The so-called Kyokai yeasts have been cultivated and supplied to most of the sake breweries in Japan by Nippon JOzOkyokai, since 1906. They are discriminated each other by Kyokai numbers and recognized by glucose-TTC-staining as showing all red colonies. The authors, however, found that when maltose, α-methyl-D-glucoside (α-MG), or galactose were used as carbon source in place of glucose, they showed colonies of mixture of red and pink and, sometimes, of only pink or white depending on the year of cultivation and/or the kind of yeast, as shown in Tables 1-3.
Among the various Kyokai yeasts cultivated since 1961, those showing colonies of singlecolor on three carbohydrate-media were selected as the representative strains as seen in Table 4. The Kyokai yeast shown by a certain number was considered to belong to a group of assigned that number, because they showed each special behaviour in sakebrewing by their number, independed from the color difference by TTC-staining.
