A subdivision of microbiology dedicated to the study of bacteria.

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

I'd like to optimize the expression of a Fab fragment in Escherichia coli. For induction of the lac promotor on the pAK400 vector I use IPTG and sucrose. Do I optimize the expression in case I would ...
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56 views

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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What colony is growing on this petri dish? [closed]

I plated some stream water on agar and incubated the dishes at room temperature. I am curious to find out what the red streaks on the agar are. Is it E. Coli? Or is it some sort of fungus...
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29 views

Cleavage of RNA by restriction enzymes?

Six restriction enzymes discussed in this paper have the ability to detect and cut RNA strands with that enzyme's recognition sequence. As you know, restriction enzymes come from a system carried by ...
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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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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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Is it possible to express the cistrons from a polycistronic insertion fragment in a single plasmid?

I have a insertion fragment that I wish to express from pUC19 in Escherichia coli. The insertion fragment is a sub-section from a larger operon sequence and contains just the last two cistrons from ...
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17 views

Do aerobic bacteria precipitate in a liquid culture?

In most books aerobic bacteria is shown growing only at the top of a static liquid culture tube? Shouldn't have precipitated instead of floating on the surface?
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59 views

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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27 views

Heterocyst function in cyanobacteria and its localization

1.What is the function of heterocyst? 2.Where it is present? A heterocyst I think may be a protecting organ in cells!
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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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50 views

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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Are there mechanisms that limit the amounts of time conjugation and F-plasmid transfer can happen? If yes, what are they?

Not all bacteria have acquired F-plasmids through conjugation. Some of the mechanisms for this are unsuccesful conjugation events (mechanical disruption), no transfer due to integration in bacterial ...
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Why don't all bacteria have F-plasmids by now?

Some bacteria can undergo gene transfer by conjugation. Conjugation is a form of horizontal gene transfer, meaning from one (unrelated) bacterium to another (in contrast to vertical gene transfer, ...
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206 views

Why is E.coli used as a model?

Is there a reason for the choice of E.coli as a model for many bacterial systems? Other bacteria such as B.subtilis are also used, but why is E. coli preferred?
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33 views

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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73 views

Why do some bacteria have most genes on the leading strand of the genome?

Genes in the (+) strand are black and genes in the (-)strand are red. The gene distribution in E. coli genome is somewhat expected: transcribed regions would tend to alternate with non transcribed ...
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How long can Cholera bacteria survive in a dead host?

How long can cholera bacterium survive inside a dead host? Can they remain dormant in such conditions? BACKGROUND On a hill not far from where I live, there was a hospital operating since 16th until ...
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573 views

Why vaccines do not cause bacterial resistance?

Since bacteria can evolve to overcome antibiotic use, why wouldn't be able to evolve to overcome antibody or cell-mediated immunity? Thanks One possible explanation: antibiotics have only one target ...
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How can E. coli proliferate so rapidly?

The E. coli has a genome with approximately 5×106 bp. The main DNA polymerase involved in its chromosome duplication (DNA pol III , the one with highest processivity) can polymerize ~103 nucleotides ...
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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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281 views

Are bacteria necessary for an individual's life, or, how long could a person live without bacteria? [closed]

Bacteria are essential to life in that they are responsible for breakdown of organic substances, etc. but are bacteria necessary for an individual's life? In other words, how long would a human ...
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38 views

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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Can I use yogurt to prevent the growth of black mold?

I have a mold problem in my bathroom. There is a narrow groove between the top of my tub and the wall it is attached to where a black gunk repeatedly grows. I can shoot the material out with a spray ...
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What are the requirements for a stable carbon cycle in sealed “bottle gardens”`?

The most famous example of a sealed bottle garden is David Latimer's bottle with a Spiderworth plant, pictured below, which has been sealed for 40 years. My own attempt at a bottle garden is failing ...
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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 ...
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How to characterise a protein family in a putative genome island?

We have sequenced the genome of 200 bacterial strains belonging to the same species, a swine bacterial pathogen. In a previous work, it was observed that a protein family of adhesins is present in ...
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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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Does Pseudomonas aeruginosa have any common name at all?

Pseudomonas aeruginosa is the fifth most written about¹ binomial name of all species. I'm having trouble coming to terms with the possibility that such a well researched and studied organism has never ...
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How much of the weight of yoghurt is due to bacteria?

I recently started making all kinds of bacteria-processed foods by myself (such as yoghurt, but also Sauerteig and so on), and I found myself wondering how much of the weight of these products is ...
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44 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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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 ...
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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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Medium for Pseudomonas?

What is a good minimal medium for Pseudomonas bacteria? Do I need different media for different Pseudomonas species?
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Hot water and bacteria

I know that it is common to say, "use hot water when washing your hands" or when you've got a cut, "wash your hands with warm water," etc. I was wondering, why is this the case? Since bacteria grow in ...
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Can different strains of Rhizobium share an infection thread or symbiosome?

Rhizobium infection can be triggered at root hairs of legumes, creating infection threads. Can these infections threads be colonized by more than one type of Rhizobium (e.g. Fixing and non-fixing)? ...
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How to identify genes required for biofilm formation

This is just a homework question: Q: Let’s assume that there is an unknown set of E. coli genes that are required for biofilm formation. Describe a genetic experiment you could perform to try to ...
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What is the nature of plasmids? [closed]

What are the plasmids composed of? Are they composed of genomic or non-genomic DNA? I guess the answer is "genomic DNA" but I'm not sure.
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62 views

Are all single-celled organisms Bacteria?

I read that "Bacteria are one-celled organisms that can multiply by division", are all one-celled organisms bacteria or are there any more narrow definitions?
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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. ...
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Effect of flask position in shaking incubator affects growth kinetics

During some cultivation experiments for my bachelor thesis I noticed that in liquid culture my bacteria (E. coli) grew differently, according to the position in the shaking incubator. Because the ...
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1answer
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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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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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77 views

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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66 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.
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130 views

Does every wave length of UV kill bacteria?

Will every wave length of UV work for killing bacteria? So will UV A, UV B and UV C all work? Or will only the shortest of the three, UV C, work? Also, will the average UV lamp help against bacterial ...
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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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Why does botulinum toxin seem to be more dangerous to humans than to other mammals?

Various mammals seem to get away with eating parts of carcasses that we would prefer to not even touch, and that we assume will make us sick. Because of that, I assume botulinum toxin is more ...
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How does isopropyl alcohol disinfect less in higher concentration?

Isopropyl alcohol can be used as disinfectant. For increasing concentration of it in water, the effect as disinfectant increases, and then decreases again. Typical concentrations for use as ...
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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 ...