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Re: Still more yeast

Hi all, 

In regard to yeast  "reproducing"; yeast reproduce sexually and asexually.  I could go in to all the details but suffice it to say that they won't reproduce sexually under anaerobic conditions, they are quite happy to bud however (asexual reproduction) and grow only somewhat slower under these conditions.  Believe me, this is what I do for a living.  The research lab I work in studies mitochondria and we have many yeast strains (Saccharomyces cerevisiae) that completely lack mitochondria, yet we are able to maintain them indefinately. THey will even mate, but not sporulate. 

Secondly, I should clarify that the reason you don't want the sludge on the very bottom is that it contains deep stationary phase cells that will take longer to begin growing again.  Actually the layer of cells on the top of the bottom sludge is best if you don't have yeast that "float" in the medium very well.   
What I do is swirl my flask just a bit to get the loose cells suspended, then I set aside about 1/2 cup of this and dump the rest.  you dont want to be keeping too many old cells IMO. eventually they will die. besides the cultures get nasty. 

Also  I  affirm that bakers yeast are not related to any disease froming or tissue culture contaminating fungi. 

I am a big fan of the yeast method of CO2 and would be happy to trade anyone some of my super yeast for cuttings. =)
I also have great recipe for yeast media that you can make at home without lab grade chemicals. 

Thanks for the opportunity to share my essoteric knowledge. 
in Dallas