Questions tagged [microbiology]

Microbiology is the study of extremely small organisms. This includes organisms like bacteria, fungi, protozoa, and viruses.

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Under a 100x compound microscope, which appears bigger (longer in length) ; a Pseudomonas species or E.coli? [on hold]

Under a 100x compound microscope, which appears bigger (longer in length) ; a Pseudomonas species or E.coli? I'm trying to distinguish between the two under microscope as both appeared to be present ...
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Is there a minimum load below which an infectious agent will not cause disease?

Suppose a single smallpox virus is injected in an human adult's body. Will it cause disease in the host? Is there a minimum microbial load below which it will not cause disease?
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Why we don't have vaccination against all diseases which are caused by microbes?

People can be vaccinated against certain diseases. Principle of vaccination is to use live attenuated load or inactivated. My question is - why we dont have vaccination against all diseases which are ...
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What disease does Saccharopolyspora erythraea cause?

For an examination assignment I have to find a disease caused by the bacterial species Saccharopolyspora erythraea, but I have searched the internet and have found no report of patients being infected ...
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What specific criteria do you use to choose E.coli strain for the experiments? What is the most standard strain?

For my specific case, I would like to know what plasmid to use to express two particular proteins (one of them being the GFP reporter) with its specific promoters. But more important than the answer ...
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E. coli & aspartate

I am familiar with the linkage between aspartate/ligand binding, receptor methylation, and flagellar behavior re. style of locamotion, but I do not know what the bacterium does with the aspartate it ...
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1answer
27 views

Water sample preservation

I am taking my students to collect water samples from different bodies of water. These bodies of water include the local river, a park pond, and water accumulation from recent rain. Once we gather the ...
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Gene introduction in bacteria [closed]

I want to transform the bacteria with my gene of interest inserted inside a particular plasmid. However, transformation is not taking place due to bacterial exonuclease which is degrading the plasmid ...
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1answer
42 views

Growth rate oscillation in the a population of non-interacting bacteria

I have come across this theoretical paper claiming that if you start a batch culture from a single E. coli cell, the exponential growth rate of the population defined as $$k = \frac1N \frac{dN}{dt}$$ ...
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1answer
47 views

Is bacillus strain 2-9-3 really 250 million year old?

I've read that in the last decade (I believe) some scientists discovered a microorganism, which they dubbed bacillus strain 2-9-3, in a crystal of salt that they think is 250 million years old and ...
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Diffussion coefficient of blood

What it the diffusion coefficient of blood in, e.g. water? It is needed for microchannel length calculations I have found a bit different nubmers: 0.94 and 1.66 microns^2/ms, but not sure
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Is there any double staining method to visualise separate colour for plant tissue and fungal tissue?

Is there any double staining method for developing separate colour on fungal tissue and plant tissue when the said 2 types of tissues are intermingled? Unlike my previous question, this question not ...
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1answer
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How DNA probe binds

I am studying about southern hybridization now and I've a doubt.After the DNA has been fragmented using restriction enzymes and obtained on nitrocellulose blot , it is still double stranded (the ...
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How do carbon 13:12 ratios confirm the biological origin of oldest microfossils?

I was reading this article about how Schopf and Valley’s findings in 2017 confirmed that the 3.5 billion–year-old microfossils found in the Apex chert of Western Australia are indeed remnants of ...
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1answer
39 views

Can exposure to blood make pathogens resistant to the immune system?

If a drop of my blood is dropped into a pool of pathogens. Does that act as "reverse-vaccination" for said pathogens? I see this it as a potential risk for bacteria/viruses to compete or get ...
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Species diversity in cheese and yoghurt?

There have been studies on the number of species on humans and in various other environments. I was wondering how many species including: viruses, bacteria, yeasts, and fungi inhabit ordinary farm ...
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What enzyme or bacteria could dissolve plastic?

What enzyme or bacteria could dissolve plastic aside from acetone? Preferably, low-cost and environmentally friendly. Any suggestions would be helpful. I'm targeting for thin plastic (low-density ...
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1answer
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Why is glycerol supplied/used as 87% solution?

While preparing glycerol stocks of my transformed bacterial cells (DH5alpha) the protocol I had to follow was that I would make one 50% glycerol stock (500µl culture, 500µl glycerol 50%) and another ...
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Are olfactive indicators always the result of inadequacy in sanitation?

Question If you can smell the scent of food in a thoroughly cleaned container, does that imply trace amounts of food particles remain? Scope It goes without saying that our sense of smell is ...
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1answer
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Is it unusual for populations of archaea to be found living inside trees?

The NPR News article and podcast Getting Fire From A Tree Without Burning The Wood begins with A scientist walks up to a cottonwood tree, sticks a hollow tube in the middle and then takes a lighter ...
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How protozoa spawns in newly formed ponds?

How big protozoa like Paramecium caudatum, Amoeba proteus, Euglena viridis etc. appear in newly created ponds of water? Suppose there was rain, and pond was formed. Or earth, dead leaves, live leaves ...
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1answer
68 views

Can a pathogen be totally resistant to the human immune system?

Can a pathogenic organism be totally resistant to the human immune system? For the purpose of this question, the organism in question must cause a disease. Examples of organisms that would qualify as ...
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1answer
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Salt Bridge for Microbial Fuel Cell: Full or Partly Full?

I'm making a microbial fuel cell out of benthic mud and salt water in containers. My salt bridge will be made of agar and table salt solidified in PVC pipes. Does the salt bridge connecting the anode (...
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What strain of Arthrospira (Spirulina) is this?

Can anyone help me to identify this strain of Arthrospira (Spirulina)
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Methods to degrade Bacillus thuringiensis cell wall

I'm looking for cell lysis methods for Bacillus thuringiensis in order to extract a protein. I considered using enzymes to degrade the cell wall, but itt seems that some well-known wall-degrading ...
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Found this moving inside S. cerevisiae, can someone tell me what is this?

This is my first post here. I found this in a microbiology practice and my teacher had no idea. S. cerevisiae dyed with methylene blue. Is the one in the middle; you can see a small thing moving ...
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1answer
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How could pharmaceutical metabolizing bacteria be used to synthesize them?

Lets say I have a pharmaceutical "P". It can be broken down by enzymes of one strain of bacteria into two molecules one of which can be further metabolized enzymatically by a different strain of ...
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what are best methods for mrsa screening in hospital?

methods for screening MRSA are based on PCR (mecA detection) and MRSA latex test and culture. I need to know sensitive, specific and cost-effective methods for diagnosis MRSA infection on one work day ...
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Can you increase the microbiota in an insect?

I know you can suppress the microbiota of an insect with antibiotics, but I´m am looking for a way to increase it. For example, can I feed an insect with something that helps boost the bacteria like ...
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How do I homogenise a small pellet of 10 to 50 cells within less than 50 µL?

I have a problem with declumping/ homogenising bacterial cells in small volumes (10 to 50 µL). I know that I can get all of my cells out of the tube, but they are still stuck together and won't form ...
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Pits, symplastic or apoplastic pathway?

After water has moved through the endodermis through the Casparian Strip, water continues to move down the water potential gradient into the xylem vessels through the pits, is movement through the ...
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DNA replication in $ E.coli $

$ E.coli $ has circular DNA which I guess implies one strand forms the outer circle and the other the inner one. So, is there a way to know if the replicated DNA forms the outer or inner circle? In ...
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Virulence Factors of Francisella tularensis

After completing research on the virulence factors of Francisella tularensis, I was wondering about a few specific structures/toxin and whether these are virulence factors of Francisella tularensis or ...
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Why do bulls-eye rashes look like they do?

People infected with Lyme Disease often present with an erythema migrans ("migrating redness") rash. Most often, these rashes are in the shape of a bulls-eye. Rash image. Presumably, this is a ...
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How is Pseudomonas aeruginosa diagnosed?

I know that P. aeruginosa is cultured on an agar plate, but which media or assays make it distinct from other Gram-negative bacteria?
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Could a strong magnet field repel the body before damaging it?

Could a magnetic field be strong enough to damage the body or erase the brain? Blood is slightly diamagnetic, so if the field was strong enough, could it repel a body evenly? Could a diamagnetic ...
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Is an uninoculated control (slant) catalase positive or negative?

The catalase test is a laboratory test utilized in identifying organisms which produce the enzyme catalase. Is an uninoculated control (slant test only) catalase positive or negative? I am assuming ...
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What concentration of hydrogen peroxide kills mold?

There are numerous articles online which claim that household 3% hydrogen peroxide can kill mold growing on household surfaces, yet I haven't managed to find scientific studies that show that. My ...
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fimbriae under AFM

Can any one,please, recommend a protocol for watching bacteria with fimbriae under atomic force microscope? I have tried a lot but always there were no fimbriae i don't know why.
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In my DNA sequence for one sampling site there're W's; Y's; R's and K's?

I also just experienced the same thing with my DNA sequences, there are w's, Y', R', s' and k'. This is the very first time I've seen this. I am used to N but not these ones. Please kindly assist with ...
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when you are to non-culturally detect the presence of E. coli in the soil from a cow pasture?

You are to non-culturally detect the presence of E. coli in the soil from a cow pasture. You do this by extracting the total DNA from a sample of the soil and PCR amplifying with E. coli-specific ...
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Is there a consensus on the best Machine Learning model for Antimicrobial Resistance (AMR) prediction?

Prediction of bacterial resistance/susceptibility to antimicrobials (from genotypic data) using Machine Learning methods is a problem that has started receiving interest in recent years. The ...
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Operon Repressors and activators

I know that the repressor when it binds to inducer it cannot bind to the operator and transcription goes on. As for the activator, it is made either active or inactive based on the environment and ...
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1answer
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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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1answer
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Is it possible to identify this microscopic particle?

So I was playing amateur scientist with my 11 year old. This photograph is from rainwater in a bird-feeding bowl in south England, at 300x. It looks biological, but I have no idea what this is. Is ...
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1answer
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What do the text annotations in an electron micrograph mean?

I saw a photograph taken from an electron microscope, with some text. I want to know what is the meaning of these numbers and letters? Thank you! Regards.
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synthesis of zn nanoparticle

Sir the protocol I followed where it has been written... 1st using lactobacillus in Mrs media (50 ml in 250 ml conical)..we allowed to incubate for 24 hrs then added 0.1M znSO4 (50ml) and 0.4 M NaOH(...
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What makes an E.coli an E.coli, genotype or phenotype?

According to this paper, among 61 strains of E. coli they studied only 6% of the genes are common in all. Which means that the overwhelming majority of the genes are not shared. And wikipedia ...
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Why doesn't alum coagulate my cyanobacteria?

My collected rainwater has a pronounced blue-green tint which I believe to be due to the presence of cyanobacteria. I have been trying to remove the cyanobacteria using aluminium sulphate, but it ...
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Why are tardigrades so rare?

If tardigrades are so resilient and nearly immortal, why are they so rare when looking at samples of a pond or lake, where tardigrades should thrive? I've met people who've been studying protozoa and ...