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.

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Is there a practical upper limit to amount of nucleotides or genes in a transformed plasmid?

I'm currently working on a synthetic biology project which involves working with lots of different parts. I would ultimately like to integrate these genes by transforming a single plasmid. I've heard ...
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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 !
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Scale up of Bacterial growth from 250mL to 1-5L?

I am currently growing up a specific strain of E.Coli with a knockout in 40mL of growth medium (LB) in a 250mL shaker flask... My ultimate goal is to scale up this process to a 1-5L large scale setup ...
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2k views

Why are pili more common in Gram negative bacteria than in Gram positive?

Although pili have been observed in some species of Gram positive bacteria, the preliminary research that I have done indicates that pili are significantly more common in Gram negative bacteria. Is ...
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449 views

Survival of E. coli on agar plate at -20 degree C without glycerol stock

If I kept E. coli transformed with plasmid at -20˚C without making glycerol stock, will it survive? Actually I have kept it this way for 18 hours. What will happen with it? Will it grow in fresh ...
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382 views

Aren't antibiotic resistant probiotics dangerous?

Multidrug resistant probiotics are often recommended by doctors in various cases. But since bacteriae can easily exchange genes by conjugation or other means they could promote the drug resistance of ...
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73 views

Are Lambic beers the product of quorum sensing?

Lambic beers are a Belgian specialty which is still made by open-air "inoculation" by airborne microbiota first, followed by additional yeasts, LAB bacteria and more joining in at the time of ...
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134 views

Mutation-immunity in Luria-Delbruck experiment

If experiments like those of Luria and Delbruck on E. coli and T1 phage are the main source of our confidence in the mutation-immunity model, is it then highly unlikely that there are other types of ...
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540 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, ...
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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 ...
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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 ...
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399 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 ...
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142 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, ...
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54 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 ...
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624 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, ...
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268 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 ...
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400 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 ...
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37 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 ...
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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 ...
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451 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 ...
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24 views

Ethanol production by fermentation?

As bacteria are involved in the production of ethanol through fermentation and ethanol is also used as antiseptic that kills bacteria, so how and why bacteria are involved in the synthesis of such ...
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45 views

Why don't all bacteria have F-plasmids by now?

Some bacteria can undergo gene transfer by conjugation. Conjugation is a form of horizontal gene transfer, meaning from one (unrelated) bacterium to another (in contrast to vertical gene transfer, ...
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61 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. ...
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58 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.
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181 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, ...
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41 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?
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385 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 ...
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35 views

To which negatively charged components of the cell envelopes do the crystal violet complexes bind in gram staining?

The gram positive have negative components in the peptidoglycan layer in the form of teichoic acid phosphodiester bonds, and the gram negative have negative components in their outer membrane in the ...
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83 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 ...
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74 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 ...
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88 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 ...
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128 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? ...
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172 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?
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141 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 ...
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99 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 ...
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77 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 ...
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168 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 ...
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91 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 ...
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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 ...
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81 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. ...
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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 ...
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92 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 ...
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107 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
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1answer
96 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 ...
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60 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 ...
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1answer
180 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?
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91 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 ...
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303 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 ...
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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 ...
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180 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 ...