A subdivision of microbiology dedicated to the study of bacteria.

learn more… | top users | synonyms (1)

5
votes
2answers
58 views

Flow cytometry issues

I'm having problems with data analysis here. I have flow cytometry data being collected on a Fortessa, and when I import them into FlowJo 8.7, all of my fluorescence values are systematically 10X ...
5
votes
1answer
132 views

Mutation-immunity in Luria-Delbruck experiment

If experiments like those of Luria and Delbruck on E. coli and T1 phage are the main source of our confidence in the mutation-immunity model, is it then highly unlikely that there are other types of ...
5
votes
1answer
829 views

How does heat shock transformation work?

What exactly happens when competent cells like DH5ɑ are heatshocked with DNA present? How does the DNA get inside the cells? Specifically, why are all the steps necessary? What if you heatshock right ...
5
votes
1answer
107 views

Is 1 g/l living biomass for a Biogas fermenter plausible?

A usual number for a healthy biogas fermenter is $10^9 - 10^{10}/mL$ Bacteria, 10-15% of which would be methanogenic archae. Exceptionally healthy fermenters have more total bacteria and up 25% ...
5
votes
2answers
512 views

Sparking during electroporation of plasmid DNA into bacterial cells

During electroporation of bacterial cells (I work with Mycobacterium tuberculosis, but I think this applies to E. coli as well), sometimes I get sparking. I've read this is due to salts present, ...
4
votes
3answers
278 views

What is the mechanism of oxygen uptake in E. coli?

How does E. coli uptake oxygen? Most of the literature I found is concerned with response to oxygen level supplied in the medium, as opposed to how much is actually transported inside. Can they shut ...
4
votes
2answers
193 views

Gas from bacteria that's not methane

Is gas produced by bacteria always mainly methane? Or, are there bacteria out there that produce some biogas composed mainly of hydrogen, natural gas, propane, butane?
4
votes
1answer
76 views

Blood consumption

Is consumption of blood more "dangerous" compared to meat? There was a news-article about unnatural chemicals found in the blood of mothers. This reminded me about a question I have pondered upon ...
4
votes
1answer
51 views

Correlating beta-lactamase expression to absorbance

When penicillin-resistant bacteria are grown in liquid culture media, β-lactamase is secreted into the medium. The supernatant of such a medium can be assayed for β-lactamase activity. ...
4
votes
2answers
450 views

Does making yogurt from non-pasteurized milk work against possible disease bacteria?

In the past, when there was no pasteurization, could making yogurt from milk lower the chance of getting infected by bovine tuberculosis (or other diseases from infected milk)? For example, would ...
4
votes
1answer
57 views

How often does bacterial transformation happen?

I have been reading: M. Dröge, A. Pühler, W. Selbitschka, "Horizontal gene transfer among bacteria in terrestrial and aquatic habitats as assessed by microcosm and field studies", Biol. Fertil. ...
4
votes
1answer
55 views

Is there any way the food industry can benefit from biofilms?

I realize all of the disadvantages, but I am wondering if the food industry can actually benefit from the formation of biofilms.
4
votes
1answer
359 views

How do I measure bacterial growth in agar dishes (either by cell mass or by cell count)?

I am doing an experiment in which I am growing S. mutans in agar dishes, and I am not sure how I would measure the growth of the S. mutans. I am also not sure if I would do this by measuring cell mass ...
4
votes
2answers
88 views

Why do plasmids replicate on their own?

I know how plasmids can replicate independently of the main genome and know that they confer various properties to the bacteria and are useful in conjugation. My question is - what is the advantage ...
4
votes
1answer
40 views

What microscope/magnification would I need to observe P. Acnes bacteria?

I am currently attempting to grow a culture of P. Acnes bacteria. Right now, my only hope in identifying colonies of the bacteria in the culture is to use a black light to find colonies that glow ...
4
votes
1answer
128 views

Does conjugation support gene selection?

I have already posted this on chat but haven't got any response. A recent question on group selection stimulated me to ask this here. QUESTIONS: Why should bacteria conjugate? If we consider that a ...
4
votes
1answer
67 views

How can I save bacillus strains on filter paper without an -80 degree freezer?

I want to save my bacillus strains but I don't have access to a -80 degree freezer. What are possible alternatives?
4
votes
1answer
144 views

What is the length of anaerobic biodigestion stages?

I have built an experimental portable batch biodigester to process organic garbage. A 50L drum filled half with garbage, half with water and with some cow dung added for inoculation, is connected from ...
3
votes
2answers
592 views

What are gram negative and positive bacteria?

I've just finished a course of double antibiotics for Helicobacter pylori in my stomach. I looked up H. pylori and found that it was a gram-negative bacterium. I looked up gram-negative and didn't ...
3
votes
2answers
153 views

What is a bacterial biofilm?

Bacteria produce something called a biofilm. I have found a few definitions; some say it is a complex of live and dead bacteria and others say it is a layer on cell wall. What is it made of? What ...
3
votes
2answers
44 views

What does the gene name “lexA” stand for?

It is an important gene expressed in E. coli that represses the SOS response and also the expression of lambda lytic phase genes. UV light and damage to DNA is responsible for its breakdown and hence ...
3
votes
2answers
96 views

How long can C. Tetani survive in soil?

Clostridium tetani (C. tetani) is a bacterium commonly found in soil and is excreted in the faeces of many animals (both mammals and birds) and serves, by means of the exotoxin, tetanospasmin, causes ...
3
votes
3answers
113 views

Restriction endonucleases are found in?

Quoting from : Scientific American July 1975 The Manipulation of genes by Stanley Cohen : Restriction endonucleases (and modification methylases) are widespread in microorganisms; genes for ...
3
votes
1answer
88 views

When might an inhibitor of bacterial transformation be useful?

I am part of a project elucidating some structures that are required for bacterial transformation. We have the opportunity to screen inhibitors of the system to stop it from functioning. I am not a ...
3
votes
1answer
31 views

Survival of streptococcus after my scarlet fever

I'm currently sick because of scarlet fever but I got treated with antibiotics. I know that after 1.5 day using antibiotics the streptococci I release at home are dangerous anymore. But my question ...
3
votes
1answer
136 views

How does sucrose protect bacterial cells in lysozyme solutions?

I have a microbiology question. When we put bacterial cells in sucrose solution with concentration higher than 0.5M we observe plasmolysis - the cytoplasmic membrane detaches from the cell wall due ...
3
votes
1answer
50 views

What is the film that covers the tongue?

What is the film that covers the tongue in the mornings, even after brushing the teeth and tongue the night before and why does it have color variations? Do the different colors mean anything?
3
votes
1answer
31 views

Functioning of BCG vaccine

I read (from Nature Volume507, S4–S7 (06 March 2014) : For reasons that are poorly understood, BCG protects only infants; it is ineffective in older children and adults. Its efficacy also ...
3
votes
1answer
44 views

Could the growth rates of Vibrio vulnificus be affected by an oil spill?

I live on the Gulf Coast, and Vibrio vulnificus has recently made the news due to an increase in the number of reported infections. Naturally, it has people around here worried. I live in an area that ...
3
votes
0answers
33 views

Do sulfate reducing bacteria help during the formation of the mineral dolomite in low temperature environments?

Do sulfate reducing bacteria help during the formation of the mineral dolomite in low temperature environments? Wikipedia says The actual role of bacteria in the low-temperature formation of ...
3
votes
0answers
115 views

Cheapest Way to Measure Germ Density

I would like to measure the surface density of Staphylococcus bacteria and Rhinoviruses (only those two, to be specific) within my home. What's the cheapest way? The textbook procedure is to: rub ...
3
votes
3answers
73 views

Is there a specific word for bacterial death?

What do you call it when a bacterium dies? Cellular death is apoptosis, necrosis, and bacterial is ...? I don't simply want to write in a paper that it - well dies!
2
votes
3answers
115 views

How quickly is antibiotic resistance lost?

I would imagine the bacterial genome is highly conserved and limited in its space, but maybe I am wrong. If you were to take a strain of antibiotic resistant bacteria and kept them isolated, but fed ...
2
votes
2answers
57 views

Why isn't Bubonic Plague as virulent as it once was?

Although I am admittedly not anywhere near an expert on any topic, I still have a hard time understanding how Black Death and Bubonic plague are one in the same. Since plague still exists, with news ...
2
votes
1answer
7k views

Why are bacteria and archaea in different domains?

As I understand it, the main difference between the Bacteria and the Eucaryota domains are that eukaryotes have a nucleus and bacteria don't. I understand that bacteria and archaebacteria have enough ...
2
votes
1answer
523 views

Why does ampicillin in solution turn yellow?

I have a universal tube with 10 mg mL-1 ampicillin. When I got it, it was supposed to be sterile. It was opened for approximately 20 minutes for an experiment and has since been standing around sealed ...
2
votes
3answers
113 views

Can antibiotic resistant bacteria compete with normal one in an antibiotic free environment?

The question is based on an intuition that antibiotic resistance can't come along. This mutation will probably make bacteria less tenacious. Is there any research how AR bacteria compete with normal ...
2
votes
3answers
1k views

How do a viruses or bacteria survive outside the body long enough to spread?

Say I cough on my table, then someone else touches it and picks up something I've got... how is it that these things can live outside the body, how long can they manage it, and how long is generally ...
2
votes
1answer
69 views

Aside from cockroaches and other insects, which species (of all kinds) are 'immune' to ionizing radiation?

I have just been reading this excellent question and answer about cockroaches ability to withstand ionizing radiation. My question is an extension of that question: aside from insects, which other ...
2
votes
1answer
76 views

Whence fecal E. coli (et al.) if swallowing it is dangerous?

I don't know much about medicine, and I know even less about microbiology, but I understand that there are organisms in the lower gastrointestinal tract (and in feces) of a human, like Escherichia ...
2
votes
1answer
35 views

Do bacteria with multiple flagella move faster than bacteria with a single flagella?

Do bacteria with multiple flagella move faster than bacteria with a single flagella? Assuming the flagella are at the same length.
2
votes
1answer
69 views

Production of processed Insulin in bacteria

Genetically-engineered bacteria are used to produce insulin in industry, but as far as I know, the bacteria can produce only proinsulin. Why is that? What happens in the human body in order to make ...
2
votes
1answer
39 views

Are added yogurt cultures harmful to the gut?

I have read somewhere that the live culture added to yogurt acting as "healthy" gut bacteria are actually synthetic and harmful. Any truth to this? If so, what are some alternatives to getting good ...
2
votes
1answer
50 views

Quorum Sensing in Vibrio cholerae

This is a figure summarising the quorum sensing mechanism in Vibrio cholerae. In this video by Bonnie Bassler, she explains how quorum sensing can be targeted to control infections. At 15:09 she ...
2
votes
2answers
3k views

Why restriction enzymes cut (usually) at palindromic sequences?

Restriction enzymes usually cut only at palindromic sequences. Is there any specific reason for that ? Is there any advantage for bacteria if it cuts up virus at this type of sequences ?
2
votes
1answer
23 views

Medium for Pseudomonas?

What is a good minimal medium for Pseudomonas bacteria? Do I need different media for different Pseudomonas species?
2
votes
1answer
91 views

Do lysogenic viruses only infect bacteria?

In the video sent by my teacher on viruses, the example he used for lysogenic viruses was a bacteriophage infecting a bacteria. When he was describing how the genetic material was incorporated into ...
2
votes
1answer
59 views

Speciation and Phylogeny of Lactobacillus

The lactobacillus, also called Döderlein's bacillus is a genus of facultative aerobic bacteria. There are several species such as Lactobacillus acidophillus and Lactobacillus reuteri. I have several ...
2
votes
1answer
57 views

Why is Thermus aquaticus and Taq Pol stable?

What is the molecular basis of the stability of the bacterium Thermus aquaticus and the enzyme Taq Pol it produces ? I have tried googling this but did not get a good answer.
2
votes
1answer
268 views

Mesosome - does it exist?

This wikipedia page says that mesosomes are artifacts produced by chemical fixing techniques. Most of my textbooks still show a mesosome and describes it as having functions like - respiration, ...