Questions tagged [microbiology]
Microbiology is the study of extremely small organisms. This includes organisms like bacteria, fungi, protozoa, and viruses.
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Does heterogeneous resistance have an impact on the zone diameter observed in disk diffusion susceptibility testing?
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Does the presence of small, discrete colonies within the zone of inhibition, suggesting heterogeneous resistance, impact the zone diameter in disk diffusion susceptibility testing?
"Help ...
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Cynobacteria vs. BGA
I am really confused. On google and other places(though very old) it is mentioned that Cynobacteria are the same as BGA(Blue-Green Algae) and are technically bacteria and are places under the kingdom ...
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Can a stereo microscope be used for mycology?
I have a need for a stereo microscope to do electronics work. I also have a strong desire for a stereo microscope to do mycology. I would like to be able to,
Clearly identify mycelium, from bacterial ...
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Can bacterial DNA solutions, which include other cellular components, be stored without compromising DNA stability?"
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Can bacterial DNA solutions, which include other cellular components, be stored without compromising DNA stability?"
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I'm using the boiling extraction method to extract ...
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What effect does L-cysteine have in a growth medium on Lactobacillus and Bombilactobacillus found in bee species?
To cultivate Lactobacillus and Bombilactobacillus species we used MRS supplemented with 2% fructose in both aerobic and anaerobic conditions and also MRS supplemented with 2% fructose and 0.1% L-...
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How is the zone of inhibition formed in disk diffusion?
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How is the zone of inhibition formed in disk diffusion?
What I mean by the formation of the zone of inhibition is not the ultimate visibility of such zone but the circumstances that result in ...
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Relation of pH and amino acids in microtitr assay
I am testing a Biolog plate (https://www.biolog.com/products/metabolic-characterization-microplates/) in which the wells test for the optimum pH at which my bacterium grows. Aside from having a range ...
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What is the biological pathway for the biodegradation of DDT (pesticide)?
There are various micro organisms which can degrade DDT. Which micro organism is most frequently used for biodegradation of DDT and what is the metabolic pathway by which DDT is degraded?
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What's pooling in the spread plate technique?
"Distributing the organisms by rotating the spreader rather than the plate tends to cause more pooling of the inoculum."
https://asm.org/ASM/media/Protocol-Images/Preparing-Spread-Plates-...
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Qpcr negative efficiency
Hello Stack Exchange Biology world,
I have struggled with my qPRC results for over 5 months. I have a bunch of DNA samples, and I want to find the quantity of Pseudomonas syringae contained. My issue ...
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What is important in the Luria-Latarjet effect?
In the seminal paper
Luria, S.E. and Latarjet, R. (1964) “Ultraviolet irradiation of
bacteriophage during intracellular growth”. Proceedings of the
National Academy of Sciences of the United States ...
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Cell Size and Morphology of Microalgae under Wastewater
Hypothetical situation ahead, I am just curious whether the cell size and cell morphology of microalgae changes when it is under the influence of wastewater. For instance, mixing the microalgae ...
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Why do we choose to use agar instead of agarose in various microbial applications?
When performing gel-electrophoresis we always use agarose. Is there a reason we can't perform it using Agar?
And in microbial culture Agar is commonly used as solidifying agent, could this be replaced ...
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Does inoculum volume affect spread plate outcome?
Background
The spread plate method is a technique used in microbiology to enumerate and isolate bacteria or other microorganisms present in a sample. It involves evenly spreading a liquid sample ...
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What is the genus of this fungus?
I'm struggling to identify this fungus. Is it Aspergillus sp. or Penicillium sp.?
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What distinguishes a colony from multicellular organism?
I would like to inquire what made biologists conclude that colonies such as the famous Volvox is an organism constituted by independent cells as opposed to a multicellular being.
I read that it has ...
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Extremophile hunting and identifying unknown microbes
I'm going extremophile hunting! We're doing a trek by boat between some islands with semi-active volcanic terrain to try to document some interesting species, and running into a problem I've never ...
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Can placing a culture plate upright introduce contaminants from the lid?
Discussion
I have developed a habit of keeping culture plates always inverted, especially those of non-selective media. This precaution is followed after the poured plate is placed inverted in the ...
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Does sunlight interfere with the efficiency of compound light microscope?
I have access to an olympus bx41 microscope. The table on which sits the microscope is in front of a large window and unfortunately no curtains are available. I'm starting to relate that whenever the ...
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Why did a resazurin broth bottle turn pink immediately after being inoculated?
I have lawn cultures of aerobic bacteria kept at (2-8 °C), which I am trying to revive since they were kept longer than recommended. First, I tried to incubate a broth culture inoculated with a ...
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What is the optimal pO2 concentration for automated reactor batch mode EColi expression?
I am wondering what is the optimal pO2 level for an reactor based expression? All protocols I have found indicate for E.Coli pO2 levels just bigger 20%. So, I am wondering what is the optimal level? ...
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Can Gravity convection incubators negatively affect the growth of strict aerobic bacteria?
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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://...
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Can a gene transfer from a plasmid to a bacterial chromosome?
Plasmids are involved in providing resistance to antibiotics. So, can that gene or any other gene transfer from the plasmid to the bacterial chromosome?
Is there any chance where antibiotic resistance ...
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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?
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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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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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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/...
