Questions tagged [bacteriology]

A subdivision of microbiology dedicated to the study of bacteria.

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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?
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Have some lower order organisms evolved to grow below the freezing point of water?

I just learned that water sublimates, which prompts me to ask: Can lower order organisms (e.g. bacteria / fungi) grow below the freezing point of water?
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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 (...
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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 ...
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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 ...
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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 ...
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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 ...
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1 answer
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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) ...
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1 answer
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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 ...
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Are there any bacteria that could be used as food?

Bacteria are found everywhere. They can also grow on various substrates. Are there any bacteria that can be used as a food source? For example mix x with water and add some of these bacteria. These ...
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Identification of Mold / Fungus

I am working with some old plaster powder, and a few days after it set (mixed with water), I found that pink mold / fungus appears to be growing on it. See attached photo. Please help me identify what ...
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Why do bacteria denitrify?

Denitrification is the microbial respiration in anoxic condition. If the process is complete we have : $$2 \text{NO}_3^{-} + 10 \text{e}^{-} +12\text{H}^+ \rightarrow \text{N}_2 + 6 \text{H}_2\text{O}$...
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Why would E. coli cultures suddenly start to slow down?

My E. coli cultures used to take 13.5 hours to reach stationary phase. I have not changed any of the parameters like temperature, shaking speed, media formulation/components or inoculation volume. ...
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Would viral diversity result in a change in the effectiveness of CRISPR systems in a population of bacteria, within a closed system?

I have here my hypothesis, does this make scientific sense? Assume this situation is occurring in a closed environment with only bacteria and bacteriophages. The effectiveness of CRISPR/Cas9, being an ...
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Production of “Green Hydrogen” by photosynthesis

In a popular science book from the 1970s I read about experiments to tweak some microorganisms to produce elemental hydrogen by photosynthesis. Is this a feasible way to produce “Green hydrogen”? What ...
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I am conducting an experiment with oil eating bacteria. However, I am struggling to find a method to check how much oil they cleaned?

I am experimenting to determine the optimum conditions for microbes to break down motor oil. The conditions I am going to test are different pH levels to resemble freshwater pH and saltwater pH. I ...
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What type of bacteria can I use to break down motor oil for a high school biology experiment? Any suggestions where I can find this bacteria?

I am experimenting to determine the optimum conditions for microbes to break down motor oil. The conditions I am going to test are different pH levels to resemble freshwater pH and saltwater pH. I ...
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How does Clostridium perfringens cause target hemolysis?

I am studying microbiology as a part of my course and I was studying Clostridium perfringens. While studying its hemolytic characteristics, I came to know that it causes target hemolysis (i.e. zone of ...
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When was the germ theory officially accepted?

Is there a specific year that marks the official acceptance of the germ theory? In the references, it is always quoted the work of Pasteur, Koch, and Lister, but their work is spread over decades and ...
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How does Heat Fixing make the cells stick to the slide?

Today I learned how to do Gram Straining in my college and our instructor told us how we pass the slide with the bacteria on a bunsen burner 3-4 times and it fixes the bacteris so that it doesn't get ...
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How long is agar agar good for?

I'm a high school science teacher, and am starting at a new school. I'd like to do some labs with bacteria and so I'll need to make plates with agar agar. I found 3 huge jugs of powdered agar in the ...
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Recommendations for good books on bacterial genetics & molecular biology?

I'm starting a new phase of my PhD soon, and am feeling very under-prepared with respect to my general bacteriology knowledge. I was recommended to read up on basic bacterial genetics and molecular ...
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1 answer
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Can some bacteria eat soap molecules in soapy water rather than get killed by it? How do they hang on to their surface lipids? Evolutionary advantage?

In my Chemistry SE question Quantifying soapiness; there's pH, pKa and pO2, is there a p_soap or p_surfactance? I explained that when I am too lazy or too much in a hurry to do my dishes right away I ...
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How do viruses/bacteria survive in extremely cold conditions?

So, recently, i watched a video, it was about a anthrax outbreak in Siberia. The cause, supposedly were reindeer carcasses, infected by anthrax. Due to the thawing ice they resurfaced, and that lead ...
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Is there any possibility at all, that anything, bacteria, viruses, etc, can survive the plastic recycling process used for food and drink plastics?

The Question - Is there any possibility at all, that anything, bacteria, viruses, etc, can survive the plastic recycling process used for food and drink plastics ? Since I notice that some ...
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How does the first organism infected by a disease get infected?

How does a micro-organism causing some communicable disease infect the first organism it infected? I was reading about HIV, when I found that HIV has jumped from chimpanzees to human beings. But, how ...
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What is the normal flora in Respiratory Tract (Upper and Lower)?

I opened my notes and it stated : pharynx, trachea, bronchi : << flora normal bronchioli & alveoli : steril which I doubt because many papers I read stated that the lower-respiratory tract ...
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How does araC exhibit both positive and negative control?

I was of the understanding that negative gene regulation = active form of the repressor protein shuts off the operon and positive gene regulation = active form of the regulatory protein increases ...
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1 answer
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Is bacterial resistance caused by underdosing?

The phenomenon of antimicrobial resistance caused by overuse of antibiotics was predicted as early as 1945 by Alexander Fleming who said "The time may come when penicillin can be bought by anyone ...
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What chemical to use to recycle microplates used to grow bacteria

We grow bacteria (Escherichia coli) in polypropylene or polystyrene microplates with an optical bottom for some experiments (liquid culture). I would like to try and recycle those microplates to be ...
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Why are O-antigens and H-antigens on (certain) bacteria called O and H?

Somehow, despite extensive searching, I cannot find an answer.... Does O stand for oxygen and H signify hydrogen?
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Can antibiotic resistance cause problems for the microorganisms producing them? [duplicate]

My understanding is that antibiotics are naturally produced by microorganisms as a defensive measure against certain kinds of bacteria. For example, some Penicillium molds produce penicillin. Clearly, ...
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How to take professional SEM images of bacteria?

I am new to using SEM microscope I would like to take clear pictures of Bacillus subtilis. My sample is dropped on a piece of paper and carbon-coated. The picture is showing crumbs of something (maybe ...
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Why do bacteriophages look like tiny little robots? [closed]

I get it, evolution is funny and works in mysterious ways. But come on. You can't tell me this thing doesn't look like a nanobot. Why do bacteriophages look this way? With their cylindrical heads and ...
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If brine salt percentage is between 1 and 2 percent, can Clostridium botulinum growth prevail over Lactobacillus acidophilus?

After searching in various websites, I found mostly that Clostridium botulinum doesn't grow easily in a salty environment, and that it needs a pH from 4.6 to up; as I am lactic fermenting some bell ...
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Doubts about what is growing in my bacteriological cultivation

Foreword: I don't belong to the field at all, I am a high school student with a passion for science so I apologise in advance if I formulate the question incorrectly or make some mistakes. Out of ...
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2 answers
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Do bacteria produce proteins other than ribosomal proteins when grown in wrong culture media?

Someone I know has done an experiment using pure culture and given it to me for rna-seq analysis. But there are a few problems the bacteria she gave me as reference was initially a Staphylococcus sp. ...
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How does Propionibacterium acnes survive the antibacterial effects of sebum?

Sebum has antibacterial properties due to sapienic acid and oleic acid according to this article on sebum. According to the same article, desaturation of fatty acids increases acne development. ...
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Do bacteria select for "soap resistance"?

When people wash their hands with soap, this limits the spread of bacterial infections. That much, I am pretty convinced of. Duh. What I don't get is how this doesn't lead to evolutionary pressure on ...
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How typhoid fever severe case's intestine perforation occur? (non trauma)

In typhoid severe case, intestinal perforation occurs. As stated here [4, 6]. Intestinal perforation is a serious complication of typhoid fever My question here is, how does the bacteria (Salmonella ...
1 vote
1 answer
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How to measure the pH of a bacterial species?

I would like to calculate the pH of a certain bacteria species before after an experiment. I was reading about the pH cell of bacteria and I found out about Bacterial Intracellular pH which I ...
1 vote
1 answer
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Mutations in a Petri dish overnight

How long does it take for a bacterial culture in a Petri dish to experience all possible single base pair mutations? Can 12 hours be enough? I want to get an intuition for whether a given mutation is ...
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1 answer
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What is sigma factor PvdS?

I am using MEME suite tool for de novo motif discovery and when I use TomTom to compare my motifs with known motif database, I find that my genes could potentially be upregulated or downregulated by ...
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1 answer
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Is there any alternative to peptone and beef or yeast extract?

I am trying to start a small microbiology project and I need a growth culture for bacteria. I do not want to use the costly nutrient agars you can buy online. I would like to create my own nutrient ...
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Will proper autoclave treatment really "inactivate all resistant bacterial spores"? If not, how widespread are autoclave-resistant bacterial spores?

Wikipedia's says: A widely used method for heat sterilization is the autoclave, sometimes called a converter or steam sterilizer. Autoclaves use steam heated to 121–134 °C (250–273 °F) under ...
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What is the structure of PduK in the Pdu BMC?

My lab is creating 1,2-propanediol utilization bacterial microcompartments (Pdu BMCs) with an operon containing genes for PduA, PduB, PduJ, PduK, PduN, PduU, and PduT. According to Mayer et al., all ...
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Is it known how some heat-resistance Bacillus spores repair their DNA after having been heated to 420 °C? (but not much higher)

Background Discussions below several recent posts in Space SE (links below) indicate that bacterial spores are a serious problem when considering how to prevent a future spacecraft mission to ...
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Disposing biohazardous material

I had conducted some disc diffusion tests with E.coli and S.epidermidis. Now, I wanna dispose these petri dishes and was wondering the correct way to do it. Many websites mention adding bleach to the ...
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How to create long term stock for Bacillus subtilis?

I am trying to create a long-term stock for Bacillus subtilis (Bacterial glycerol stocks). I have looked online for guides and step-by-step tutorials and I found that they don't say where the sample ...
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When Bacillus subtilis form spores vs die?

In my understanding: sporulation in Bacillus subtilis involves the differentiation into two cell types, the endospore, and the mother cell. The endospore coat is a multilayered shell that protects the ...

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