Questions tagged [bacteriology]

A subdivision of microbiology dedicated to the study of bacteria.

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1answer
86 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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168 views

Test of antibiotic A for sensitivity as surrogate of antibiotic B

I am reading the WHO Global Antimicrobial Resistance Surveillance System (GLASS) - Manual for Early Implementation. it mentioned some of the drug-bug combination that will be put under surveillance in ...
4
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1answer
176 views

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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I found this in my refrigerator water filter. Is it a biofilm? Is it a sign of dangerous bacteria?

When I dispense water form my refrigerator after changing my filter, the following slimy tube like deposits appeared. Does anybody know what this is? Could it be a biofilm growing in the water hose, ...
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316 views

Why a particular species of bacteria give rise to particular type of colony? [closed]

Bacterial colony varies in form, elevation, margin, opacity, chromogenesis etc. What gives definite character to a colony and what is the source of all the diversity? Is the reason similar to that of ...
4
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1answer
115 views

Decomposition Rate of A Body In A Wet Environment [closed]

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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568 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 ...
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3answers
307 views

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 ...
3
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272 views

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 ...
3
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85 views

Is it possible to prove that a hand sanitizer can kill 100% of a person's germs?

We have a project for Economics, and we need to advertise something that consumers will be willing to buy. My group thought of "improved" hand sanitizer. So, instead of it killing 99.9% germs, we ...
3
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277 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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175 views

Why is cancer more lethal than (hypothetical)infections?

I am a computer science student and I'm interested in algorithmic aspects of cancer! Once I heard that there exist more bacteria in human body than our own cells, I wondered that why bacteria, which ...
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913 views

Is iodised salt harmful to the lactofermentation process?

I was discussing sauerkraut recipes with someone on IRC a minute ago, and they warned me not to use iodised salt in the process. My first (and so far, the only successful) batch is one I made with ...
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182 views

Do bacteria with flagella self-rotate?

The bacterial flagellum uses rotation for generating forward motion, just like a helicopter main rotor does. Helicopters must utilize a secondary rotor to avoid self-rotation due to preservation of ...
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222 views

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 ...
3
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2answers
142 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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12k views

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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118 views

To what extent can bacteria actually see?

I found some popular articles (e.g. nbcnews and iflscience) that bacteria can "see," but I highly doubt it's in the same way as people do just from looking at the limitations in the vision of small ...
3
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68 views

Do sulfate reducing bacteria ingest their sulfate as solid, or as dissolved in water?

Do sulfate reducing bacteria ingest their sulfate as solid, or liquid or gas? I understand that almost all forms of sulfate are solid.. and sulfate can be dissolved in water(thus no longer solid, but ...
3
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84 views

How do parasites “reprogram” brains?

Dicrocoelium dendriticum is a parasite that uses ants as a second intermediate host (which means that ants aren't its primary host/target, but are rather a temporary host to help reach their main/...
3
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1answer
38 views

How long can Legionella survive at 60°C?

I'm coding some stuff for water heaters and one of the functions is anti-Legionella. Anyway, I've read on wikipedia that 90% Legionella dies in first two minutes if the water temperature is 60°C, but ...
3
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1answer
209 views

What causes Pseudomonas fragi to smell sweet?

I am working with Pseudomonas fragi and I could not help but notice that it smells sweet, which probably explains its species name 'fragi' from 'fragum', strawberry in Latin. Does anybody know what ...
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2answers
606 views

Are bacteria incapable of producing cytokines such as interleukins?

As far as I understand, bacteria cannot produce cytokines such as interleukins. However, I have not read an explanation as to why they cannot. Perhaps it has to do with an evolutionary limitation. Yet,...
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96 views

What is a catalytic domain?

I have to answer a few questions from an article I'm reading, and I am just really confused on defining "catalytic domain." I have to relate it to the antibiotic Teixobactin. Is catalytic domain the ...
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94 views

If a bacterium had a protein on its surface that humans also have, would it cause an autoimmune disease?

Suppose that a bacterium happened to have a protein on its surface. This protein can also be found in the human body. If this bacterium were to then infect a human with an otherwise normal immune ...
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Why do bacteria use formylated methionine in the initiator tRNA, while eukaryotes do not?

Could anyone suggest an explanation for the evolution of this trait in bacteria? Does it confer any advantage? It is also exploited by immunity receptors of some eukaryotes for the recognition of ...
3
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985 views

Difference between bacterial chlorophylls

I understand that bacterial chlorophylls are of the form a, b, c and d. But i read in my textbook about pigments like bacterio purpurin and bacterio viridin; are they a part of the 4 types of ...
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How do I compare bacteria growth curves?

I have bacteria growth curves for 5 different temperature conditions and these were created using %red-light transmittance. How do I compare these growth curves? Should I calculate the growth rate and ...
3
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1answer
116 views

If a dead animal is electrified, will it decay?

I was walking past some power lines today, and a flying fox (like a small furry bat, for those who don't know Australian fauna) had grabbed onto two adjacent power lines, completing a circuit, and as ...
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481 views

Resistance to Antiseptics

I know that bacteria can become resistant to antibiotics. Why do antiseptics like alcohols, PVP-I, still work on the strains of bacteria we have today? Shouldn't some bacteria have evolved to be ...
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3answers
466 views

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 ...
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148 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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1answer
244 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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102 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 : http://webcache.googleusercontent.com/search?q=cache:CrtQ9T6K7m8J:www.wzw.tum.de/mbiotec/...
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111 views

What happens to Bacteria at a low pH?

I am conducting an experiment on how different pH levels effect the growth of E.coli. After researching, it is predicted that the most acidic pH level (pH 2) will be most effective at killing (or at ...
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1answer
97 views

How much does sprayed water remove bacteria?

I was quite skeptical about some company claiming that their device was able to suppress 99.99 % of bacteria. Then I read a report testing the germicidal effect of their device, from a large and ...
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1answer
1k views

What is an inclusion forming unit?

What is inclusion forming unit load? I found it when reading this article. What does this measure and what information can be gained form it? Does this represent the amount of bacteria within a ...
3
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1answer
222 views

Lactobacillales vs LAB (Lactic acid bacteria)

As far as I understand bacteria of order Lactobacillales are all LAB (Lactic acid bacteria). So often "Lactobacillales" and "LAB" are used interchangeably. But I also thought that this is not the ...
3
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1answer
722 views

Can different bacteria strains of same species have different genomic sizes?

Can two different strains of a single species have different genomic sizes? I am not asking about plasmid. Can they have different sizes of actual chromosome?
3
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1answer
429 views

What does completing the course of antibiotics accomplish?

This article from the WHO states: If you stop treatment early, there is a risk the antibiotics won’t have killed all the bacteria that made you sick and that it will mutate and become resistant. ...
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1answer
184 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 is,...
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1answer
2k 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 ...
3
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1answer
180 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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125 views

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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1answer
191 views

Is it possible to make anaerobic media too reducing?

I've been struggling to grow an anaerobe (P. gingivalis), I take every precaution to keep the culture conditions free of oxygen, I was wondering if the conditions can be so reducing that they inhibit ...
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2answers
376 views

What culture medium should we use for tap/drinking water bacteria?

We are a group of high school students from Manila who is performing an investigatory project on a topic that we chose which, at first glance, seemed simple, but turned out a bit complicated. We're ...
3
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1answer
53 views

Are bacterial RNA polymerases distributed evenly throughout the cell or localized?

Bacterial cells aren't internally compartmentalized with membranes (like eukaryotes). This naturally leads to an image of a homogeneous interior, but bacterial cytoplasm isn't homogeneous. Case in ...
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1answer
83 views

How to feed bacteria out of lab

I want to take a sample of skin infection bacteria (I suppose combination of staphylococus, strep, etc) and give it to the doctor for analysis but the appointment is in two weeks. The bacteria will be ...
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3answers
161 views

How much genomic variation one usually find within a given bacterial species?

If I find the exact starting position (say 1152471) of the coding sequence of a given gene in the genome of a bacterium, is the genome of the bacterium in general stable enough so that I can expect to ...
3
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1answer
541 views

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 ...