prevents other tRNA from ...
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1answer
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Growth rate oscillation in the a population of non-interacting bacteria

I have come across this theoretical paper claiming that if you start a batch culture from a single E. coli cell, the exponential growth rate of the population defined as $$k = \frac1N \frac{dN}{dt}$$ ...
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1answer
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Is bacillus strain 2-9-3 really 250 million year old?

I've read that in the last decade (I believe) some scientists discovered a microorganism, which they dubbed bacillus strain 2-9-3, in a crystal of salt that they think is 250 million years old and ...
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Diffussion coefficient of blood

What it the diffusion coefficient of blood in, e.g. water? It is needed for microchannel length calculations I have found a bit different nubmers: 0.94 and 1.66 microns^2/ms, but not sure
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Why do bulls-eye rashes look like they do?

People infected with Lyme Disease often present with an erythema migrans ("migrating redness") rash. Most often, these rashes are in the shape of a bulls-eye. Rash image. Presumably, this is a ...
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How can Valonia ventricosa cells get so big?

Valonia ventricosa are single-celled algae that range between one and few centimetres. In rare cases, they can reach sizes exceeding 5cm. They range from grass-green to dark green, and some are even a ...
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What is the effect of non-vaccinated people on vaccinated people?

Many times have I heard that anti-vaccine people are dangerous even to the vaccinated population. Is that true? If so, how can it be? People say that germs will attack them, and soon they would ...
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Is there any double staining method to visualise separate colour for plant tissue and fungal tissue?

Is there any double staining method for developing separate colour on fungal tissue and plant tissue when the said 2 types of tissues are intermingled? Unlike my previous question, this question not ...
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Can a vaccine or antidote be administrated via gases or sprays?

On TV or in movies a gas or spray containing a vaccine/cure/antitoxin is released and everybody is saved. Is this something plausible in real life? Specific examples would be appreciated.
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How DNA probe binds

I am studying about southern hybridization now and I've a doubt.After the DNA has been fragmented using restriction enzymes and obtained on nitrocellulose blot , it is still double stranded (the ...
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How do carbon 13:12 ratios confirm the biological origin of oldest microfossils?

I was reading this article about how Schopf and Valley’s findings in 2017 confirmed that the 3.5 billion–year-old microfossils found in the Apex chert of Western Australia are indeed remnants of ...
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how many spores are needed to “infect” a wall?

There's cardboard box in my room that used to be in another room that had mold all over the walls and it still smells moldy. This probably means the air in my room is polluted with mold spores.(right?)...
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Species diversity in cheese and yoghurt?

There have been studies on the number of species on humans and in various other environments. I was wondering how many species including: viruses, bacteria, yeasts, and fungi inhabit ordinary farm ...
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What makes an E.coli an E.coli, genotype or phenotype?

According to this paper, among 61 strains of E. coli they studied only 6% of the genes are common in all. Which means that the overwhelming majority of the genes are not shared. And wikipedia ...
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Why is glycerol supplied/used as 87% solution?

While preparing glycerol stocks of my transformed bacterial cells (DH5alpha) the protocol I had to follow was that I would make one 50% glycerol stock (500µl culture, 500µl glycerol 50%) and another ...

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