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

5
votes
2answers
473 views

Sparking during electroporation of plasmid DNA into bacterial cells

During electroporation of bacterial cells (I work with Mycobacterium tuberculosis, but I think this applies to E. coli as well), sometimes I get sparking. I've read this is due to salts present, ...
4
votes
3answers
2k views

Why do yeast ferment Equal sweetener

I had my students conduct a fermentation experiment manipulating sugar amounts (number of sugar packets in solution) and measuring CO₂ production via capture in a balloon and measuring circumference ...
4
votes
3answers
155 views

What is the mechanism of oxygen uptake in E. coli?

How does E. coli uptake oxygen? Most of the literature I found is concerned with response to oxygen level supplied in the medium, as opposed to how much is actually transported inside. Can they shut ...
4
votes
2answers
137 views

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, ...
4
votes
3answers
48 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 ...
4
votes
2answers
356 views

Do all Gram negative bacteria cause septic shock?

Do all Gram negative bacteria cause septic shock? If they don't could they if you attacked them with an antibiotic that could lyse the cell? For example any antibiotic that attacks the cell wall, ...
4
votes
2answers
257 views

How many different protein coding genes are in the Human Biome?

There are approximately 20k protein-coding genes found in the human genome. This number is presumably very small when considering all the genomes found in the diverse microbes associated with the ...
4
votes
1answer
390 views

What do you call a virus when it's cured?

When a cure has been found for a virus, can it be called such anymore? Virus implies it's something you've contracted that you just have to live with until (hopefully) your body can overwhelm and ...
4
votes
1answer
32 views

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 ...
4
votes
1answer
82 views

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 ...
4
votes
2answers
440 views

Does making yogurt from non-pasteurized milk work against possible disease bacteria?

In the past, when there was no pasteurization, could making yogurt from milk lower the chance of getting infected by bovine tuberculosis (or other diseases from infected milk)? For example, would ...
4
votes
1answer
115 views

DpnI over-digestion

We have a long protocol that we are optimizing that includes DpnI digestion of a PCR product (to remove any of the template DNA if it's methylated, and while we're not certain in the blind tests, ...
4
votes
1answer
33 views

Is the regulation of lactose operon different between Gram + and Gram -?

I know that in E. coli the lactose operon is shut down by CAP protein when binding cAMP. Is this true also for Gram positive bacteria?
4
votes
1answer
303 views

How do I measure bacterial growth in agar dishes (either by cell mass or by cell count)?

I am doing an experiment in which I am growing S. mutans in agar dishes, and I am not sure how I would measure the growth of the S. mutans. I am also not sure if I would do this by measuring cell mass ...
4
votes
1answer
74 views

Are all functions of a human cell known? [closed]

Please bear with me as I'm intruding into your world from a computer science background. In programming, once you have created a program, you know all functions of that program. Thus, 100% knowledge ...
4
votes
1answer
57 views

Why is the ebola virus so intense now?

So i'm looking into the ebola crisis and it seems the death toll is really getting crazy. I understand that it's a cytomegalovirus and that it basically overwhelms the immune system due to it's size ...
4
votes
1answer
42 views

Is there any way the food industry can benefit from biofilms?

I realize all of the disadvantages, but I am wondering if the food industry can actually benefit from the formation of biofilms.
4
votes
1answer
98 views

Beetroot white skin mould

Does a mould make a beetroot poisonous or inedible ? Lemon's mould for instance, makes penicillin, but it's green there, and I'm allergic to penicillin, would the white mould produce penicillin too? ...
4
votes
2answers
164 views

Is every part of a virus important for replication?

Is every component of a virus absolutely essential for its infection and replication in a host cell? Or can you just have parts of it to cause infection?
4
votes
1answer
139 views

Non-monotonic knock-out effects in prokaryotes

Typically, when performing gene-knockout, the experimenters select one gene to remove/replace-with-junk and then see if the prokaryote can still undergo fission. If it continues to reproduce then the ...
4
votes
1answer
87 views

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 ...
4
votes
2answers
68 views

How can fresh cavities form at the margins of sliver amalgam fillings on teeth?

Silver amalgam fillings predominantly contain silver a known bactericidal agent and mercury which a known toxin and has bactericidal property. So how is it that the plaque bacteria survive near the ...
4
votes
1answer
157 views

Vigorous shaking for HFR interrupted mating

I am trying to reproduce E. coli interrupted mating using an HFR strain, and I read that the cultures should be vigorously shaken at times to interrupt the DNA transfer from the F+(HFR) donors to the ...
4
votes
0answers
87 views

What is this fuzzy, black fungus that grew on my plates in the 4⁰C room?

I often find the fungus below growing on my (ostensibly) sterile plates in the 4⁰C room. Presumably it takes a few days to reach this size. The colony looks puffy and dimpled in the middle, like a ...
4
votes
1answer
81 views

Identify the pink mold infecting refrigerated lemons [closed]

I made lemon juice 6 month ago. I just washed the lemon using brush and then cut them into pieces. Then I put one layer of lemon in the bottle followed by one layer of sugar Again one layer of lemon ...
3
votes
2answers
2k 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 ...
3
votes
2answers
35 views

DNA polymerase I exonuclease activity

Does DNA polymerase I in bacteria use forward or reverse exonuclease activity to remove RNA primers? One of my books says it uses 5' to 3', but another says it uses 3' to 5' exonuclease activity. ...
3
votes
1answer
38 views

Can a plate with incompletely filled LB agar be used?

I am falling short of LB agar plates and I have a plate with less LB agar poured. I meant, the plate is not fully filled with the agar (it was the last plate I poured the medium into). Some part of ...
3
votes
1answer
79 views

Consumption of NAD+ in glycolysis

Out of 10 steps in glycolysis, only one reaction- Glyceraldehyde 3-phosphate (G3P) to 1,3-bisphosphoglycerate (PGP), uses NAD+ and thereby producing NADH. Furthermore, this very step is solely ...
3
votes
3answers
100 views

Why do 6-8% of diphtheria patients do not develop natural immunity after being affected?

I am thinking of why some patients do not have natural immunity after exposure to the A-B toxin of diphthria. I think the A-B exotoxin is the key factor causing this disease and should trigger memory ...
3
votes
1answer
91 views

Is there a difference between drinking water straight from the tap compared to leaving it to sit?

An idle question - if a glass if filled from the tap and consumed immediately, it contains some dissolved oxygen from the physical process of moving through the pipes & tap. If left out ...
3
votes
1answer
57 views

Can we attack viruses by attaching proteins and such to their shells?

Haven't looked into this to very long, but an initial search didn't return anything. HIV uses certain co-receptors to enter our cells. Could we flood the blood stream with specially designed ...
3
votes
1answer
92 views

What is “bacto” peptone?

Standard recipes for yeast medium often include "bacto-peptone". Is this the same as bacteriological peptone? Is there an authoritative source that spells it out?
3
votes
1answer
80 views

When might an inhibitor of bacterial transformation be useful?

I am part of a project elucidating some structures that are required for bacterial transformation. We have the opportunity to screen inhibitors of the system to stop it from functioning. I am not a ...
3
votes
2answers
241 views

Factor causing Methicilin-resistance in MRSA?

I think the main reason is the natural selection that is causing methicillin-resistance. However, I am not completely sure what this means practically. Here, the original question: MRSA was isolated ...
3
votes
1answer
963 views

Is it possible for a person to become “reinfected” with the same strain of a virus?

If a person contracts a virus, viral conjunctivitis for example, is it possible for the individual to become "reinfected" with the exact same strain of the virus once the person has it treated and the ...
3
votes
1answer
163 views

What molecular processes are involved in pseudopodial extension?

I am curious as to the processes and mechanisms involved in the extension of pseudopodia in amoeba. How does the cell know and control the direction and extent of pseudopodia formation at a molecular ...
3
votes
1answer
676 views

“Acellular” designation for organisms

Why do some biologists refer to single-celled organisms such as Amoeba and Paramecium as acellular (i.e., without cells) rather than unicellular (i.e., one cell)?
3
votes
1answer
55 views

Did the Britons 100 years ago have different intestinal flora and fauna?

Note: this is not a question about history, but about human digestive system over time :) I know a lot of colleagues who traveled for business trips to India. All of them caught terrible diarrhea ...
3
votes
1answer
74 views

Organisms in food deposits

I have just discovered that my kitchen sink pipe has been leaking for quite some time (possibly months) which has resulted in water and food deposits collecting in my cupboard. I smeared some of the ...
3
votes
1answer
93 views

How does sucrose protect bacterial cells in lysozyme solutions?

I have a microbiology question. When we put bacterial cells in sucrose solution with concentration higher than 0.5M we observe plasmolysis - the cytoplasmic membrane detaches from the cell wall due ...
3
votes
1answer
148 views

By what mechanism is Streptococcus bovis acting as a risk factor for colorectal cancer?

Streptococcus bovis bacteremia/endocarditis is considered a risk factor for colorectal cancer. What pathophysiological mechanism may link the two together?
3
votes
1answer
449 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 ...
3
votes
1answer
190 views

For people who work in microbiology labs, what software do you use to manage your strains?

It's just a small microbiology lab that currently records everything on paper, and there's quite few mutants as well. Is Excel commonly used for this sort of thing? Or is there a better software to ...
3
votes
2answers
110 views

Highly spherical Radiolaria; does this image accurately depict the organism?

If I understand correctly, Cenosphaera spp. is a type of Radiolaria, which is a type of zooplankton. The following is an image of Cenosphaera spp. is from the supplementary material (Figure S2) of ...
3
votes
1answer
313 views

Can Naegleria fowleri enter through the eyes ( example rinsing/splashing eyes with water)

I understand that it primarily enters the body through the nose by by "feeding on the olfactory neurons in the nose" as answered here in a different question. Would the nerve cells in the eyes present ...
3
votes
2answers
227 views

Short-term Lamarckism in asexual single cell organisms

I was reading through the Karr et al. (2012) whole-cell computational model. One of the things they did was to induce single-gene disruptions in their model. They observed several to be fatal, but: ...
3
votes
0answers
36 views

How often does bacterial transformation happen?

I have been reading: M. Dröge, A. Pühler, W. Selbitschka, "Horizontal gene transfer among bacteria in terrestrial and aquatic habitats as assessed by microcosm and field studies", Biol. Fertil. ...
3
votes
0answers
35 views

How many eukaryotes are there on Earth?

I have been reading: William B. Whitman, David C. Coleman, and William J. Wiebe, "Prokaryotes: The unseen majority", Proc. Natl. Acad. Sci. USA 95, pp. 6578–6583, June 1998. [Full Text] [PDF] ...
3
votes
0answers
167 views

Can someone explain the color-changing unit (CCU) to me?

I've been physically carrying out serial tenfold dilutions on samples of Ureaplasma to work out the color-changing units (CCU). As a definition, the CCU is the highest dilution at which there is a ...