A subdivision of microbiology dedicated to the study of bacteria.

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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 ...
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Can general soap kill bacteria?

I have read that general soap can kill bacteria by opening holes in the bacterial membrane. http://questions.sci-toys.com/node/90 However, I found some articles as well saying that it cannot. ...
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Is episome a plasmid or a virus?

A plasmid is a small DNA molecule that is physically separate from, and can replicate independently of, chromosomal DNA within a cell. In general, in eukaryotes, episomes are closed circular DNA ...
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How does the immune system recognize pathogens?

There are useful and pathogenic bacteria in our body. How does the immune system differentiate between them?
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132 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 ...
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73 views

Extract bacteria from compost?

I'm working on a project where I need to find certain cellulolytic bacteria. I was looking at this list : ...
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169 views

What are the most important factors influencing a person’s gut microbes?

You are your bacteria! The probiotics and the antibiotics... There has been on going discussions about how our gut bacteria is important for a healthy lifestyle. Figure 1: Schematic diagram ...
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Why is knowledge of bacterial pathogenesis important? [closed]

Why is knowledge of pathogenesis increased more and more for common bacterial pathogens? Most of these studies lack a near application in disease control such as vaccines or antibiotics. Examples: ...
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70 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 ...
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437 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 ...
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63 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?
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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 ...
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Regulation of V. cholerae virulence factors

So I know that several different environmental signals, such as pH, bile, and temperature, regulate virulence gene expression in V. cholerae. Specifically, they control expression of the genes ...
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107 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 ...
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Are the intestinal microbiota substantially different within a diverticulum of the colon?

From the Wikipedia page for the vermiform appendix: This proposal is based on a new understanding of how the immune system supports the growth of beneficial intestinal bacteria, in combination ...
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80 views

What is the difference between a bacterial artificial chromosome (BAC) and a plasmid?

Is it just that a BAC is generally larger and artificially constructed? Or are there any other differences?
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How do I test if microbes have survived after dehydration?

I have a solution containing various bacteria and fungi. My aim is to place solution on filter paper, and wait until it dries. I then wish to test if the organisms have survived, either on the dried ...
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Generate T2/T1 Phage Resistant E Coli

I would like to generate T2/T1 phage resistant Stbl3 E Coli to use in virus production. Is there a plasmid somebody has used that confers resistance, or is this done another way?
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Can Helicobacter pylori be eradicated naturally?

This question is not to discuss whether substances that have anti-H. pylori activity work or not, or to discuss the pros and cons of such but from a medical perspective. Assuming that one is able to ...
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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 ...
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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 ...
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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!
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Does a microwave oven disinfect food?

Imagine I am preparing food, just about to put it into a microwave oven, and some of it falls on the floor. Assuming it got some bacteria or other organisms (viruses?) on it, will the microwave ...
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76 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 ...
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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 ...
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770 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 ...
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278 views

Do I need to serially dilute E. coli cultures for optical density measures?

I am expected to track cell growth by measuring the incubating culture's cell concentration every 30 minutes or so. So my questions are: Why do I need to do serial dilution (assuming that I do)? Why ...
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111 views

Why do bacteria need messenger RNA?

Why do bacteria need mRNA? Isn't the DNA free floating without nuclear membrane so why doesn't the tRNA read the code directly off of the split DNA strands? (ofcourse after helicase splits them). ...
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Cleavage of RNA by restriction enzymes?

Six restriction enzymes discussed in Sequence-specific cleavage of RNA by Type II restriction enzymes (Murray et al.) have the ability to detect and cut RNA strands with that enzyme's recognition ...
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Is [O2] different in a 5 mL liquid media?

Is there a drastic difference between top and bottom of the tube, with no stirring?
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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 ...
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241 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 ...
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81 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 ...
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86 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 ...
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51 views

How can E. coli affect C. elegans expression?

Plasmids can be transferred to E. coli. These transformed E. coli can be fed to C. elegans to silence its gene expression by RNAi. How can E.coli release RNAi to C. elegans? Even if we assume E. ...
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29 views

Do I have to use sucrose to induce a lac promoter?

I'd like to optimize the expression of a Fab fragment in Escherichia coli. For induction of the lac promoter on the pAK400 vector I use IPTG and sucrose. Do I optimize the expression in case I would ...
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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.
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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 ...
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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 ...
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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 ...
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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 ?
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How do minute changes in an organism, as a result of evolution, get carried over to next generation

Theory of evolution states that random variations in organisms occur to better suit their surroundings. We take for example a bacteria's flagella. There's a bacteria who has a tube kind of structure ...
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Why are plasmid genes not already incorporated into bacterial chromosomes if necessary for stressful situations?

If plasmids are important for bacteria to express specific genes under stressful conditions, why are these genes not already incorporated into their chromosome to begin with? What is the evolutionary ...
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What makes certain obligate anaerobes viable in fermentation starter cultures?

If Propionibacterium are obligate anaerobes (to wit, poisoned by oxygen), what makes 'Dairy' or classical propionibacteria (e.g. P. shermanii, P. jensenii, P. acidicpropionici, et al) viable in ...
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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 ...
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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.
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714 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, ...
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288 views

How much natural genetic variation is there between bacteria of the same species?

There are lots of questions about how and why there is genetic variation between organisms of the same species, but I haven't been able to find a numerical value for the expected amount of genetic ...
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Which strains of C. diphteria are causing Diphteria toxin?

I got this question: Diphteria toxin is produced only by those strains of C. diphtheria that have which of the following characteristics? Encapsulated glucose fermenters lysogenic for b-prophage ...
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Do adult humans exchange beneficial bacteria? If so, how?

Recently there has been increasing interest and research into symbiotic bacteria present in humans and human gut. I'm aware of two new discoveries: humans are surrounded by a unique cloud of ...