Questions tagged [microbiology]

Microbiology is the study of extremely small organisms. This includes organisms like bacteria, fungi, protozoa, and viruses.

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142 views

Found in blood sample - what is it? Hopefully not a nemotode-

After examining someone's blood - through microscope - I found these. There were some more that were not photographed. Could someone please inform me on what these are? Maybe abiotic material on the ...
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1answer
178 views

EnteroPluri test contamination

An EnteroPluri test has twelve different sectors. It seems odd to me that pulling the inoculating tip from the starting sector (citrate) all the way to the ending sector (glucose/gas) and then ...
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812 views

How can I keep pond water “alive”?

I've been preparing wet slides for my kids to look at from pond water. I have a mason jar of pond water. What can I do to keep the microbes in the jar alive going forward so that we can look at it any ...
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100 views

When and How do pacemaker cells develop during the cell aggregation process of Dictyostelium discoideum?

I was reading a paper by Tang & Othmer about oscillations and waves in Dictyostelium discoideum. Under certain condition like starvation period in the life cycle of a Dictyostelium discoideum ...
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78 views

How can Haemophilus influenzae survive and grow alone in the human body?

Haemophilus influenzae gets its name from the fact, that it requires nutrients from blood in order to grow. More specifically, I see it mentioned that in vitro they often exhibit the pheomenon that ...
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66 views

What disease does Saccharopolyspora erythraea cause?

For an examination assignment I have to find a disease caused by the bacterial species Saccharopolyspora erythraea, but I have searched the internet and have found no report of patients being infected ...
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297 views

In bacterial conjugation, how do F+/F- cells detect each other?

I've just learnt about bacterial conjugation and while it is interesting info about early sexual activity in microbes, one aspect confuses me and doesnt seem to be mentioned in the material I read: ...
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771 views

What decides whether an ulcer/chancre is painful or painless?

In sexually transmitted infections, it is important to differentiate a painful ulcer from a painless one. This is because painless ulcers are seen in the chancre of primary syphilis while painful ...
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140 views

Does alpha-amylase from different species have different *optimal* conditions?

Do the optimal conditions for the enzyme isoforms differ between species? Specifically, do the optimal pH and temperature for alpha-amylase differ for that enzyme produced by B. lichiniformis and A. ...
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177 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 ...
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212 views

CRISPR-Cas Systems

In the context of the bacterial systems (not the gene editing tool), I was wondering what happens to the foreign DNA after the Cas proteins have created a new spacer. It is really not clear to me, ...
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735 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 ...
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2answers
76 views

Can a bacterium express a virulence gene and not produce toxins and what may be the cause of this?

I am preparing a seminar on viable but non-culturable (VBNC) state in bacteria, mainly foodborne pathogens and I just saw this line in a journal article by Lothigius et al that "the expression of the ...
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31 views

Can human pathogens present on plants become plant pathogens?

Since human pathogens sometimes live on the surface of plant leaves(read here and and here), and there are plant-pathogen microbes also living on leaf surfaces, is it possible for plant virulence ...
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159 views

Paper shows 2 hours of high humidity and hot temperatures kills corona virus, does this stop the spread of the virus?

I found this paper (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2863430/) which says these corona virus strains live for months at 4 degrees C, 20% relative humidity. But at 40 degrees C and 80% ...
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26 views

A question about dicumarol

I know that dicumarol was discovered in moldy sweet clover as it caused hemorrhage in cattles, but if someone had thromboembolic disorders causing uncontrolled thrombosis,would it be fine to eat moldy ...
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39 views

Volvox Cellular Reintegration

A couple of days ago, I answered this question over on worldbuilding.SE with some information about volvoxes, and commenter Liam Proven pointed out that one of the claims I made was dubious. I had ...
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44 views

How to grow a spirulina biofilm on a carbon/graphite cylindrical cathode?

I am trying to grow a spirulina biofilm on my cathode for a fuel cell but it doesn't seem to be sticking to the cathode. I have a culture of spirulina and I've submerged a few cathodes in it to try ...
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16 views

How do I determine an acceptable $F_0$ value in sterilization?

Here's a sample question: The sterilization process using moist heat is used to kill B.stearothermophilus by heating to 115 degrees C and holding it for 30 mins. For B.stearthermophilus, it ...
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61 views

Can a plastic degrading bacteria science fair project be recreated in a school lab?

i am just looking for a science fair project and am fascinated by this topic. i was wondering if a project concerning the isolation of plastic degrading bacteria could be done in a school lab. I am in ...
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2k views

What is the difference between enrichment media and selective media?

Enrichment media These media are used to suppress commensal bacteria while allowing the pathogen to remain viable and grow. [Source: Ananthnarayan and Paniker's textbook of Microbiology.] ...
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67 views

Can we investigate the cell biology of extinct microorganisms?

I know that there are microfossils, but not if we can we know about the organelles, genetics or macromolecules of the cells that left them behind.
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64 views

Does Penicillium roqueforti produce penicyllin?

I have recently discovered that blue cheese is produced with Penicillium roqueforti. As I know that some Penicillinum sp. produce penicyllin I wonder whether it is produced by P. roqueforti too? The ...
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155 views

Why did my isolation streak of an unknown organism on Mannitol Salt Agar turn yellow where there was no growth and magenta where there was growth?

I repeated a culture twice in an entry level microbiology class for our final lab project of culturing a provided unknown organism. One of the required tests on our dichotomous key was to culture a ...
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42 views

What is R.ornitholytica? Is it a misspelling of R.ornithinolytica or a different species?

I'm trying to find out which of these is correct, or whether they are different organisms: Raoultella ornithinolytica Raoultella ornitholytica I have come across ...
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536 views

Why are the most heat tollerant organisms prokaryotic?

Prokaryotic organisms are able to grow at far higher temperatures than are eukaryotes. Archaea are known to group, among some mesophiles, the most extremophiles organisms (es. Pyrococcus furiosus), ...
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62 views

Oxygen Uptake Rates in Microbial Cultures

Normally if air is sparged into a fermenter, the oxygen uptake rate is roughly equivalent to the oxygen transfer rate: KLa(C* - CL) = Xμ/YX/O2. How would this equation change if the oxygen ...
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48 views

Would canines that consume the stomach of ruminant prey animals benefit from any of the bacteria and enzymes present in the rumen?

This question is inspired by the growth in popularity of raw diets for pet dogs. Green tripe is a common addition to these diets, with many claims of probiotic benefits. Here's an example from a ...
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96 views

How to keep activated sludge viable for a week?

I am working in biological waste water treatment and I need to collect some activated sludge samples and have them characterized through different methods. The characterization will take from a few ...
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279 views

Light microscope specimen size

I was going through sample questions for Science Olympiad, and one of the questions went like this: A cell is observed through a light microscope at 4x magnification. The cell takes up about half ...
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77 views

Challenges of Industrial-Scale Fermentation

I was reading the wikipedia article on industrial fermentation, and it mentions that It is well established in the field of industrial microbiology that what works well at the laboratory scale may ...
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1k views

Can viruses replicate in a cell that's already dead?

Suppose a virus randomly lands on a cell that's just lying around. This cell may have just recently died, or died a while ago. This cell may also be part of tissue of a dead organism.* Does the virus ...
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807 views

Prevent clumping of bacteria in my media so that I can measure turbidity?

Forgive my naivety, I'm an undergraduate Chemical Engineering student doing research this summer into growth rates of various combinations of bacterial isolates. I have about 9 isolates from a toxic ...
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38 views

How would one identify cellular transcription factors associated with a viral protein in a treated cell line?

I've been working as the computer guy for a microbiology lab for the past few months. I've always been interested in bench work, but my wet lab experience is rather limited and thus so is my ...
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65 views

Lifeforms concentrations of the categories of macromolecules, and Lipids

Lifeforms are formed of large, modular, organic molecules called macromolecules, large organic molecules called Lipids, and simpler molecules such as H2O. Macromolecules are commonly grouped into the ...
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45 views

How to identify genes in Ralstonia that synthesize PHB and promote granule formation?

The compound polyhydroxybutyrate (PHB) is of considerable industrial interest as a biodegradable substitute for plastic. PHB is synthesized from glycerol by the bacterium Ralstonia eutropha. PHB ...
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104 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 ...
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48 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 ...
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212 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 ...
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38 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 ...
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192 views

Effect of flask position in shaking incubator affects growth kinetics

During some cultivation experiments for my bachelor thesis I noticed that in liquid culture my bacteria (E. coli) grew differently, according to the position in the shaking incubator. Because the ...
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151 views

Regulation of Cra protein level in E coli

Catabolite Activator/Repressor, Cra protein (formerly known as Fructure Repressor FruR) plays a significant role in central carbon metabolism of E coli. Its activity is inhibited by fructose-1,6-...
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287 views

What are the ingredients of Pheromone Trap using for controlling Fruit flies of cucumber?

Pheromone Traps are used for fruit fly control. But I have no idea which ingredients or chemicals are used for preparing Pheromone trap
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497 views

Image Processing Suite for bacterial microscopy: Schnitzcells or MicrobeTracker?

I am looking to start doing some work tracking the size and growth of individual bacterial cells in the microscope. In order to analyze the images I need software that can segment the cells, ...
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0answers
53 views

Elevated transaminases after blood transfusion?

This sparks HCV immediately in my mind. However, there may be other possibilities too. What can you deduce from elevated transaminases if you only know that the healthy adult patient received blood ...
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52 views

Endophytic Xylariaceae: diversity and taxonomy inferred from rDNA sequence analyses

"Thailand is considered as one of the areas containing a high percentage of unknown taxa of Xylariaceae (Rogers 2000). In Thailand, several studies on endophytic fungi have been documented, namely, ...
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1answer
784 views

What is this grainy surface on my two-week-old sourdough starter?

I'm baking bread at home as a hobby, using sourdough. After skipping one baking day, I haven't used my sourdough starter for two weeks. When opening the jar in which I keep it, I saw the surface had ...
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Does thimerosal have some of the same mechanism of action as sodium benzoate?

I noticed that thimerosal's molecular structure is basically just sodium benzoate with an attached chain that includes a mercury atom. Sodium Benzoate Thimerosal The Wikipedia article for thimerosal ...
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25 views

Why Vibrio Cholera produce its toxins?

I was wondering, why V. Cholera synthesize toxins which induce in humans diarrhea? I know that diarrhea is protective mechanism for humans, to get rid of bacteria. But why V. Cholera just stop ...
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When purifying plasmid DNA after cloning, do you get endogenous plasmid in addition to your vector of interest?

Since bacteria naturally contain plasmids, when you do a cloning experiment and purify the plasmids at the end, do you get plasmid naturally present in that bacteria in addition to your vector? The ...