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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Why do some bacteria have an asymmetric replication?

Our teacher said that Bacillus subtilis has an asymmetrical replication fork. I know that this happens only in some strain of the bacteria . She asked us to find an explication for this mechanism , ...
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Why are viruses considered microbes?

My question is simple. Why is a virus considered a microbe? Considering a microbe is considered to be a "living" unit of life, which viruses are not.
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25 views

Nucleoside analogs that cause mutation

I'm confused with this explanation in my book: 2-aminopurine is incorporated into DNA in place of adenine but can pair with cytosine, so an AT pair becomes a CG pair. This sentence seems odd to me. ...
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25 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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548 views

How heavy are all foreign microorganisms in and on the human body?

I define "foreign microorganism" as a microorganism which is not produced by the human body (not antibodies or leukocytes) including bacteria, viruses, fungi, biofilm aggregates or small lifeforms ...
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23 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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28 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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2answers
47 views

Blood testing for chlamydia

I am working with the bacterium Chlamydia trachomatis. The main test for this species is the naat test, which is based on amplification. But I would like to know how the bacteria affects the blood ...
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3answers
206 views

Can ampicillin resistant bacteria survive penicillin plate?

in my molecular bio class we were asked a trick question: If the bacteria has a plasmid with that grants it ampicillin ressistance, can the bacteria survive if placed in penicillin? I gave it a ...
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1answer
22 views

How can I interface cAMP signal or membrane potential from slime mold to an electrode?

I am very much interested in measuring cAMP (cyclic adenosine mono phosphate) signal and membrane potential from amoeba. Since I want to try this as a hobby, what are the basic steps I must do to view ...
2
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1answer
39 views

How many diseases can be linked to disruption in the microbiome of a human?

I was listing to the radio and heard recent research found a link between children and higher cases of asthma when certain bacteria are missing from the microbiome. How many other diseases can be ...
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31 views

Soy kefir that never revitalises in animal milk

If I have kefir grains from goat and I make soy kefir and never revitalise the kefir grains in an animal milk, will that bacteria still be beneficial for the gut? What type of bacteria does it make? ...
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153 views

How does Cro protein expressed by lambda phage kill its host?

I read that the DNA segment of lambda phage integrated in host DNA could switch between lysogenic state where cI represses the expression of Cro and lytic state where Cro expression takes over and ...
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820 views

Are all pathogens parasites?

If parasites are organisms that feed on other living organisms, then aren't all pathogens parasites? I've emphasised on 'feed' because I guess the pathogens just eat us (i.e. take nutrients to ...
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1answer
61 views

What are the differences and similarities between fimbriae and adhesins in microbes adherence factor?

Adherence factors in microbes is to attach to a host cell or to an extracellular matrix. So what is the difference and similarities between fimbriae and adhesins?
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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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163 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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80 views

Ways to fight black mold

Is it possible to introduce a microorganism to a colony of black mold that will kill off the black mold entirely and permanently? Is there a common microorganism that likes to eat them and is harmless ...
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74 views

How do single-celled predators chase other cells?

From my understanding, single celled organisms have been seen avoiding, and chasing, potential food or other organisms. How do they accomplish this? They do not have eyes or ears or a nervous system. ...
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1answer
59 views

What is the simplest autotrophic cell?

Very simple cells, such as Nanoarchaeum equitans, require a host to provide certain essential ingredients for life. Complex life-forms (like humans) require a whole ...
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1answer
103 views

Identification of black growth on onion skin

I have encountered this black-colored growth on onion skins a lot. It seems to develop over the course of weeks and I have rarely, if ever, encountered the material on fresh ones. If I peel the onion ...
3
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1answer
72 views

How does botulinum toxin enter the blood stream from the digestive tract?

To my understanding, large polypeptides such as botulinum toxin cannot pass the intestinal lining intact. How, then, can it enter the bloodstream and cause botulism poisoning?
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68 views

Why lab technicians use indirect (antibody reaction) method for diagnosing?

In microbiology we have two types of microbial diagnosis. The direct method is where we detect the invader's DNA, Antigens or culture to see the exact pathogen while the second, indirect, method is ...
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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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177 views

What are the most important factors influencing a person’s gut microbes?

You are your bacteria! The probiotics and the antibiotics... There has been on going discussions about how our gut bacteria is important for a healthy lifestyle. Figure 1: Schematic diagram ...
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39 views

Cellulose acetate membrane filters vs. glass microfiber filters

At equivalent pore sizes and pressures, which exhibits faster flow rates, cellulose acetate membranes or glass microfiber filters? I know cellulose acetate exhibits low protein binding, but what ...
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50 views

Spatial learning in microorganisms

Has there ever been an experiment performed that demonstrated a form of 'spatial memory' in a unicellular organism? I'm imagining something analogous to the classic 'rat in maze' experiments, but ...
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235 views

Autotrophic and heterotrophic organisms in anaerobic condition

Can both heterotrophic and autotrophic organism survive in anaerobic conditions? If an autotrophic organism does not produce carbon dioxide but requires oxygen, it should not be present in anaerobic ...
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Is there an advantage to antibacterial soap?

There are plenty of different hand soaps out there, as well as hand sanitizers. Is there an advantage to soaps that claim that they're antibacterial vs soaps that just say soap? In particular I'm ...
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77 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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1answer
2k views

Bacterial capsule vs. slime wall

I've read that the bacterial capsule protects the bacterium from phagocytes and prevents water (and nutrients, possibly?) leakage from the bacterium. A less organized and less dense version is called ...
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4answers
2k views

What is the difference between a spore and a cyst?

Last year I read a course in biology. During that course I learnt that Protozoa like Lamblia intestinalis or Entamoeba hystolitica form cysts in unfavourable conditions. This year I read a course in ...
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932 views

Why is triclosan not considered an antibiotic?

Triclosan is a chemical often referred to as a "biocide" instead of an "antibiotic". However, its mode of action seems to suggest that it is an antibiotic. Triclosan binds to bacterial enoyl-acyl ...
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66 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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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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104 views

Why increasing the vector concentration does not increase the effeciency of bacterial transformation?

I was reading some old description of the protocols used for the transformation of bacterial cells. In the description I read that the transformation works best with low amount of DNA, and if we ...
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1answer
117 views

What can cause a lump in the middle of the neck? (homework case study) [closed]

What can cause an erythematous, fluctuant, nontender mass in the middle of the neck? Full Case Study: (Its the last of 6 cases and I just can't figure this one out, because of all the possibilities, ...
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51 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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162 views

What is the difference between electrons and energy? [closed]

I'm studying microbiology right now and I have come across something confusing to me. I thought electrons provided energy to the cell by being incorporated into reducing powers and eventually driving ...
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1answer
63 views

What does the term “relay competent” mean?

I was reading the article of Dallon & Othmer (2010) which deals with cell aggregation in Dictyostelium discoideum. In the introduction of the paper it is said that cells becomes "relay competent". ...
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1answer
5k views

Inoculation vs. vaccination

Is there any actual difference between inoculation and vaccination or are these terms interchangeable? In case the difference exists, would it be correct to say that inoculation is purposefully ...
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246 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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122 views

Can the Staph streak method be used for culturing Neisseria on blood agar?

What I learned in class: Normally chocolate agar is needed to grow Haemophilus and Neisseria. The Staph streak technique can be used for culturing Haemophilus on blood agar by allowing the Staph to ...
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2answers
143 views

Why do slime molds pulsate when growing into their fruiting body?

An example can be seen in this Youtube video, where the slime mold pulsates as it engulfs a rock in order to form its fruiting body. Why does this pulsing happen?
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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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152 views

When do plasmids replicate relative to its host cell cycle?

For plasmids is so much shorter than their host cell's genome (about 1/1000 in my case), it will take only 1/1000 time for it to replicate. With respect to cell cycle, when will that replication ...
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78 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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2answers
3k views

Does freezing microorganisms such as probiotics kill them?

Does freezing microorganisms such as probiotics kill them? If not, what is the process that allows them to "come back to life" after the temperatures are increased? As an example, lets say you ...
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286 views

Are there single-celled organisms that have evolved from multi-cellular ones?

I'm reading this paper about transmissible cancer cells in clams (Metzger et al. 2015) and I was wondering if there are any single-cellular organisms that are around today that are suspected as having ...
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99 views

Microalgae without cell walls?

Most microalgae have rigid cell walls. Dunaliella Salina is a pretty famous example of an algae with no cell wall, but just a plasma membrane. Are there any other microalgae without a cell wall?. I ...