DISRUPTION OF THE YEAST ATH1 GENE CONFERS BETTER SURVIVAL AFTER DEHYDRATION, FREEZING, AND ETHANOL SHOCK - POTENTIAL COMMERCIAL APPLICATIONS

The accumulation of trehalose is a critical determinant of stress resi stance in the yeast Saccharomyces cerevisiae. We have constructed a ye ast strain in which the activity of the trehalose-hydrolyzing enzyme, acid trehalase (ATH), has been abolished. Loss of ATH activity was acc omplished by disrupting the ATH1 gene, which is essential for ATH acti vity. The Delta ath1 strain accumulated greater levels of cellular tre halose and grew to a higher cell density than the isogenic wild-type s train, In addition, the elevated levels of trehalose in the Delta ath1 strain correlated with increased tolerance to dehydration, freezing, and toxic levels of ethanol. The improved resistance to stress conditi ons exhibited by the Delta ath1 strain may make this strain useful in commercial applications, including baking and brewing.