A subdivision of microbiology dedicated to the study of bacteria.

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What does NaOH do for the plating of Bacillus subtilis?

A book called Molecular Biological Methods for Bacillus called for plating Bacillus subtilis cells on LB-agar plates with the following components: A general-purpose medium containing per litre: ...
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What is the effect of antibiotic chloramphenicol on bacterial size?

When low amounts of antibiotics like Chloramphenicol is added in a bacterial culture, the steady-state growth rate decreases but what happens to the steady-state size? Can anybody please refer me to ...
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What is the mechanism by which bactericides kill bacteria? [closed]

"Bactericides kill bacteria". What is the meaning of "killing" in this context, and how exactly is this "killing" happening chemically?
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Decomposition Rate of A Body In A Wet Environment

I have a photo of a decomposing dog which is in a water logged environment. My peers and I are debating how long that body has been decomposing. They are saying it is at least a year old. I however ...
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Unsure why Synechococcus moves at angle in cuvette

I'd really appreciate your help. I'm working with Synechococcus. In my experiment, I have Synechococcus in a solution of milli-Q water. I illuminated it with a focused white light through a pinhole ...
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Is it possible to merge the genomes of photosynthesizing and electron-transporting bacteria to make an electric cell?

I had an idea of making electric current from bacteria. There are some bacteria that can photosynthesize, and some others are capable of transmitting electrons through each other. Is it possible that ...
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81 views

What are the evidence that all life today descended from a common ancestor (LUCA), and which organisms (if any) challenge the concept?

If I understand correctly, the concept of the LUCA (last universal common ancestor) is based on the hypothesis that archaea and bacteria share common ancestry. In the realm of mathematics, the same ...
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202 views

Approximately how long do bacteria live for? [closed]

I would like to know how many days or years do the bacteria live approximately.
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What bacteria do unborn babies contain?

This Scientific American article states that "[human] infestation [by bacteria] begins at birth". This would suggest that unborn babies are free from any bacteria. However, if the mother catches a ...
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Secretion in Gram negative bacteria

Among the 6 secretion systems in bacteria, can these 6 ways be sorted out in the order of how harmful it is to the human host? Like say type 3 is highly virulent so that comes first, but I don't know ...
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Requirements for soil sample transportation over long distance

I need to collected soil sample from agricultural area far away from my lab. It would required about a week for the sample to arrive to lab. I need the soil sample for genomic DNA isolation ...
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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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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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108 views

What concentration of table salt is needed to kill bacteria in sweaty gym clothes?

My gym clothes retain an unpleasant musk even after washing them with warm water and detergent. I've experimented with soaking my gym clothes in salty water before washing them. My hypothesis is that ...
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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 do some protocols require prewarming a liquid medium before inoculating?

For example, in this protocol for E. coli competent cell preparation, it says: Plate 10 uL E. coli BL21(DE3) cells on a LB-agar plate; incubate overnight (12 hours). Prepare 500 mL SOB medium ...
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What bacteria shed harvestable energy from root zone organic matter?

I recently heard of a successful effort that harvests energy from soil at plants' bases due to apparently bacterial breakdown of wastes from the plants: Via photosynthesis a plant produces organic ...
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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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Why pick just a single bacterial transformed colony

So after bacteria have been transformed to perhaps grow up a plasmid of interest, why pick only a single bacterial colony from a selective plate for further expansion? I understand that this is to ...
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Risks in bacterial phage therapy

I just finished reading J. Craig Venter's book Life at the Speed of Light: From the Double Helix to the Dawn of Digital Life. The book is a little over a year old now, and Venter has an optimistic ...
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What is the difference between an antibiotic and an antibacterial?

Concerning medicine, what are the differences between antibiotics and antibacterials?
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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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How to obtain bacteria samples at home?

As the original question went from hold to closed, I thought I would write up a more appropriate question. How should one go about getting bacterial samples to look at under a microscope at home? ...
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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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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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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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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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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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Does antibacterial soap work chemically?

Normal soap requires scrubbing, does anti-bacterial soap require scrubbing too? Since it (I assume) works chemically, can I produce the same cleansing effect without lathering with soap and using ...
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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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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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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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Why are pili more common in Gram negative bacteria than in Gram positive?

Although pili have been observed in some species of Gram positive bacteria, the preliminary research that I have done indicates that pili are significantly more common in Gram negative bacteria. Is ...
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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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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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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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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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133 views

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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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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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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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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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 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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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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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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Are there grass or fiber eating birds?

My understanding, that may be wrong, is that cellulose/fibre has little nutritional value to many animals because it's hard to break down thus making consumption inefficient. However, Ruminating ...
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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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68 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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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 ...