Taxonomic Study on Yeasts Isolated from Awamori Distilleries without Inoculation of Pure Yeast Culture such as Awamori No.1

Characteristics of Awamori Yeasts (Part 5)

Abstract

Seventy-nine strains of Saccharomyces cerevisiae were isolated from awamori distilleries without inoculation of pure yeast culture such as Awamori No.1.
Nine strains were isolated from rice koji of awamori. Thirty strains were isolated from rice koji of awamori by an enrichment culture method. Thirty strains were isolated from awamori mashes. Ten strains were isolated by the enrichment culture method from soil in awamori distilleries.
The isolated strains required both pantothenate and thiamine in omission of citric acid and potassium-citrate from the medium used ammonium sulphate as the sole nitrogen source, showing being not able to grow in the vitamin-free media used ammonium sulphate as the nitrogen source. However, they could grow in the vitamin-free medium containing citric acid and potassium·citrate with ammonium sulphate as the nitrogen source and thiamine. They have the froth forming ability in sake mashes, and could not grow in the medium containing yeastcidin.
These were the same characters remarked in awamori yeasts isolated in 1980.