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Questions tagged [microbiology]

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

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992 questions
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Non-harmful bacterial invasion of cells

There are bacteria that can enter body cells as parasites. Could it be that some of these are benign, such that the guest will not kill the host cell it lives in (especially in human)?
Robertos
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Why does chlorination still work?

Chlorination has been used for over a century to disinfect water supplies. Why haven't microorganisms evolved immunity to this chlorine by now?
Gordon Stanger
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Sugar as a defence against bacteria?

An answer on another SE site mentions that sugar "at a certain level acts as a preservative". I've always been taught that microorganisms eat sugar and expel acids, that is why sugary food are damaging to teeth. How is it that sugar acts as a…
dotancohen
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How do chemists calculate the existence of billions of organisms?

So the packaging of Bio-Cultures Complex says that it contains a minimum of a billion viable organisms per capsule. How has such an estimate been drawn? Have they counted a smaller amount and then multiplied it?
mavavilj
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Is it plausible that eukaryotic organelles like flagella and cilia are the result of endosymbiosis with spirochetes?

This was a claim by Lynn Margulis explained over at this link. The sense organs of vertebrates have modified cilia: The rods and cone cells of the eye have cilia, and the balance organ in the inner ear is lined with sensory cilia. You tilt your…
InquilineKea
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What is the difference between a spore and a cyst?

Last year I read a course in biology. During that course I learnt that Protozoa like Lamblia intestinalis or Entamoeba hystolitica form cysts in unfavourable conditions. This year I read a course in microbiology. I learnt that bacteria like…
Teiko Abe
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If silver nanoparticles kill bacteria by penetrating the cell membrane, why don't they also kill human cells on contact?

Apparently, the silver from the nanoparticles can penetrate the cell wall of bacteria and kill them from the inside. Why, then, doesn't the same happen to human cells, e.g. the skin on my foot when I wear nanosilver-coated antibacterial socks, or…
vashekcz
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Are all known germs benign in small enough quantities? i.e. Why do we wash our hands?

We know that we wash our hands because germs can get into our body through the nose, the mouth, the eyes, cuts, etc. But I doubt we can completely clean our hands of germs every time we wash them, down to the individual bacterium or virion, even if…
Kal
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What types of archaea have been found in animals?

I am curious as to the species or "types" of archaea that have been found to reside within animals symbiotically. One of the only ones I can think of off the top of my head are methanogens, which live in the gut of ruminants for example.
LanceLafontaine
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Are there any bacteria, in our environment, able to break down nitrate under aerobic conditions?

Given a fix volume of water saturated with dissolved oxygen through aeration. Suppose that ammonium, Nitrosomonas, and Nitrobacter are always available in the water. We know that some of the ammonium will eventually be oxidized, by the bacteria, to…
user11750
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How do retroviruses exit the cell

Do they just pass through the membrane? Is there some specific transporter or mechanism? Does it vary? I've seen pictures if retroviruses outside the cell but no details
D J Sims
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Does sunlight kill rotavirus?

Does sunlight Kill Rotavirus? Maybe freezing? Norwalk or similar. Its a practical question for bedding.
Btuce Johnson
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Why are viruses considered microbes?

My question is simple. Why is a virus considered a microbe? Considering a microbe is considered to be a "living" unit of life, which viruses are not.
Surfboy123
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Re-solidify disturbed agar plates

I am stuck in trouble while pouring LB agar onto my petri dishes. I had to add kanamycin to my plates just before it started to solidify, out of forgetfulness, which I tried to mix using the tip. The plate was such a disaster! Is there a way to melt…
piscean_1993
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Need for proper air filter for bioreactor?

I am going to build a simple bioreactor for microalgae growth. I already have fluid filters pore size: 0.2um, diameter: 25mm https://nl.vwr.com/app/catalog/Product?article_number=514-4039 I wonder if I can use them for air filtration to avoid the…
Narj
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