Questions tagged [bacteriology]
A subdivision of microbiology dedicated to the study of bacteria.
678
questions
1
vote
0
answers
20
views
Can Gravity convection incubators negatively affect the growth of strict aerobic bacteria?
Background
Gravity incubators rely on natural convection for heat distribution. There is no fan or blower system, and the heat rises from the heating element at the bottom of the incubator.
https://...
- 197
0
votes
0
answers
12
views
Can a gene transfer from plasmid to bacterial chromosome?
Plasmid is involved in providing resistance to antibiotics. So, can that gene or any other gene transfer from plasmid to bacterial chromosome?
Is there any chance where antibiotic resistance is ...
1
vote
1
answer
73
views
How can Clostridium tetani proliferate in relatively minor wounds?
It is often reported (NIH) that some of the most common infections by Clostridium tetani are in minor wounds where, in theory, blood (hence oxygen) supply should not be completely disrupted.
How can ...
- 155
0
votes
0
answers
20
views
Storage of bacteria in MgCl2 at 4 degrees
I have a small question to which I am unable to find a proper answer.
Will bacteria in a MgCl2 buffer (or similar solution) at +4 degrees Celsius survive storage for 1-2 days? Or will they die?
What ...
- 176
0
votes
2
answers
61
views
How can one store non-sterile culture media in dissolved form in the refrigerator?
How do I store non-sterile culture media in dissolved form in the fridge in a clean but non-sterile container?
The powder of the media (Broth, Nutrient agar, MAC, or MH agar) will be put in a glass ...
- 197
1
vote
1
answer
39
views
How do i create sustainable readily available stock cultures to act as Gram stain controls?
My investigation on the matter
Ref #1
Staining known Gram-positive and Gram-negative organisms on either
side of your unknown organism act as positive controls for your
technique.
(Microbiology ...
- 197
1
vote
1
answer
61
views
Can a non-pure culture be used for reliable rapid phenotypic diagnostic tests?
Can a non-pure culture be used for reliable rapid phenotypic diagnostic tests (e.g. catalase, oxidase & gram stain)?
"Slide Test Method
Obtain a pure culture of the organism to be tested. ...
- 197
0
votes
0
answers
19
views
Ames Assay Confusion: Aren't the odds of spontaneous revertants too low to be able to accurately test the mutagenicity of certain compounds?
I am a student conducting a test with the Ames Assay. This assay uses a strain of bacteria that has a mutation in an amino acid synthesizing operon, which doesn't allow it to synthesize its protein. ...
- 1
3
votes
1
answer
918
views
Why are my bacterial smears disappearing?
I'm trying to inspect simple stained bacterial smears. But my smear suddenly disappears after a successful inspection with the oil immersion lenses.
The background can become too red (the color of the ...
- 197
0
votes
0
answers
29
views
What could be the cause of strange brown discoloration around some bacterial strains' colonies on macconkey agar?
Acinetobacter
Unknown (Yellow TSI, Oxidase negative, Catalase positive)
Unseeded plate
My only guess is that the initial pH of the poured agar is too acidic (too red), so any alkalinity is more ...
- 197
0
votes
1
answer
82
views
How do microbiologists decide whether two morphotypes on the same plate belong to the same strain?
Background
Colony: A colony, in microbiology, is a visible cluster or mass of microorganisms (such as bacteria or fungi) that has grown and multiplied on a solid agar medium. Each colony represents a ...
- 197
1
vote
1
answer
120
views
Is there a reliable method to determine if heat fixation was inadequate before proceeding with further staining steps?
Background
Heat Fixation: Heat fixation is a technique used in bacteriology and other biological sciences to affix bacterial cells or other microorganisms to a microscope slide. This is achieved by ...
- 197
1
vote
0
answers
16
views
Carbon dioxide concentration in alkaline media
I am running a batch experiment using penicillin bottles where I have bacteria growing for 21 days in a highly alkaline media (pH 10). I am measuring the CO2 and O2 content in the headspace over time, ...
- 144
1
vote
1
answer
63
views
Does cooking kill all bacteria?
So I know that the general rules is that pathogen prone foods such as chicken shouldn't be consumed after 2 hours at room temperature. Cooking meat such as chicken is necesary as it kills the ...
- 184
0
votes
0
answers
11
views
How do the qualitative tests for E.Coli work, which chemicals are used?
There are test kits that to detect E. Coli in water, by mixing a small sample of water with a certain chemical. After a certain time, the sample changes color depending on the presence of E. Voli ...
- 754
0
votes
0
answers
19
views
How can one use motility testing as a practically reliable test for organisms identification in bacteriology?
Background information:
The motility test is used to determine whether an organism is motile or non-motile. There are three types of bacterial motility *:
Active movement: true motility that we are ...
- 197
1
vote
1
answer
60
views
Can single-Use Gloves carry bacteria on their outer surface?
In bacteriology, can I touch items (e.g. oxidase discs) with my gloves not fearing to contaminate these items?
Are these gloves (e.g. Disposable nitrile gloves) made so that bacteria can't adhere to ...
- 197
0
votes
0
answers
20
views
What's the grade of D-glucose that can be used in glucose assimilation test in bacteriology?
Background information
Carbon assimilation test is based on the ability of a bacterial species to utilize an organic compound (e.g. D-glucose) as a sole carbon source.
This means that for carbon ...
- 197
0
votes
1
answer
54
views
Can I have LAMP on the bench / in the field?
I am interested in LAMP for detecting small amounts of DNA (loop-mediated isothermal amplification and yes, I know the initials don't match).
I am trying to figure out exactly how clean/(sterile?) ...
- 373
1
vote
0
answers
22
views
What is the mechanism behind antibiotic resistance and how can it be mitigated or prevented? [closed]
What causes antibiotic resistance, and how can we combat it? I am interested in the mechanisms behind antibiotic resistance and strategies to prevent it in bacteria.
- 11
1
vote
1
answer
44
views
A DNA extraction protocol that is equipment-less for bacterial metagenomes?
I am going into the field soon to sample a very remote environment. For reasons that are unimportant here, I would like to extract bacterial DNA from these samples in the field.
I will have access to ...
- 125
0
votes
0
answers
29
views
Can you perform D-glucose assimilation test for a bacterial strain without API kit?
Background facts:
Glucose assimilation test is based on the ability of a bacterial species to utilize glucose as a sole carbon source. The test is designed to determine whether the organism can use ...
- 197
1
vote
1
answer
71
views
Why do bacteria in a urinary tract infection (UTI) cause bleeding?
It seems that when a urinary tract infection happens, bacteria will cause inflammation to the lining of the urinary tract, and this will cause bleeding.
What is the exact process for the inflammation ...
- 113
1
vote
0
answers
19
views
Endospores contact with surfaces
I am currently studying endospores-forming bacteria. To be specific B.subtilis. I noticed that the formed spores have strong contact "grip" with the surface it is forming on. For example, ...
5
votes
1
answer
81
views
Why isn't bacterial colony a monolayer?
I am an engineer entering the field of microbiology. I was watching bacterial colonies (lab strain E. coli to be specific) being grown on agar plates. I was surprised that the bacterial colony was not ...
- 153
2
votes
1
answer
48
views
How can a layperson get their hands on a specific strain that's not readily available commercially?
I'm mostly interested to get my hands on L.plantarum D-103, but there are a few other strains as well. D-103 is e.g. mentioned here https://meridian.allenpress.com/jfp/article/80/10/1682/199965/...
0
votes
1
answer
35
views
How to figure out growth/culture conditions for a specific strain?
Specifically, I'd like to find out how to grow ME-3 L.Fermentum (DSM 14241) at home without any fancy equipment.
What food does it need? Sugar? Lactose? Something else? At what temperature does it ...
0
votes
0
answers
44
views
Methods of denaturing BL21 E.coli other than using lysis buffer and sonication
The goal is to try different denaturing methods for BL21 E.coli. However, finding detailed paper on this is challenging as most articles do not seem to include the details of their denaturing ...
- 1
0
votes
0
answers
57
views
Superbugs in eusocial animals
I am not a biologist, and I'm interested in eusocial animals, and the porous habitats in which they live. I know few facts about diseases in these animals: I know some interesting instances of viruses,...
2
votes
1
answer
44
views
What is the easiest way to determine the species of non-tuberculous mycobacteria?
We have isolated a mycobacterium strain from patient sputum using an NTM Elite plate.
When inoculated into an MGIT tube, we observe fluorescence when observed under UV light, which means it is highly ...
- 249
5
votes
1
answer
84
views
What's the purpose of using more than one culture medium for bacterial isolation?
What's the purpose of using more than culture medium for bacterial isolation?
Why not use just one?
If this is not generally used in isolation of various types of bacteria, I'm concerned especially ...
- 197
1
vote
0
answers
21
views
How are spacer sequences created in a prokaryotic genome?
The CRISPR/Cas defense mechanism uses spacer sequences between palindromic repeats to search for the sequence to cut by an endonuclease. But how are these spacers created?
Let's take Bacteriophages, ...
- 35
7
votes
1
answer
420
views
Has there been evidence that there has been coevolution in E. Coli strains with the T4 bacteriophage?
According to Evolution of T4-related phages, there have been multiple instances of evolution in the T4 coliphages. Per the article, there are many T-even phages that have insertions from other ...
- 73
4
votes
1
answer
525
views
Doesn't pasteurization kill gut bacteria such as Akkermansia muciniphila?
I've recently watched two presentations on YouTube (this and this) about Akkermansia municiphila, a commensal bacteria that feeds on the mucus of the gut.
What I find confusing is their claim about ...
- 188
1
vote
1
answer
66
views
Naming the Rings of Flagellar Structure
I will apologise ahead of my very basic question.
I just read about Flagella Structure and learned that there are 4 rings, namely "L Ring", "P Ring", "MS Ring", "C ...
- 297
5
votes
1
answer
484
views
Why does adding calcium chloride aid in bacteriophage infection?
We are attempting to isolate bacteriophages from environmental soil samples and most protocols recommend adding CaCl2 to the media to aid bacteriophage infection, even though they all recommend ...
- 249
4
votes
1
answer
115
views
Why would it be impossible for gram-positive bacteria to store sulfur as gram-negative sulfur-oxidizing chemolithotrophs can?
I have a question that I am not sure what is the correct answer on <<Brock's Biology of Microorganisms>>
When the book introduces "Cell Inclusions", there was a mini-quiz that ...
- 297
1
vote
0
answers
17
views
What prevents the diffusion of proton gradient in Gram (+) bacteria [duplicate]
The proton gradient in bacteria is important to power FTPase and flagella. How do Gram (+) bacteria maintain a proton gradient without a periplasm (Gram (-)) or intermembrane space (mitochondria). Why ...
0
votes
0
answers
31
views
How does the cell-wall ultrastructure of gram negative bacteria justify it being unable to Sporulate?
The following is a quote from my Microbiology Lecture PPT: "Some gram positive bacteria but NEVER gram negative ones produce spores under harsh conditions".
It got me wondering why gram ...
- 9
0
votes
2
answers
104
views
Is there a way to relate the OD to cells/mL without doing a standard growth curve?
I am helping out with an experiment with multiple bacterial cultures (>20 species). I need to a very specific concentration (cells/mL or CFUs*/mL) for this purpose. Unfortunately it appears that ...
- 176
-3
votes
1
answer
69
views
Understanding the names of microorganisms of the normal body flora
I'm taking an introductory course to microbiology and immunology, and i have been required to memorise the following microorganisms of the normal flora.
I'm trying to understand before I memorise, and ...
- 9
1
vote
1
answer
85
views
What are the W and DSM codes for the following bacteria referring to?
In this paper the following bacteria are listed:
Bifidobacterium bifidum W23 (DSM 26331)
Lactobacillus salivarius W24 (DSM 26403)
Lactobacillus acidophilus W37 (DSM 26412)
Lactobacillus casei W56 (...
- 121
1
vote
2
answers
44
views
Methods to obtain the mass distribution of an ensemble of bacteria?
Are there any mainstream methods to obtain the mass distribution of a bacterial population?
What kind of assumptions to they make?
Could anyone point me to some references?
- 125
2
votes
1
answer
145
views
Where in the biological realm is vitamin B5 chiefly produced?
Can yeast produce pantothenic acid (vitamin B5)?
Do bacteria efficiently produce it?
Or does it only come from plants?
The Wikipedia page for pantothenic acid doesn’t seem to answer the question (...
- 133
0
votes
2
answers
477
views
How would you measure the diameter/radius of a non-circular bacterial zone of inhibition?
Typically when we're testing the antimicrobial effects of some substance on bacteria growing on an agar plate, we get the area or diameter/radius of the zone of inhibition. But what do we do in cases ...
0
votes
1
answer
44
views
Beneficial effects of the fungi of a termite mound on the diseases suffered by the termites
My motivation to join this Biology Stack Exchange is the article by David Pride that I've read from the Spanish edition of Scientific American, that's Investigación y Ciencia. The article is [1], and ...
2
votes
0
answers
57
views
Setup of terrarium for an early life experiment
I'm building a terrarium in which an early life environment will be simulated. Over multiple years a few experiments with different starting molecules/atoms will be held in it. The selected materials ...
0
votes
0
answers
57
views
What nutrients are necessary for Bacillus subtilis germination?
What are the necessary conditions to germinate Bacillus subtilis spores? Under laboratory conditions, spores of B. subtilis are often heat-activated for 30 min at 70°C to increase their germination ...
- 23
-2
votes
1
answer
94
views
Does centrifuging the bacteria culture removes bacteria leftovers?
Usually, we centrifuge bacteria culture to either replace the media, control its density (OD), ..etc. I know that when centrifuging the cells are pushed to the bottom while the media (solution) ...
- 23
-2
votes
1
answer
90
views
Is bacterial respiration a continuous process?
Respiration in micro-organisms is the process of releasing energy from food. There are two ways of doing so: Aerobic respiration occurs in the presence of oxygen and produces ATP from the complete ...
- 23