A subdivision of microbiology dedicated to the study of bacteria.

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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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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 ...
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71 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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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 ...
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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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45 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.
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88 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 ...
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42 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 ...
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128 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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60 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 ...
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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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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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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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62 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.
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339 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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249 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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63 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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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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Horizontal Gene Transfer

I understand the different ways bacteria can undergo horizontal gene transfer (transformation, transduction (phages), conjugation (plasmids)). Is there an experimental method to tell how a specific ...
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Will an 11W UVC lamp kill bacteria?

If I shone a UVC lamp (11W) on something (say for example a plastic phone case) for an hour, would that kill off a noticeable amount of bacteria? That is, if I were to go over the case with a cotton ...
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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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Aerobe or facultative anaerobe organism that metabolizes acetate?

I'm assuming bacteria, but will take any suggestions. Organism must survive primarily on the acetate (plus trace elements), but I can give/take electrons, if necessary. Not interested in strict ...
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Have there been any experiments that duplicate chromosome copies from 23*2 to 23*3 or 23*4?

Deinococcus radiodurans is an amazing bacterium with a fantastic survival rate. It can survive to high doses of radiation, in a complete vacuum and in hydrochloric acid. How does this bacterium ...
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Were we able to create vitamin B12 in past?

All herbivores produce vitamin B12 de novo. Gorillas, for example, are "vegans" so I suppose some human ancestor was also herbivore. Have we ever been B12 self-producers? If so, why have we lost that ...
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eradicating h.pylori naturally

This question is not to discuss whether substances with anti-h.pylori agents works or not, or the pros and cons of such but from a medical perspective. Assuming that one manage to control, reduce, or ...
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Can two Hfr strains of E. coli conjugate?

Genetics textbooks (and some internet searching) yield abundant examples of Hfr strains conjugating with F- cells, but these sources are surprisingly silent regarding the results of an Hfr ...
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Can diseases be transmitted wirelessly? [closed]

According to the recent research about Electromagnetic Signals from Bacterial DNA (A. Widom, J. Swain, Y. N. Srivastava, S. Sivasubramanian) it seems there is a possibility of a "wireless" version of ...
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Transportation of bacteria

I would like to take an apparatus containing bacteria to another country (Bolivia) from the U.S.. How do I determine whether I am allowed to do this? The bacteria are: ...
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College Bio Research: Bacteria found on computer keyboards. [closed]

I am a college students brainstorming ideas on different topics that may be appropriate for on-campus research. What I came up with and I would like to give it a try is analyze the different types of ...
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Image Processing Suite for bacterial microscopy: Schnitzcells or MicrobeTracker?

I am looking to start doing some work tracking the size and growth of individual bacterial cells in the microscope. In order to analyze the images I need software that can segment the cells, ...
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Are the intestinal flora 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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Functioning of EDTA

I know that EDTA chelates metal ions. It weakens bacterial cell wall and inactivates the DNases. What is the reason why it can do so ? I guess it can inactivate DNases by altering the ...
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173 views

List of all reported bacteria

I would like to know were to download a table file with all reported bacteria and its corresponding PHYLUM, CLASS, ORDER and FAMILY. Basically, its the same table than this one from GOLD genomes but ...
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What are the dimensions in angstrom of bacteria? [closed]

I'm going to take a picture of a bacteria but I am unsure how large it is. What are the dimensions in angstrom of bacteria?
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Buy bacteria for experiment?

Where can I buy paracoccus denitrificans? I need it for an experiment. I cannot find online where I can purchase this.
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What are the differences between G+ and G- bacteria?

The distinction between Gram-positive and Gram-negative bacteria is based upon the Gram staining method, that reflects the bacterial wall physical properties. However, this classification involves ...
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230 views

Why does beta-2-Thienylalanine inhibit bacterial growth?

I'm trying to obtain a better understanding of the Guthrie Test, which checks whether people have a disease called PKU. The Guthrie test uses bacteria to check for Phenylalanine (the amino acid) in ...
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How effective are restriction enzymes in protecting bacteria?

Bacteria use restriction enzymes to cut DNA of bacteriophages. Virus mutates really fast. Won't a point mutation in restriction site render the restriction enzymes of the bacteria useless ? So how ...
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Can Hepatitis be caused by Bacteria?

There are many information about viral hepatitis. But it is interesting for me, can bacteria cause the hepatitis too?
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To what extent is it possible to understand if a bacteria can produce a protein? (in silico only!)

I have to answer a question about a sub-task of my thesis: Can the bacteria X produce the protein Y? I searched of course Google and BLAST. There is no data supporting that this specific bacteria ...
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72 views

Why do peas change colour?

I am doing an experiment on preservation of peas. The first notable change to the peas over a period of one week is that they have changed colour from bright green to a dull colour... Why is this ...
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Expression of plasmid genes

Are plasmid genes always expressed? If so, then isn't a bacterium wasting it's resources in expressing genes (like antibiotic resistance) which are not required in "normal" conditions? If not, then ...
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How do plasmids protect themselves against restriction enzymes?

How do plasmids protect themselves from restriction enzymes released by bacteria (i.e., against bacteriophages)?
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Can viruses protect themselves against restriction enzymes?

Restriction enzymes cut the DNA of bacteriophages. Have bacteriophages evolved any mechanism to protect themselves from it ?
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Do toxin producing strains of E. coli constantly produce toxin or only under certain conditions?

Background E. coli is prevalent everywhere but only some strains produce toxins harmful to humans, such as E. coli O157:H7. Questions 1) Would anyone know if these strains are always producing ...
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132 views

What is the fastest growing bacterium?

E. coli has a generation time of about 20 min, and a single CFU will generate a colony a few millimeters in diameter after 16 hours of incubation. Is this the upper limit? How much faster can ...
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Are efflux pumps mutations or are they originally present in N. gonorrhoea?

I'll start by saying that I am no biologist. I am a math major trying to create a mathematical model for gonorrhea strain competition. My assignment is to create a model similar to a model that was ...
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164 views

Bacterial Conjugation/Horizontal Gene Transfer — how does the plasmid exchange work?

So according to a PPT I'm reading, bacterial conjugation works by the two bacteria joining pili and exchanging plasmids. So how exactly do the plasmids get across the gap? If I understand this ...
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Correlating Ki values of pesticides to bacterial growth

Four pesticides P1 to P4 are reversible inhibitors of an enzyme E that is essential for the growth of a bacterium B. Their Ki values are given in the table below. Each of these four pesticides ...