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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What is effectiveness of methyl-alcohol as sporicide?

Methyl-alcohol is the weakest alcohol in terms of bactericidal properties. However, I have read that it also works as sporicide. What is the effectiveness of methyl-alcohol in killing the spores of ...
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50 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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239 views

E. coli not growing in liquid medium

We are regularly doing bacterial transformation and subculture from plate to liquid media to extract DNA. This usually goes very well and is straightforward, but occasionally, the colonies that grew ...
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27 views

Why do flagella form a bundle only when they rotate counterclockwise during chemotaxis?

During Chemotaxis in bacteria with flagella, the flagellar rotation dictates how the cell moves. If the flagella rotate counterclockwise, then they form a bundle at one end of the cell (---O) and ...
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313 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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21 views

Can tardigrades survive being eaten?

Compared to a tardigrade, the cockroach seems fragile. But can tardigrades survive the acidic environment of being eaten by most animals?
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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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51 views

What is the advantage of using plant-derived antibacterials rather than bacteria-derived antibacterials?

So obviously we have a big problem with antibiotic resistance. Most of our antibiotics originate from bacteria themselves (or are synthetic variations on scaffolds which originate from bacteria). I ...
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22 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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26 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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158 views

How much salt [NaCl] is too much in DNA precipitation?

In DNA extractions, how much is too much salt in a CTAB extraction buffer? Protocols hover around 2.5 molar; if you go over this (e.g. 25 molar), will you saturate your solution, and precipitate the ...
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37 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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76 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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65 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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75 views

The ring formation of ringworm

I know ringworm is caused by a fungus on the skin, nails or scalp but what causes the rash to form as a ring instead of like a normal spread out rash?
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83 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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330 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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39 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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45 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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42 views

How is the appropriately-stratified gut microbiome acquired in organisms performing horizontal transmission?

I am studying horizontal transmission of primary symbionts in insect reproduction. This reminded me of an earlier question I had asked, in which I learned that humans analogously acquired their ...
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24 views

Bacteria surviving a β-lactam antibiotic

What changes can occur in the cell wall of a bacteria for it to survive a β-lactam antibiotic? I think that because a bacteria possesses peptidoglycan in its cell wall, they are β-lactam sensitive, ...
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26 views

Is urine sterile? A reference request for evidence supporting sterility

There is a seemingly unfounded mantra that a person's urine is sterile who is not suffering from a UTI. So far I have found convincing evidence to the contrary; urine is not sterile. This poster ...
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20 views

How do microbes develop resistance to anitmicrobial peptides?

I would like to better understand how bacteria use the "strategy" of alternations to lipid A and membrane proteins in order to resist antimicrobial peptides of the immune system? It is my ...
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38 views

Of people who develop Alzheimer disease, are those people genetically predisposed to it?

I have read a lot lately about microbiological pathogens that are found in blood vessels in the brain of patient's with Alzheimer disease (positive association). So, I am confused whether there are ...
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11 views

Microbiology- Pseudomonas aeruginosa, BSAC data

I tested Pseudomonas aeruginosaagainst various antibiotics, using Stokes and Kirby-Bauer. When I compared my results with BSAC data it was completely different (understandable) but why for a lot of ...
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29 views

Values of Miu_max and Ks from parameter estimation?

Background I have this simple biomass growth model: $$ \mu = \mu_{max}\cdot \left(\frac{S}{K_S+S}\right) \cdot \left(\frac{1}{1+S/K_{iS}}\right) \cdot \left(\frac{K_{iP}}{K_{iP}+P}\right) \\ ...
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35 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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27 views

Enrichment of slow growing microbes: Large Test Tubes as an alternative?

Well, i would like to enrich bacterial and archaeal ammonia oxidisers from soil samples using Minimal Salt media. They are slow growing microbes. I would like to enrich them with the aim to produce ...
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21 views

Clumping factor test

I'm come across this question and I'm somewhat confused: In the test for staphylococci, the clumping factor detects: staphylothrombin DNase mannitol fermentation Fimbriae fibrinogen-binding protein ...
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19 views

What are the main principles of the Bacteriological Code?

Although the Bacteriological Code is an important guideline for taxonomists and microbiologists, describing the criteria for delineating species and higher taxa of the prokaryotes, I, and plenty of ...
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84 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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44 views

Alkaline Phosphatase

What is the predominant purpose of Alkaline Phosphatase in skeletal muscle fibers and liver cells. I know that it is a hydrolase enzyme that speeds up the degredation of proteins, lipids, starch and ...
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23 views

Can you change your gut microbiota by changing your diet? Would that affect calorie uptake?

I have seen peer-reviewed papers mentioning the daily changes in gut microbiota composition according to dietary changes. See for example this paper: http://genomebiology.com/2014/15/7/R89 My ...
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121 views

What is Mycoplasma Lyo medium?

Used for instance in this article The role of genital mycoplasmas as pathogens - - are generally neglected by diagnostic laboratories in the United Kingdom, possibly due to the lack of a ...
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83 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 ...
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55 views

Vitamin D oral intake, transportation and absorption

Several factors affecting vitamin D and its active form absorption and storage acidity of stomach (not significant effect) cytopathic effects of viruses cytopathic effects of bacteria where the ...
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44 views

How are lophotrichous flagella of helicobacter pylori produced?

I am thinking the mechanism is something like first adhesins (mucinase). Howevever, this does not seem to be enough. How are the flagella of H. pylori produced?
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75 views

What are current abiogenesis hypotheses for first food source?

What is the very first abiogenetic piece of reproducing life (small piece of RNA + ribosome that randomly occurred?) hypothesized to have used as an energy source? I'd be interested in sources to what ...
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Bacterial 16S rRNA PCR amplification with universal primers

I am doing an experiment to amplify the 16S rRNA gene from bacteria present in gut contents of fish. After extracting DNA, I perform one-step PCR with universal bacterial primers (27F, 1492R) and I ...
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52 views

Improving throughput of CFU plating?

In a separate question I've described my general experimental setup where I need to measure the number of live cells in a growing bacterial culture in a fairly rapid and high-throughput manner. In ...
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47 views

What are the characteristic structures of bacillus M. tuberculosis and what they cause?

I answered to this question: In most forms of the disease, the bacillus M. tuberculosis spreads slowly and widely in the lungs, causing the formation of hard nodules (tubercles) in the ...
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11 views

Tardigrade genetic acceptance and experimentation?

Does this property of tardigrades, that when under extreme conditions they are more permeable and more easily accept sections of genes developed in other species, as I understand sometimes transfered ...
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14 views

NMDS analysis - weird plots

I ran a NMDS analysis on 16S tag sequencing data on three different 16S regions, and would like to establish the regression coefficients (R, p) from this. All the data is stored within a combination ...
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6 views

using bioreactors for bacteria and yeasts

I have some questions about the OD to inoculate in a bioreactor and the OD for the induction using bacteria and yeasts (Pichia pastoris) to produce recombinant proteins. Which is the OD for the ...
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21 views

30s ribosomal Inhibitor (Antibiotic)Question

I have a question regarding the mode of action of 30s ribosomal Inhibitors (antibiotcs) - tetracyclines. According to some online resources, the antibiotics enter the A-site, which prevents other tRNA ...
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28 views

How do cell repair mechanism ratios change as they age?

I have seen that embryonic stem cells are shown to use homologous repair for double strand breaks rather then non-homologous end joining (NHEJ). [1] I am wondering if something also happens to a ...
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20 views

Oral Fordyce spots

This is an image of a Fordyce spot I found on Googling. I don't know how to interpret this image. Is this an image of a single Fordyce spot? Single as in a single spot when viewed with the naked ...
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16 views

What exactly are polyphenols and what benefits do they provide to humans?

I say somewhere that they are antioxidants, but I was wondering if the two terms are synonymous or if that is just one of many things polyphenols can do.
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Symbiosis of Pseudomonas Fluorescens

Have a modest background in molecular biology and presently considering a project that requires some knowledge of botany. Specifically, I seek details on the epiphytic relation between the microbe ...
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Counting of surface bacteria in real time

I'm fairly new to microbiology (okay, I'm forced to look into it for a group project). What I'm looking for is a way to quantitatively get an estimate of the number of microbes (bacteria and/or ...