9 votes
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Is hydrochloric acid suitable for pickling food?

Short answer Weak organic acids are more effective for food preservation then strong mineral acids, mainly because undissociated weak acids can cross the cell membrane and disrupt cell physiology from ...
AliceD's user avatar
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8 votes
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Meaning of "f.a." in the species name

"Forma asexualis" as explained in another paper The authors favor the use of the expression forma asexualis (f.a.) in the description of anamorphic species of the genus Cystobasidium and this ...
the gods from engineering's user avatar
4 votes

Earliest to use media after autoclaving?

There is a relatively simple (and yet logical) answer: You can use the media as soon as they are cold enough for your desired culture temperature. So if you want to use the media at 30°C, there is no ...
Chris's user avatar
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4 votes
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How can I measure the population growth of yeast?

The standard way to measure growth in a liquid culture is to measure the optical density (OD) of the solution – basically, how cloudy it is. Bacteria or yeast in a solution will absorb light that ...
divibisan's user avatar
  • 355
3 votes
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What is a "marker-matched" plasmid?

It is where a control plasmid is used - this is usually an empty vector or a non-target vector with the same "marker" on the plasmid. The marker is often one that is either used for ...
bob1's user avatar
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3 votes
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Can viruses stabilize and increase the shelf life of wine and other foods?

There is at least one bacteriophage ("phage") that targets bacteria that spoil wine: The Gluconobacter phage GC1 is a novel member of the Tectiviridae family isolated from a juice sample collected ...
Alex Reynolds's user avatar
3 votes

Is the CMV promoter active in yeast?

Yes (reference) While I found your question interesting this was pretty much the first hit when I typed "CMV yeast" in google scholar. You should really look there first before you ask!
mimat's user avatar
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3 votes

Where do kombucha SCOBYs get nitrogen?

Short answer: Nitrogen fixation (i.e, atmospheric nitrogen) Longer answer: Nitrogen fixation is the process by which atmospheric nitrogen is converted to forms usable by further biochemical ...
Bryan Krause's user avatar
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3 votes
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Can yeast survive without mitochondria?

Basic answer: Yes, they can survive, but only if they do not need to undergo cellular respiration. I quote from Microbiological Research, Volume 169, Issue 2-3, p. 185-195: Mitochondrial DNA (...
rotaredom's user avatar
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3 votes

How can I estimate the total number of yeast cell in a medium?

Determination of cell concentration using a microscope is usually done by using a hemocytometer, also called counting chamber or Neubauer-counting chamber. Basically, you count the cells in a defined ...
cako's user avatar
  • 141
3 votes

Enzyme Inhibitors: Using in vivo in yeast

This is usually the way this kind of inhibitors are used. There needs to be a way that they come into the cells (if they stay in solution and cannot reach their target they will be useless), but then ...
Chris's user avatar
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3 votes
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Why does yeast react the way it does to water combined with sugar?

Yeasts are living organisms, they do not evaporate. However it is true that in most fermented food we eat, yeast are no longer there. So why is it so? It is not the reaction with sugar and warm water ...
Flo's user avatar
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2 votes
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Yeast Strain with squalene synthase / farnesyltransferase (ERG9) gene deleted

Yeast strains have two mating types MATa (since it secretes a pheromone named 'a factor'), MATα (secretes pheromone 'α factor'). Both MATa and MATα strains are haploid and when they fuse together they ...
Ak2817's user avatar
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2 votes

Earliest to use media after autoclaving?

If not using antibiotics or other additives, it's just a matter of medium being cold enough. If it's too hot, the yeast (or whatever you are inoculating) might get killed or heat-shocked, which you ...
Superbest's user avatar
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2 votes
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Rice left in water for several months - what biological reactions or growths would occur?

It is likely a volatile organic compound (VOC) that is released as a by-product of microbial metabolism, although microbes can also produce some inorganic compounds, such as hydrogen sulfide (rotten ...
VVayfarer's user avatar
  • 258
1 vote

Reliable recipe to make DIY yeast slants

Yeast grows very well in liquid. The initial innoculum from the store will visible grow (“prove”) in warm water with a little sugar.
Polypipe Wrangler's user avatar
1 vote

Gene of interest number of copies in transformed K. pastoris

To predict the number integrations is probably not possible, but you can favor multiple integrations, if that's what you are after. At least in Saccharomyces cerevisiae integration of a first plasmid ...
gaspanic's user avatar
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1 vote

Does the process of making a sourdough starter involve Darwinian selection?

There absolutly is selection involved. First, you create a selective environment to culture a subset of environmental organisms (yeasts). Then, by infusing fresh media (flour/water) into the cultures ...
MikeyC's user avatar
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1 vote
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Does the process of making a sourdough starter involve Darwinian selection?

Yes, continually diluting the mix like this encourages the organisms (bacteria, yeasts, fungi) to have more constant conditions (maximum nutrients, fewer waste products) and be in log phase growth. ...
Polypipe Wrangler's user avatar
1 vote
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What are the best plants to cultivate yeast from?

Yeast colonize the surface of many plants — for example they are a typical part of the normal surface flora (microbiome) of fruits such as grapes1 and pears2. As you can see from the second reference,...
tyersome's user avatar
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1 vote

Continuous (yeast) culture system satisfying multiple criteria

A chemostat should satisfy your criteria. The cell mass balance around a chemostat is the following (assuming no biomass in the feed): $$F-FX+V_RX\mu_g-V_Rk_dX=V_R\frac{dX}{dt}$$ At steady state ...
Cell's user avatar
  • 11
1 vote

Can a plasmid cause cancer?

Canonically, bacterial plasmids will not replicate in eukaryotic systems, due to a lack of the necessary control (regulatory) elements which will lead to expression. It is possible though to ...
S Pr's user avatar
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1 vote

How to measure the length of mitochondria from z stack fluorescent microscopy image?

ImageJ is usually the standard software to measure cell characteristics, a little bit of a learning curve but there is a large suite of analysis methods and image adjustments/filters.
Tom V.'s user avatar
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1 vote
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Yeast contamination with fungus patch

Either you can cut out the fungus and get away with it, or the fungus will rapidly overgrow your plate regardless. You might as well try to cut out the fungus. If it overgrows your plate the ...
Willk's user avatar
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1 vote

How do I improve expression using the GAL1 promoter in S. cerevisiae above the "leaky" level I'm currently seeing?

There are a couple of things that are strange here. First, you have low expression in the presence of galactose. The GAL1 promoter is really strong, so that strikes me as odd. Even if it was leaky, ...
Hayden S's user avatar
  • 176
1 vote

Pichia pastoris and ornithine

Yes, it contains arginase. Thise enzyme converts arginine to ornithine and is probably part of the urea cycle. You might notice the arginase is listed as coming from Komagataella phaffii GS115, but ...
VonBeche's user avatar
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1 vote

Using PGAL10 promoter to overexpress specific yeast genes: How to?

You're right about them being promoters, although it would be useful if you posted the link to the source of the sentence that you cite, so that we can read exactly how they are being used. A fairly ...
Forest's user avatar
  • 1,879
1 vote

Why would yeast grow but not produce alcohol?

IMO, the answer to this one is (b). The reason is the (often overlooked) Pasteur effect: oxygen inhibits fermentation. The Pasteur effect occurs in many cell types, including skeletal muscle, brain, ...
user338907's user avatar
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