ACCUMULATION AND ROLE OF TREHALOSE IN TORULASPORA-DELBRUECKII NO-3110

We isolated an alcohol-fermenting yeast, Torulaspora delbrueckii No. 3110, which was more salt-tolerant than Saccharomyces cerevisiae IFO 0224 as measured by alcohol fermentation, Strain No. 3110 produced 5.5 wt% of ethanol in a medium containing 1 M NaCl in 4 days, but strain IFO 0224 produced a mere 0.8%. Strain No. 3110 constitutively accumulated intracellular trehalose (10-17% of dry cell weight). A mutant, T1, did not accumulate trehalose, T1 synthesized and assimilated less trehalose and was less salt-tolerant than No, 3110, These results suggest that metabolism of trehalose is important for the expression of salt tolerance.