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

[摘要] Screening for new sake yeasts can expand the sensory diversity of sake, due to their production ofmetabolites that characterize sake’s aroma andtaste. In this study, mud from tidal flats in the AriakeSea was screened for Saccharomyces cerevisiaestrains with ethanol productivity suitable for sakebrewing, and the brewing characteristics of isolatedstrains were evaluated. Five strains (H1-1, H1-2,H1-3, H3-1, and H3-2) classified as S. cerevisiae wereisolated. Karyotype analysis by pulsed-field gel electrophoresis showed that five isolated strains wereclosely related to sake yeast strains (K7, K701, K9,K901, and Y52) instead of laboratory yeast strain.Results of small-scale brewing tests including sakeyeast strains K701, K901, and Y52 showed that thefive isolated strains have fermentation activity comparable to sake yeast strains. Principal componentanalysis (PCA) revealed that the five isolated strainsproduce higher levels of ethyl caproate and lowerlevels of acidic compounds than sake yeasts. In addition, isolated strains H3-1 and H3-2 produce higherlevels of isoamyl acetate and lower levels of aceticacid than other isolated strains. Consequently, fiveS. cerevisiae strains that have high fermentationactivity and differ from common sake yeast strainsin terms of brewing characteristics were successfullyisolated from the Ariake Sea.

[学科分类] 微生物学和免疫学

[关键词] Ariake sea;Brewing characteristics;Isolation;Saccharomyces cerevisiae;Sake;Sakeyeast