lab yeast
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I think they're pretty different from brewing strains. Why would you be interested in using them?
Yes, lab. strains are pretty different (genetic and phenotipically speaking) when compared to brewing strains. For example:
1. Most lab. strains are genetically modified by inserting (or deleting) gene markers. In this sense, many lab. strains can be unable to synthesize determined amino acids, which made then useful for lab. research;
2. Lab. strains are mostly haploid, with a single complete set of chromossomes (16 in total). In contrast, brewing strains can be diploids, aneuploids, or poliploids;
3. Lab. yeast strains belong to S. cerevisiae species. Brewing strains can belong to S. cerevisiae, S. pastorianus, and S. bayanus species (consider also S. pastorianus and S. bayanus are also hybrid species formed from the mating of different Saccharomyces species);
4. Lab. strains are unable to growth at lager temperature
But considering the OP, W303 is a lab. strain with auxotrophic genetic markers originated from selective mutagenesis and back-crossing. S288C is the prototype yeast strain used for yeast genome sequencing, and is derived from Sigma strains. New wild-type (WT) strains also included the BY series (BY4741, 4742, and 4743) and FY, which contain auxotrophic markers generated by gene replacement.
1. Most lab. strains are genetically modified by inserting (or deleting) gene markers. In this sense, many lab. strains can be unable to synthesize determined amino acids, which made then useful for lab. research;
2. Lab. strains are mostly haploid, with a single complete set of chromossomes (16 in total). In contrast, brewing strains can be diploids, aneuploids, or poliploids;
3. Lab. yeast strains belong to S. cerevisiae species. Brewing strains can belong to S. cerevisiae, S. pastorianus, and S. bayanus species (consider also S. pastorianus and S. bayanus are also hybrid species formed from the mating of different Saccharomyces species);
4. Lab. strains are unable to growth at lager temperature
But considering the OP, W303 is a lab. strain with auxotrophic genetic markers originated from selective mutagenesis and back-crossing. S288C is the prototype yeast strain used for yeast genome sequencing, and is derived from Sigma strains. New wild-type (WT) strains also included the BY series (BY4741, 4742, and 4743) and FY, which contain auxotrophic markers generated by gene replacement.
I have heard of people using S288C. Supposedly it produced something not entirely unlike beer.
You'd probably be best off using a diploid with no auxotrophies, and don't count on very high attenuation. I think most/all lab strains are also flo-, so don't count on any flocculation.
But why bother, apart from novelty value?
Novelty, they're easily accessed, they smell nice when growing on rich media, first steps toward making a fluorescent beer. Any reason, really. Isn't this the forum where someone documented fermentation of ovaltine? I'm a little surprised to be asked why.
The auxotrophy comment is interesting. I would expect that wort would be a pretty complete medium and they wouldn't be much of an issue. Is this the wrong impression to have, or is your comment just reflecting the thought that it'd be best to have something closer to a natural strain?
The major problem that I see in to make a fluorescent beer is the fact that the fermentation will be made by a GMO yeast (and this brings a lot of regulamentations and laws regarding the use of GMO for food fermentation).
BUT, in an experimental sense, the generation of fluorescence in beer should not be so straightforward as you possible thinking. First, I imagine that you will express a fluorescent protein in beer (e.g., GFP). So, you will need an integrative plasmid (as stated, wort should be plenty of nutrients, and this could lead to the lost of non-integrative plasmids with time, like episomal plasmids). After all, your integrative plasmid should contain the coding sequence of GFP cloned under the control of a strong promoter (and it should be constitutive in order to avoid the use of promoter-activating chemical compounds). Moreover, as you want a fluorescent beer, the protein should be excreted in the wort during fermentation, requiring the gene to contain a sequence coding extracellular signal fused to the protein coding sequence.
In addition, the fluorescent protein should be stable against different proteases excreted by yeasts after the active phase of fermentation (requiring a non-natural GFP construction).
Important to note that the protein should be fluorescent under visible light, which can be difficult with GFP and derivative proteins that are fluorescent only under ultraviolet light. Of course, there are fluorescent protein that works with visible light, but these proteins have a very complicated structure, which can impairs its expression in yeast. Assuming that you have the right plasmid construction, an stable and efficient mechanism for synthesis and excretion of fluorescent protein, an stable maintenance of protein even in the presence of proteases, so, it can work....
Phew....lots of work to do.....
BUT, in an experimental sense, the generation of fluorescence in beer should not be so straightforward as you possible thinking. First, I imagine that you will express a fluorescent protein in beer (e.g., GFP). So, you will need an integrative plasmid (as stated, wort should be plenty of nutrients, and this could lead to the lost of non-integrative plasmids with time, like episomal plasmids). After all, your integrative plasmid should contain the coding sequence of GFP cloned under the control of a strong promoter (and it should be constitutive in order to avoid the use of promoter-activating chemical compounds). Moreover, as you want a fluorescent beer, the protein should be excreted in the wort during fermentation, requiring the gene to contain a sequence coding extracellular signal fused to the protein coding sequence.
In addition, the fluorescent protein should be stable against different proteases excreted by yeasts after the active phase of fermentation (requiring a non-natural GFP construction).
Important to note that the protein should be fluorescent under visible light, which can be difficult with GFP and derivative proteins that are fluorescent only under ultraviolet light. Of course, there are fluorescent protein that works with visible light, but these proteins have a very complicated structure, which can impairs its expression in yeast. Assuming that you have the right plasmid construction, an stable and efficient mechanism for synthesis and excretion of fluorescent protein, an stable maintenance of protein even in the presence of proteases, so, it can work....
Phew....lots of work to do.....
I wouldn't count on typical wort being complete (or at least staying complete through the full course of fermentation).
Note also that S288C is mal-:
http://wiki.yeastgenome.org/index.php/Commonly_used_strains#S288C
That ain't gonna get you very far in an all-malt wort.
