Yeast...Long-Term Storage

Derek Law dlaw at
Fri Oct 6 02:33:29 EST 2000

Antani <lab2NOSPAM at> wrote in message
news:xUZXHuhLAHA.120 at
> Hi there!
> Maybe this is a stupid question but....someone could tell me what is the
> best way for have long-term storage yeast stocks ?
> I've found discordant answers to it....
> Thanks a lot
> Max
 Freezing of cultures is the best long term bet, -80C is better than -20C.
Some books recomend suspending yeasts in water and storage at room
temperature. They do survive for several years like that , but sometimes
their properties change. In a former job I stored a range of yeasts
resistant to several antifungal antibiotics. When I got them from the water
cultures 6 months later they grew fine but had reverted to being sensitive
to the antibiotics. Presumably without the selective pressure they had
reverted back to a susceptible phenotype. We later reverted to freezing
cultures and never noticed any changes in antibiotic resistance in  frozen
stored cultures.

So if you want to maintain the yeast's phenotype  FREEZE!!

Derek Law



More information about the Microbio mailing list