Isolation of sake yeast strains from Ariake Sea tidal flats and evaluation of their brewing characteristics

• Published in: Journal of general and applied microbiology Vol. 68; no. 1; pp. 30 - 37
• Main Authors: Baba, Shuichiro, Sawada, Kazutaka, Orita, Ryo, Kimura, Kei, Goto, Masatoshi, Kobayashi, Genta
• Format: Journal Article
• Language: English
• Published: Japan Applied Microbiology, Molecular and Cellular Biosciences Research Foundation 01.01.2022; Japan Science and Technology Agency
• Subjects: Acetic acid; Ariake sea; Aroma; Breweries; Brewing; Brewing characteristics; Electrophoresis; Ethanol; Ethyl hexanoate; Evaluation; Fermentation; Gel electrophoresis; Isoamyl acetate; Isolation; Karyotypes; Metabolites; Principal components analysis; Pulsed-field gel electrophoresis; Saccharomyces cerevisiae; Sake; Sake yeast; Sensory evaluation; Tidal flats; Yeast; Yeasts; Ariake Sea; Isolation; Brewing characteristics; Sake yeast; Saccharomyces cerevisiae; Ariake sea; Sake
• ISSN: 0022-1260; 1349-8037
• DOI: 10.2323/jgam.2021.09.003

Screening for new sake yeasts can expand the sensory diversity of sake, due to their production of metabolites that characterize sake’s aroma and taste. In this study, mud from tidal flats in the Ariake Sea was screened for Saccharomyces cerevisiae strains with ethanol productivity suitable for sake brewing, and the brewing characteristics of isolated strains were evaluated. Five strains (H1-1, H1-2, H1-3, H3-1, and H3-2) classified as S. cerevisiae were isolated. Karyotype analysis by pulsed-field gel electrophoresis showed that five isolated strains were closely related to sake yeast strains (K7, K701, K9, K901, and Y52) instead of laboratory yeast strain. Results of small-scale brewing tests including sake yeast strains K701, K901, and Y52 showed that the five isolated strains have fermentation activity comparable to sake yeast strains. Principal component analysis (PCA) revealed that the five isolated strains produce higher levels of ethyl caproate and lower levels of acidic compounds than sake yeasts. In addition, isolated strains H3-1 and H3-2 produce higher levels of isoamyl acetate and lower levels of acetic acid than other isolated strains. Consequently, five S. cerevisiae strains that have high fermentation activity and differ from common sake yeast strains in terms of brewing characteristics were successfully isolated from the Ariake Sea.