Isolation of a malic acid-overproducing sake yeast that does not possess the known mutations causing high-malic acid-production.

Malic acid is an organic acid that contributes to the refreshing taste of sake. Sake yeast strains with high-malic acid-productivity have been bred, and numerous mutations causing high-malic acid-production have been identified. Here, we spontaneously isolated a high-malic acid-producing mutant among the selected 2-deoxyglucose resistants, that does not possess the known mutations causing high-malic acid-production from the original sake yeast.