Yeast Diversity in Wine Grapes from Japanese Vineyards and Enological Traits of Indigenous Saccharomyces cerevisiae Strains

Japan has numerous vineyards with distinct geographical and climatic conditions. To the best of our knowledge, there is no comprehensive analysis of the diversity of yeasts associated with wine grapes from Japan. This study aimed to determine yeast diversity in wine grapes from four wine-producing regions in Japan and to evaluate the physicochemical characteristics of wines produced with indigenous <i>Saccharomyces cerevisiae</i> strains isolated from two regions. A total of 2648 strains were isolated from nine wine grape samples. MALDI-TOF MS and 26S rDNA sequence analyses revealed that the strains belonged to 21 non-<i>Saccharomyces</i> yeasts and 1 <i>Saccharomyces</i> yeast (<i>S. cerevisiae</i>). Non-<i>Saccharomyces</i> yeasts were found in high quantities and were highly distributed among the wine grape samples. Differences in the distribution of the identified yeast species were noted among the different wine grape varieties and regions. Indigenous <i>S. cerevisiae</i> strains of different genotypes from different regions exhibit distinct physiological traits. Our findings are expected to enhance our understanding of the local yeasts associated with Japanese vineyards and contribute to obtaining cultures that can provide region-specific organoleptic characteristics to local wines produced in Japan.