THE PRESERVATION OF YEAST CULTURES BY LYOPHILIZATION

Abstract

Evidence was obtained that brewers'' yeast cultures may undergo certain marked changes as a result of lyophilization. In several instances, the bios requirements of cultures isolated after lyophilization showed changes suggestive of a mutation or segregation of characteristics. Although all of the lyophilized cultures were found to be viable up to periods of three months, a very low survival rate (as low as 0.2%) was noted. In view of these results, it is suggested that this method of yeast preservation be viewed more critically than heretofore.