A subdivision of microbiology dedicated to the study of bacteria.

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What is the advantage of circular DNA in bacteria?

From what I understand, bacteria have circular DNA. What advantages does it have over linear strands like for eukaryotes? Do there exist bacteria with more than one ring of DNA?
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If a human takes antibiotics are all bacteria in the body killed?

From my basic understanding, antibiotics kill living things, bacteria for example. Do the antibiotics consumed by a human-being distinguish between what they kill? Or do they just kill every bacteria ...
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Why is there now only one Salmonella species?

Once upon a time, I chanced upon an old microbiology book that detailed the rather colorful world of enterobacteria. Salmonella in particular stood out, as it seemed there were a lot of species: typhi ...
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3answers
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What causes the development of antibiotic-resistant strains of bacteria?

I understand bacteria have become resistant to antibiotics due to selection pressures, but how do resistant bacteria process antibiotics when exposed to it, compared to non-resistant bacteria. Also, ...
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1answer
3k views

Why does Penicillin only affect bacterial cell walls

I was quite fascinated by the feature Should Science Pull the Trigger on Antiviral Drugs—That Can Blast the Common Cold? in this month's Wired magazine. They explain that Penicillin is effective at ...
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How long can E. coli stocks be stored at -20°C?

I'm volunteering for a biohacker lab - biocurious in Sunnyvale. The have a pretty good set of equipment - gel boxes, incubators, but they don't have a -80°C freezer yet. I'd like to set up some ...
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2answers
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What is the advantage of using starter cultures for growing bacteria?

Many DNA isolation and protein expression protocols contain instructions to use a starter culture of E. coli that is then used to inoculate the main culture. What are the advantages of using starter ...
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140 views

Is there an equivalent to “Fields Virology” for Bacteria?

I've gotten a staggering amount of use out of my copy of Fields Virology as a general reference for "getting me up to speed" on whatever pathogen I'm currently looking at. I don't know of a similar ...
10
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1answer
164 views

What are the functions of magnetic bacteria?

I'm trying to understand why are bacteria "equipped" with magnetosomes and why/what for do they need such organelles.
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123 views

What advantage would the initial 'donor' in horizontal gene transfer by conjugation have received?

I am struggling to think why horizontal gene transfer between bacteria would have persisted during the course of evolution as surely it puts the 'donor' at a disadvantage? For example, consider a ...
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129 views

Are these Gram stain substitutions acceptable?

In the context of a Gram stain on a blood smear: Are the following acceptable substitutions and/or what differences could arise by substituting them? Using methylene blue instead of crystal violet ...
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416 views

Which bacteria have the highest mutation rate?

From my reading on M. tuberculosis, I know that this organism has a pretty high mutation rate due to uncorrected sloppy replication, which leads to a high rate of development of spontaneous resistance ...
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312 views

Where do the bacteria within the vagina originate from?

I understand that it's feasible the bacteria within the gastrointestinal tract originate from the food we eat and air we breath, but where does this population of microbes originate from?
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465 views

How are antibiotic resistant bacterial infections treated?

For example, how are infections of antibiotic resistant strains of MRSA, Streptococcus, or Gonorrhea treated?
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271 views

Do antibiotics attenuate immune response on subsequent exposure to same bacteria?

A healthy immune response to a bacterial infection includes "memory" to permit the body to thwart subsequent exposure to same bacteria. What are the dynamics of using antibiotics on initial exposure ...
7
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1answer
5k views

How do prokaryotes perform cellular respiration without membrane-bound organelles?

In order to survive, prokaryotes such as bacteria need to produce energy from food such as glucose. In eukaryotic cells, respiration is performed by mitochondria, but prokaryotic cells do not have ...
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2answers
720 views

Bacterial cell lysis - what solution to use?

I am trying to determine how quickly detergents act on bacterial cells (cell lysis). I would like to compare some detergents at difference concentrations for bacteriolytic activity. I don’t care about ...
7
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1answer
311 views

How is the exogenous DNA protected from degradation during bacterial transformation?

During transformation, a bacterium can take up DNA from its environment. A small fraction of bacterial species are known to be naturally competent, meaning that they can engage in this sort of ...
6
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2answers
194 views

How do infectious bacteria know when their numbers are high enough to attack a host?

When you get sick, you generally don't contract enough bacteria at once for them to succeed in battling your immune system, right? Their numbers must gradually increase in the host's body before they ...
6
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1answer
525 views

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? ...
6
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1answer
206 views

Alternatives to CFU plating for measuring number of viable cells?

I am hoping to measure growth rates of a bacterial culture in several growth conditions. I am concerned that these growth conditions may cause cell death, which would lead to a decreased ...
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199 views

How Sex Evolved ? and when?

As I know evolution comes bit by bit mutation by mutation How sex evolved which requires a major change in at least two individuals one to become male and one to become female ? When that happened ...
6
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1answer
156 views

Whole genome amino acid composition tool?

I'm interested in a statistical tool to get bacterial codon usage at genomic level. Ideally, the tool should be flexible to analyse hundreds of bacterial genomes. I've looked in MeSH terms database ...
6
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1answer
175 views

Is there a detectable amount of bacterial DNA in the blood of infected persons?

With which bacterial infection in humans has it been shown that bacterial DNA can be found in the blood? If any is found it is likely not to be very much, and even difficult to distinguish from ...
6
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1answer
91 views

Proteins that are strongly overproduced in E. coli and S. cerevisiae?

I'm looking for some pointers to proteins that produce at really gigantic levels in E. coli and yeast (S. cerevisiae). Can anyone point to some champion proteins? Even in inclusion bodies and non ...
6
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2answers
132 views

What would cause E. coli to change from filamentous growth to normal growth?

In my lab we've observed a phenomenon in which a culture of E. coli is found to shift from normal rod growth to filamentous growth and then back to normal rod growth again several times over the ...
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4answers
382 views

What is the advantage of restriction enzymes cutting only at specific sites?

Bacteriophages have sequences which often do not have specific sites for restriction enzymes of bacteria to cut at and so can attack the bacteria. Wouldn't it be better if bacteria had something ...
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3answers
14k views

What is the difference between an antibiotic and an antibacterial?

Concerning medicine, what are the differences between antibiotics and antibacterials?
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1answer
260 views

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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1answer
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What is the distinction between F' plasmid and R plasmid?

Is there a difference between an F' plasmid that has taken up a chromosomal gene that conveys antibiotic resistance, and an R plasmid? Is a bacterium containing an R plasmid and yet lacking an F+ ...
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2answers
424 views

Possibility and feasibility of producing designed antibodies with bacteria

As stated here it is possible to produce fragments of antibodies in bacteria and harvest them (from the medium, I guess, but I don't have access to the full article). As it is possible to design ...
5
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1answer
133 views

Is there a practical upper limit to amount of nucleotides or genes in a transformed plasmid?

I'm currently working on a synthetic biology project which involves working with lots of different parts. I would ultimately like to integrate these genes by transforming a single plasmid. I've heard ...
5
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1answer
91 views

How can promoter binding sites be determined?

I have been trying to find out which sigma factor is responsible for the transcription of RNA polymerase subunits $\alpha$ (rpoA) and $\beta ^{\prime}$ (rpoC) in Bacillus subtilis. I would expect it ...
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1answer
979 views

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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1answer
293 views

Aren't antibiotic resistant probiotics dangerous?

Multidrug resistant probiotics are often recommended by doctors in various cases. But since bacteriae can easily exchange genes by conjugation or other means they could promote the drug resistance of ...
5
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1answer
150 views

What effect do oligosaccharides, like those found in legumes, have on the composition of intestinal flora in humans and if so how so?

I know that intestinal flora metabolising oligosaccharides, like those found in legumes, is the cause for the well known fact that legumes cause flatulence, but does an oligosaccharide-rich intestine ...
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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 ...
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1answer
113 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
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1answer
61 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
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1answer
102 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% ...
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365 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, ...
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1answer
521 views

Why do different bacteria have different shapes?

Why do different bacteria have different shapes? Is it only related to their function?
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4answers
98 views

How to measure bacterial content

I´m using water container placed on a radiator to humidify room air. Someone might argue that it is a perfect nest for bacteria. I have to put copper coins into the water to kill the bacteria. I ...
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2answers
164 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?
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367 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 ...
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2answers
1k views

Why would taking antibiotics increase stamina and energy?

I often hear that people who are taking antibiotics experience wild fluctuations between feeling full of energy and completely alert but soon after feeling impossibly fatigued and sick. Does this ...
4
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1answer
94 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
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1answer
63 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?
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351 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 ...
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2answers
121 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 ...