Questions tagged [bacteriology]

A subdivision of microbiology dedicated to the study of bacteria.

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Can Gravity convection incubators negatively affect the growth of strict aerobic bacteria?

Background Gravity incubators rely on natural convection for heat distribution. There is no fan or blower system, and the heat rises from the heating element at the bottom of the incubator. https://...
Freezing Soul's user avatar
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Can a gene transfer from plasmid to bacterial chromosome?

Plasmid is involved in providing resistance to antibiotics. So, can that gene or any other gene transfer from plasmid to bacterial chromosome? Is there any chance where antibiotic resistance is ...
Amit Kumar's user avatar
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How can Clostridium tetani proliferate in relatively minor wounds?

It is often reported (NIH) that some of the most common infections by Clostridium tetani are in minor wounds where, in theory, blood (hence oxygen) supply should not be completely disrupted. How can ...
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Storage of bacteria in MgCl2 at 4 degrees

I have a small question to which I am unable to find a proper answer. Will bacteria in a MgCl2 buffer (or similar solution) at +4 degrees Celsius survive storage for 1-2 days? Or will they die? What ...
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How can one store non-sterile culture media in dissolved form in the refrigerator?

How do I store non-sterile culture media in dissolved form in the fridge in a clean but non-sterile container? The powder of the media (Broth, Nutrient agar, MAC, or MH agar) will be put in a glass ...
Freezing Soul's user avatar
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How do i create sustainable readily available stock cultures to act as Gram stain controls?

My investigation on the matter Ref #1 Staining known Gram-positive and Gram-negative organisms on either side of your unknown organism act as positive controls for your technique. (Microbiology ...
Freezing Soul's user avatar
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Can a non-pure culture be used for reliable rapid phenotypic diagnostic tests?

Can a non-pure culture be used for reliable rapid phenotypic diagnostic tests (e.g. catalase, oxidase & gram stain)? "Slide Test Method Obtain a pure culture of the organism to be tested. ...
Freezing Soul's user avatar
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Ames Assay Confusion: Aren't the odds of spontaneous revertants too low to be able to accurately test the mutagenicity of certain compounds?

I am a student conducting a test with the Ames Assay. This assay uses a strain of bacteria that has a mutation in an amino acid synthesizing operon, which doesn't allow it to synthesize its protein. ...
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Why are my bacterial smears disappearing?

I'm trying to inspect simple stained bacterial smears. But my smear suddenly disappears after a successful inspection with the oil immersion lenses. The background can become too red (the color of the ...
Freezing Soul's user avatar
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What could be the cause of strange brown discoloration around some bacterial strains' colonies on macconkey agar?

Acinetobacter Unknown (Yellow TSI, Oxidase negative, Catalase positive) Unseeded plate My only guess is that the initial pH of the poured agar is too acidic (too red), so any alkalinity is more ...
Freezing Soul's user avatar
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How do microbiologists decide whether two morphotypes on the same plate belong to the same strain?

Background Colony: A colony, in microbiology, is a visible cluster or mass of microorganisms (such as bacteria or fungi) that has grown and multiplied on a solid agar medium. Each colony represents a ...
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Is there a reliable method to determine if heat fixation was inadequate before proceeding with further staining steps?

Background Heat Fixation: Heat fixation is a technique used in bacteriology and other biological sciences to affix bacterial cells or other microorganisms to a microscope slide. This is achieved by ...
Freezing Soul's user avatar
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Carbon dioxide concentration in alkaline media

I am running a batch experiment using penicillin bottles where I have bacteria growing for 21 days in a highly alkaline media (pH 10). I am measuring the CO2 and O2 content in the headspace over time, ...
Franco Grosso's user avatar
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Does cooking kill all bacteria?

So I know that the general rules is that pathogen prone foods such as chicken shouldn't be consumed after 2 hours at room temperature. Cooking meat such as chicken is necesary as it kills the ...
Ethan's user avatar
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How do the qualitative tests for E.Coli work, which chemicals are used?

There are test kits that to detect E. Coli in water, by mixing a small sample of water with a certain chemical. After a certain time, the sample changes color depending on the presence of E. Voli ...
mart's user avatar
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How can one use motility testing as a practically reliable test for organisms identification in bacteriology?

Background information: The motility test is used to determine whether an organism is motile or non-motile. There are three types of bacterial motility *: Active movement: true motility that we are ...
Freezing Soul's user avatar
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Can single-Use Gloves carry bacteria on their outer surface?

In bacteriology, can I touch items (e.g. oxidase discs) with my gloves not fearing to contaminate these items? Are these gloves (e.g. Disposable nitrile gloves) made so that bacteria can't adhere to ...
Freezing Soul's user avatar
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What's the grade of D-glucose that can be used in glucose assimilation test in bacteriology?

Background information Carbon assimilation test is based on the ability of a bacterial species to utilize an organic compound (e.g. D-glucose) as a sole carbon source. This means that for carbon ...
Freezing Soul's user avatar
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Can I have LAMP on the bench / in the field?

I am interested in LAMP for detecting small amounts of DNA (loop-mediated isothermal amplification and yes, I know the initials don't match). I am trying to figure out exactly how clean/(sterile?) ...
Laura's user avatar
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What is the mechanism behind antibiotic resistance and how can it be mitigated or prevented? [closed]

What causes antibiotic resistance, and how can we combat it? I am interested in the mechanisms behind antibiotic resistance and strategies to prevent it in bacteria.
nane albert's user avatar
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A DNA extraction protocol that is equipment-less for bacterial metagenomes?

I am going into the field soon to sample a very remote environment. For reasons that are unimportant here, I would like to extract bacterial DNA from these samples in the field. I will have access to ...
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Can you perform D-glucose assimilation test for a bacterial strain without API kit?

Background facts: Glucose assimilation test is based on the ability of a bacterial species to utilize glucose as a sole carbon source. The test is designed to determine whether the organism can use ...
Freezing Soul's user avatar
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1 answer
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Why do bacteria in a urinary tract infection (UTI) cause bleeding?

It seems that when a urinary tract infection happens, bacteria will cause inflammation to the lining of the urinary tract, and this will cause bleeding. What is the exact process for the inflammation ...
flen's user avatar
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Endospores contact with surfaces

I am currently studying endospores-forming bacteria. To be specific B.subtilis. I noticed that the formed spores have strong contact "grip" with the surface it is forming on. For example, ...
Anwar Elhadad's user avatar
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Why isn't bacterial colony a monolayer?

I am an engineer entering the field of microbiology. I was watching bacterial colonies (lab strain E. coli to be specific) being grown on agar plates. I was surprised that the bacterial colony was not ...
Deep's user avatar
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How can a layperson get their hands on a specific strain that's not readily available commercially?

I'm mostly interested to get my hands on L.plantarum D-103, but there are a few other strains as well. D-103 is e.g. mentioned here https://meridian.allenpress.com/jfp/article/80/10/1682/199965/...
Anton Rodenhauser's user avatar
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How to figure out growth/culture conditions for a specific strain?

Specifically, I'd like to find out how to grow ME-3 L.Fermentum (DSM 14241) at home without any fancy equipment. What food does it need? Sugar? Lactose? Something else? At what temperature does it ...
Anton Rodenhauser's user avatar
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Methods of denaturing BL21 E.coli other than using lysis buffer and sonication

The goal is to try different denaturing methods for BL21 E.coli. However, finding detailed paper on this is challenging as most articles do not seem to include the details of their denaturing ...
Pumla 's user avatar
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Superbugs in eusocial animals

I am not a biologist, and I'm interested in eusocial animals, and the porous habitats in which they live. I know few facts about diseases in these animals: I know some interesting instances of viruses,...
user71674's user avatar
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What is the easiest way to determine the species of non-tuberculous mycobacteria?

We have isolated a mycobacterium strain from patient sputum using an NTM Elite plate. When inoculated into an MGIT tube, we observe fluorescence when observed under UV light, which means it is highly ...
Johan Wikström's user avatar
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What's the purpose of using more than one culture medium for bacterial isolation?

What's the purpose of using more than culture medium for bacterial isolation? Why not use just one? If this is not generally used in isolation of various types of bacteria, I'm concerned especially ...
Freezing Soul's user avatar
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How are spacer sequences created in a prokaryotic genome?

The CRISPR/Cas defense mechanism uses spacer sequences between palindromic repeats to search for the sequence to cut by an endonuclease. But how are these spacers created? Let's take Bacteriophages, ...
Void's user avatar
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7 votes
1 answer
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Has there been evidence that there has been coevolution in E. Coli strains with the T4 bacteriophage?

According to Evolution of T4-related phages, there have been multiple instances of evolution in the T4 coliphages. Per the article, there are many T-even phages that have insertions from other ...
spaik's user avatar
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4 votes
1 answer
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Doesn't pasteurization kill gut bacteria such as Akkermansia muciniphila?

I've recently watched two presentations on YouTube (this and this) about Akkermansia municiphila, a commensal bacteria that feeds on the mucus of the gut. What I find confusing is their claim about ...
Paul Razvan Berg's user avatar
1 vote
1 answer
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Naming the Rings of Flagellar Structure

I will apologise ahead of my very basic question. I just read about Flagella Structure and learned that there are 4 rings, namely "L Ring", "P Ring", "MS Ring", "C ...
green onion's user avatar
5 votes
1 answer
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Why does adding calcium chloride aid in bacteriophage infection?

We are attempting to isolate bacteriophages from environmental soil samples and most protocols recommend adding CaCl2 to the media to aid bacteriophage infection, even though they all recommend ...
Johan Wikström's user avatar
4 votes
1 answer
115 views

Why would it be impossible for gram-positive bacteria to store sulfur as gram-negative sulfur-oxidizing chemolithotrophs can?

I have a question that I am not sure what is the correct answer on <<Brock's Biology of Microorganisms>> When the book introduces "Cell Inclusions", there was a mini-quiz that ...
green onion's user avatar
1 vote
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What prevents the diffusion of proton gradient in Gram (+) bacteria [duplicate]

The proton gradient in bacteria is important to power FTPase and flagella. How do Gram (+) bacteria maintain a proton gradient without a periplasm (Gram (-)) or intermembrane space (mitochondria). Why ...
Curious Student's user avatar
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How does the cell-wall ultrastructure of gram negative bacteria justify it being unable to Sporulate?

The following is a quote from my Microbiology Lecture PPT: "Some gram positive bacteria but NEVER gram negative ones produce spores under harsh conditions". It got me wondering why gram ...
Doe Pual's user avatar
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Is there a way to relate the OD to cells/mL without doing a standard growth curve?

I am helping out with an experiment with multiple bacterial cultures (>20 species). I need to a very specific concentration (cells/mL or CFUs*/mL) for this purpose. Unfortunately it appears that ...
Dunois's user avatar
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Understanding the names of microorganisms of the normal body flora

I'm taking an introductory course to microbiology and immunology, and i have been required to memorise the following microorganisms of the normal flora. I'm trying to understand before I memorise, and ...
Doe Pual's user avatar
1 vote
1 answer
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What are the W and DSM codes for the following bacteria referring to?

In this paper the following bacteria are listed: Bifidobacterium bifidum W23 (DSM 26331) Lactobacillus salivarius W24 (DSM 26403) Lactobacillus acidophilus W37 (DSM 26412) Lactobacillus casei W56 (...
Rob Simpson's user avatar
1 vote
2 answers
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Methods to obtain the mass distribution of an ensemble of bacteria?

Are there any mainstream methods to obtain the mass distribution of a bacterial population? What kind of assumptions to they make? Could anyone point me to some references?
Gyromagnetic's user avatar
2 votes
1 answer
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Where in the biological realm is vitamin B5 chiefly produced?

Can yeast produce pantothenic acid (vitamin B5)? Do bacteria efficiently produce it? Or does it only come from plants? The Wikipedia page for pantothenic acid doesn’t seem to answer the question (...
Hans's user avatar
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How would you measure the diameter/radius of a non-circular bacterial zone of inhibition?

Typically when we're testing the antimicrobial effects of some substance on bacteria growing on an agar plate, we get the area or diameter/radius of the zone of inhibition. But what do we do in cases ...
Zuhair Qureshi's user avatar
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1 answer
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Beneficial effects of the fungi of a termite mound on the diseases suffered by the termites

My motivation to join this Biology Stack Exchange is the article by David Pride that I've read from the Spanish edition of Scientific American, that's Investigación y Ciencia. The article is [1], and ...
user71674's user avatar
2 votes
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Setup of terrarium for an early life experiment

I'm building a terrarium in which an early life environment will be simulated. Over multiple years a few experiments with different starting molecules/atoms will be held in it. The selected materials ...
FoundABoxOnTheSideOfTheStreet's user avatar
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What nutrients are necessary for Bacillus subtilis germination?

What are the necessary conditions to germinate Bacillus subtilis spores? Under laboratory conditions, spores of B. subtilis are often heat-activated for 30 min at 70°C to increase their germination ...
Anwer Ak's user avatar
-2 votes
1 answer
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Does centrifuging the bacteria culture removes bacteria leftovers?

Usually, we centrifuge bacteria culture to either replace the media, control its density (OD), ..etc. I know that when centrifuging the cells are pushed to the bottom while the media (solution) ...
Anwer Ak's user avatar
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1 answer
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Is bacterial respiration a continuous process?

Respiration in micro-organisms is the process of releasing energy from food. There are two ways of doing so: Aerobic respiration occurs in the presence of oxygen and produces ATP from the complete ...
Anwer Ak's user avatar

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