Questions tagged [microbiology]
Microbiology is the study of extremely small organisms. This includes organisms like bacteria, fungi, protozoa, and viruses.
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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 ...
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Storing bacteria in a dry, room temperature long-term storage whilst maintaining viability
I'm quite new to biology, but I'm wondering if there are any methods of storing bacteria in long-term, dry conditions with no climate control. Perhaps they could be dormant in a powder or granule-like ...
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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 ...
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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 ...
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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. ...
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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 ...
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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 ...
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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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Risk with cultures taken from stagnating water?
Necessary foreword: I'm an amateur and just starting with microscopy and microbiology.
Wanting to observe some protozoa, I collected samples of dirt and water from some pools here in the city and ...
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Which species of iron-reducing bacteria are hyper-sensitive to copper?
I would like to know which species of iron-reducing bacteria are inhibited in their iron metabolism by a copper concentration of less than 500 nano moles per litre.
Searching the internet, I can only ...
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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 ...
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Prevention of disease spreading in animal kingdom
It's my first question on here, so I'm not sure If my question fits the theme. Please refer me to the appropriate one, If I have made a mistake.
So a question that I wanted to ask has to do with ...
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Can I reuse agar in Petri dishes?
Can I simply re-melt agar in a contaminated Petri dish to use it again? I've tried searching for the answer on the Internet, but I was only able to find information about reusing Petri dishes ...
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What is the approx. diameter of a completely "folded up" human DNA molecule, in inches?
The human DNA molecule would be about 6ft if stretched out to a straight line.
I'm curious what the diameter of the DNA molecule normally is when it is "all scrunched up" or "bundled&...
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Concentrating cell concentration after subsampling
I need some help with regards to a concentration correction. I am measuring how many cells detach from a rock vs sonication time. Becuase I start from a rock, I cannot make aliquots and measure ...
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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 ...
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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 ...
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DnaA binding energy to E coli genome
I have been told that DnaA binds strongly to DnaA boxes on the E coli genome, but binds weakly to 8 out of 11 sites near ori. I want to know more quantitatively what strongly and weekly mean. Are ...
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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 ...
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Minimum growing conditions of a given plant
Micro-algae are organisms that can grow in aquatic environments and use light and carbon dioxide (CO2) to create biomass. Researches showed that Micro-algae biomass can be used as bio-fertilizer.
My ...
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Resazurin not turning pink
I want to add resazurin to my media as an anaerobic indicator.
To my understanding, the resazurin is blue when first added to the media, then turns pink after autoclaving, and finally it turns ...
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Unidentified Fish-like Microorganism from pond water
I was looking at my friends pond water and saw several Daphnia. As I was searching, I noticed a Pliomate Rotifer and some other unidentified Microorganism. It looked almost like a micro fish, with a ...
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Are bacteria repelled by self-lysis products?
Intuitively, it seems like treating your own lysis products as chemorepellants would make sense, since getting away from a place where your kind are dying would be a Good Idea, but I can't find any ...
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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 ...
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Why is mold able to survive inside LCD screens?
A week ago i was cleaning and refurbishing an old laptop and i noticed it had spots on the screen. I was able to clean off some of the spots but others were impossible to remove. For a moment i ...
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How much thermal energy is released by the anaerobic fermentation by C. Lungdalii grown on hydrogen
For example, reaction H2+CO2 + X --> acetate + biomass.
How much thermal energy is released kJ/g acetate.
Purpose is to calculate the heat balance of reactor.
Thanks!
Dorian
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Need help identifying this microbe
Sorry for the bad image, we don't have a camera hooked up to our culture room microscope yet. But Has anyone seen these kind of (what I'm assuming are) contaminating bacteria before? We see these from ...
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Conjugation of bacteriophage transduced genes
wonder if it is proven that bacteria can spread genes acquired by transduction or infection with a temperate phage by conjugation or transformation? Can you give me link to article that discuss this ...
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Is there a difference between adult onset and child onset atopic dermatitis and what is the role of the skin microbiome in the condition?
I am a novice in the field of skin microbiology. I am looking to learn about the skin microbiome and its role in atopic dermatitis. As of right now, based on my readings that the biodiversity of ...
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What are these ciliates doing here during cell division?
A while ago I filmed a short (20 min) time-lapse of the cell division of two ciliates. However, I noticed something odd with their behavior. They appear to push against a piece of debris in order to ...
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How to Resuspend cells at cell density of 8 log CFU/ml of bacterial culture whose CFU/ml i don't know at 600nm, also it doesn't grow well on MRS agar?
According to procedure after 24 hr growth of Lactobacillus delbruckii subsp lactis in MRS broth, I have to resuspend it at 10 raise to power 8 CFU/ml and then inoculate it further. But it doesn't grow ...
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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, ...
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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/...
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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 ...
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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 ...
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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 ...
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what is the main difference of immune response between immune deficiency people and normal people?
The only thing I know about the main difference between immune deficiency and normal people is that for immune deficiency people there will be less adaptive immune response.
Let's take the difference ...
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What are these white, fuzzy dome-shaped contaminants growing on my LB agar plate?
We are attempting to extract bacteriophages from environmental samples. We recently had an issue with an unknown contaminant when trying to grow a lawn of M abscessus for a bacteriophage isolation ...
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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 ...
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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 ...
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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 ...
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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 ...
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How to judge the distance of nodes in biological evolution tree
I would like to know the method of judging the distance between two nodes in the phylogenetic tree. For example, in the diagram below, is node 299 closer to node 151, or closer to node 201?
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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 ...
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What are these micrographs of?
There are some images floating around the Internet that were supposedly taken with a microscope, built in the 1920s, that was supposed to achieve resolutions that would normally be ludicrous for an ...
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Does centrifuging and filtering supernatant confer an advantage compared to just filtering?
We are trying to isolate bacteriophages from environmental soil samples. One of the first steps is elution, centrifugation and filtering of the soil samples.
One protocol suggests to:
Elute the soil ...
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How can combusted methane from landfill samples be quantified? [closed]
Background:
For my studies I'm wanting and attempting to make a landfill greenhouse gas emissions (GHG) model that predicts the amount of greenhouse gas equivalent emissions ($GHG_{eq}$ [tonnes/year]) ...
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Is it safe to autoclave waste at the same time as lab equipment?
We have recently moved into a lab space where we share an autoclave with other people.
We generally autoclave empty beakers, flasks, etc., before running experiments, and we autoclave waste (Petri ...
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What is this small creature on the bottom of this leaf?
This first one appears to have been flattened by the slide cover.
This one is not flattened.
Probably like .2/.3 mm in size. All of them seem dead because they are doing nothing. All on the underside ...
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