Microbiology is the study of organisms that are too small to be seen with the naked eye. This includes organisms like bacteria, fungi, protozoa, and others.

learn more… | top users | synonyms

3
votes
5answers
7k views

Why do cell membranes have a lipid bilayer?

Many cells have a cell membrane composed of two layers of lipids, why is it two layers and not just one? What purpose do the membranes serve?
2
votes
1answer
85 views

What are the differences and similarities between fimbriae and adhesins in microbes adherence factor?

Adherence factors in microbes is to attach to a host cell or to an extracellular matrix. So what is the difference and similarities between fimbriae and adhesins?
3
votes
1answer
58 views

Why do some bacteria have an asymmetric replication?

Our teacher said that Bacillus subtilis has an asymmetrical replication fork. I know that this happens only in some strain of the bacteria . She asked us to find an explication for this mechanism , ...
1
vote
1answer
28 views

Why would a bacterial population show initial growth when it is in unfavorable growth conditions?

This figure shows the anaerobe E. faecalis grown in aerobic conditions, E. coli grown in restricted conditions that are not specified. Why do they show an increase in abundance initially? The black ...
0
votes
0answers
18 views

What exactly are polyphenols and what benefits do they provide to humans?

I say somewhere that they are antioxidants, but I was wondering if the two terms are synonymous or if that is just one of many things polyphenols can do.
16
votes
2answers
4k views

Why is 70% ethanol preferred for aseptic techniques?

Are other concentrations (say 80%) less effective,or is this just for convenient manufacturing? Is the concentration chosen only because it is less volatile than 100 percent ethanol and hence safer?
2
votes
2answers
369 views

What does “cellular” mean in this context?

I came across a confusing word when I was reading a Scientific American story, “Controversial Spewed Iron Experiment Succeeds as Carbon Sink” (by David Biello). It goes like this: “One key to the ...
1
vote
0answers
47 views

Which Lactobacillales (Lactic acid bacteria — LAB) strains are capable of degrading starch?

I've been researching bacteria strains but am having trouble finding amylolytic LAB strains with amylolytic and lactic acid producing character. The only species I've found, that are capable of ...
2
votes
2answers
208 views

Why does sulfonamid not inhibit the growth of Rickettsia?

Sulfonamid is an antimicrobial agent, why has it no effect on the growth of Rickettsia?
1
vote
1answer
81 views

Why don't bacteria eat food leftovers?

I have thrown a dirty spoon after eating some pasta into one of my desk drawers (doesn't do me much honor). It stayed there for around a year. My house is warm and I think there is enough humidity for ...
3
votes
1answer
75 views

Plasmid choosing

To design a experiment in feeding of C. elegans. It has to choose a plasmid vector to insert the gene of interest that can feed to C. elegans. Many paper are using pL4440 for the feeding vector, ...
2
votes
3answers
247 views

Does a microwave oven disinfect food?

Imagine I am preparing food, just about to put it into a microwave oven, and some of it falls on the floor. Assuming it got some bacteria or other organisms (viruses?) on it, will the microwave ...
1
vote
0answers
28 views

Symbiosis of Pseudomonas Fluorescens

Have a modest background in molecular biology and presently considering a project that requires some knowledge of botany. Specifically, I seek details on the epiphytic relation between the microbe ...
2
votes
2answers
62 views

Bacteria Replication

I learned this at a lecture, but somehow I have trouble in understanding this. It is said that the bacteria such as E.coli need 20 minutes to divide, but its chromosome require 40 minutes to multiply. ...
8
votes
1answer
2k views

How can Valonia ventricosa cells get so big?

Valonia ventricosa are single celled algae that range between one and few centimeters. In rare cases they can reach sizes exceeding 5cm. They range from grass green, to dark green, and some are even a ...
2
votes
1answer
68 views

How can E. coli affect C. elegans expression?

Plasmids can be transferred to E. coli. These transformed E. coli can be fed to C. elegans to silence its gene expression by RNAi. How can E.coli release RNAi to C. elegans? Even if we assume E. ...
0
votes
0answers
15 views

Counting of surface bacteria in real time

I'm fairly new to microbiology (okay, I'm forced to look into it for a group project). What I'm looking for is a way to quantitatively get an estimate of the number of microbes (bacteria and/or ...
3
votes
2answers
1k views

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.
0
votes
1answer
37 views

Nucleoside analogs that cause mutation

I'm confused with this explanation in my book: 2-aminopurine is incorporated into DNA in place of adenine but can pair with cytosine, so an AT pair becomes a CG pair. This sentence seems odd to me. ...
1
vote
0answers
32 views

Is there a good easy protocol for extracting proteins(enzymes) from fungal mycelium?

I quantify the enzyme (polygalacturanase)activity by DNSA method.To determine endo-polygalacturonase activity I'm searching for a good easy enzyme extracting method.Any suggestions for a suitable ...
4
votes
1answer
658 views

How was the diversity between ethanol fermentation and lactic acid fermentation evolved?

Quite simply, some organisms metabolize glucose under anaerobic conditions via Glucose->(2) Pyruvic Acid->(2)Ethyl Alcohol. Some organisms, however, metabolize to lactic acid. When did such a process ...
2
votes
0answers
30 views

“Antibiotic resistance” equivalent in archaea for selection during cloning

I'm beginning to work with halophilic archaea and I'm trying to figure out a good way to select for cells that have taken up a plasmid. Obviously, one can't use antibiotic resistance since they are ...
1
vote
0answers
30 views

Enrichment of slow growing microbes: Large Test Tubes as an alternative?

Well, i would like to enrich bacterial and archaeal ammonia oxidisers from soil samples using Minimal Salt media. They are slow growing microbes. I would like to enrich them with the aim to produce ...
3
votes
1answer
581 views

Can the RNA in the HIV virus make viral enzymes without entering the nucleus?

If the provirus was not formed yet, can the virus make viral enzymes? (I know that it already has some, but supposing it doesn't)
1
vote
3answers
401 views

Can ampicillin resistant bacteria survive penicillin plate?

in my molecular bio class we were asked a trick question: If the bacteria has a plasmid with that grants it ampicillin ressistance, can the bacteria survive if placed in penicillin? I gave it a ...
2
votes
1answer
24 views

How can I interface cAMP signal or membrane potential from slime mold to an electrode?

I am very much interested in measuring cAMP (cyclic adenosine mono phosphate) signal and membrane potential from amoeba. Since I want to try this as a hobby, what are the basic steps I must do to view ...
8
votes
5answers
3k views

What's the aim of genetically modifying of foods/organisms?

On news, articles etc. experts talking about Genetically Modified Foods and Organisms often mentions about their disadvantages like, their potential to harm human health allergies may become more ...
0
votes
0answers
32 views

Soy kefir that never revitalises in animal milk

If I have kefir grains from goat and I make soy kefir and never revitalise the kefir grains in an animal milk, will that bacteria still be beneficial for the gut? What type of bacteria does it make? ...
9
votes
1answer
108 views

Reasons for the HIV-1 epidemic

So, the HIV-1 jump to humans occurred as early as the 1920s, but the AIDS epidemic didn't start until the early 1980s. Some things I don't understand about this: Why the delay? What is needed for a ...
5
votes
1answer
88 views

How do single-celled predators chase other cells?

From my understanding, single celled organisms have been seen avoiding, and chasing, potential food or other organisms. How do they accomplish this? They do not have eyes or ears or a nervous system. ...
3
votes
1answer
86 views

Ways to fight black mold

Is it possible to introduce a microorganism to a colony of black mold that will kill off the black mold entirely and permanently? Is there a common microorganism that likes to eat them and is harmless ...
6
votes
4answers
1k views

Are all pathogens parasites?

If parasites are organisms that feed on other living organisms, then aren't all pathogens parasites? I've emphasised on 'feed' because I guess the pathogens just eat us (i.e. take nutrients to ...
4
votes
1answer
127 views

How small does a nanobot have to be to “swim through the brain” and access any neuron it wants to?

I read on this question What is in the space between neurons in a brain? that there is actually not much empty space in a brain. But my question is slightly different. Is there a visual demonstration ...
2
votes
0answers
26 views

Can mutation rate be increased for instance by mutagenesis targeting the DNA polymerase?

I am studying a non-cultivable bacterium living in an insect host, and I would like to generate some random mutants of this bacteria while preserving the insect. I am wondering if one way to do so ...
3
votes
0answers
277 views

How much salt [NaCl] is too much in DNA precipitation?

In DNA extractions, how much is too much salt in a CTAB extraction buffer? Protocols hover around 2.5 molar; if you go over this (e.g. 25 molar), will you saturate your solution, and precipitate the ...
4
votes
2answers
77 views

Why lab technicians use indirect (antibody reaction) method for diagnosing?

In microbiology we have two types of microbial diagnosis. The direct method is where we detect the invader's DNA, Antigens or culture to see the exact pathogen while the second, indirect, method is ...
5
votes
2answers
6k views

Why do kefir grains stop growing in soy milk?

Kefir is a fermented milk drink made with kefir grains. It usually is prepared by inoculating cow, goat or sheep milk with kefir grains. I would like to prepare the drink with soy milk, which worked ...
5
votes
1answer
6k views

Why does milk contained in cartons of milk expand?

In the morning, I went to the fridge to drink some chocolate milk. At night, when I took out the same carton of milk, the packaging seems expanded, like some kind of air is inside. Explain please !
3
votes
1answer
66 views

What is the simplest autotrophic cell?

Very simple cells, such as Nanoarchaeum equitans, require a host to provide certain essential ingredients for life. Complex life-forms (like humans) require a whole ...
6
votes
1answer
54 views

Spatial learning in microorganisms

Has there ever been an experiment performed that demonstrated a form of 'spatial memory' in a unicellular organism? I'm imagining something analogous to the classic 'rat in maze' experiments, but ...
4
votes
1answer
87 views

How does botulinum toxin enter the blood stream from the digestive tract?

To my understanding, large polypeptides such as botulinum toxin cannot pass the intestinal lining intact. How, then, can it enter the bloodstream and cause botulism poisoning?
2
votes
0answers
38 views

Why does bacillus thuringiensis produce bt toxin?

Background : B.thuringiensis produces an inactive crystalline toxin during sporulation which when ingested by an insect, gets activated and causes pore formation in gut , subsequently leading to death ...
4
votes
1answer
268 views

What are the most important factors influencing a person’s gut microbes?

You are your bacteria! The probiotics and the antibiotics... There has been on going discussions about how our gut bacteria is important for a healthy lifestyle. Figure 1: Schematic diagram ...
3
votes
1answer
62 views

Cellulose acetate membrane filters vs. glass microfiber filters

At equivalent pore sizes and pressures, which exhibits faster flow rates, cellulose acetate membranes or glass microfiber filters? I know cellulose acetate exhibits low protein binding, but what ...
1
vote
2answers
390 views

Autotrophic and heterotrophic organisms in anaerobic condition

Can both heterotrophic and autotrophic organism survive in anaerobic conditions? If an autotrophic organism does not produce carbon dioxide but requires oxygen, it should not be present in anaerobic ...
32
votes
5answers
4k views

Is there an advantage to antibacterial soap?

There are plenty of different hand soaps out there, as well as hand sanitizers. Is there an advantage to soaps that claim that they're antibacterial vs soaps that just say soap? In particular I'm ...
2
votes
2answers
187 views

Can a fungus become resistant to a chemical such as Potassium Permanganate?

A friend used potassium permanganate solution to treat tinea on the hands/feet but after some initial success, the tinea seems to be making a comeback. Could the fungus develop resistance to potassium ...
6
votes
1answer
54 views

Are there mechanisms that limit the amounts of time conjugation and F-plasmid transfer can happen? If yes, what are they?

Not all bacteria have acquired F-plasmids through conjugation. Some of the mechanisms for this are unsuccesful conjugation events (mechanical disruption), no transfer due to integration in bacterial ...
1
vote
1answer
3k views

Bacterial capsule vs. slime wall

I've read that the bacterial capsule protects the bacterium from phagocytes and prevents water (and nutrients, possibly?) leakage from the bacterium. A less organized and less dense version is called ...
5
votes
5answers
97 views

Can an influenza virus carry other infectors with it?

This idea came to my mind when thinking about how many people become ill in many locations with similar symptoms (fever and rough cough) from Influenza. There are of course different types of ...