Abstract
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.
