Development of sake yeast breeding and analysis of genes related to its various phenotypes

Abstract

Sake is a traditional Japanese alcoholic beverage made from rice and water, fermented by the filamentous fungi Aspergillus oryzae and the yeast Saccharomyces cerevisiae. Yeast strains, also called sake yeasts, with high alcohol yield and the ability to produce desired flavor compounds in the sake, have been isolated from the environment for more than a century. Furthermore, numerous methods to breed sake yeasts without genetic modification have been developed. The objectives of breeding include increasing the efficiency of production, improving the aroma and taste, enhancing safety, imparting functional properties, and altering the appearance of sake. With the recent development of molecular biology, the suitable sake brewing characteristics in sake yeasts, and the causes of acquisition of additional phenotypes in bred yeasts have been elucidated genetically. This mini-review summarizes the history and lineage of sake yeasts, their genetic characteristics, the major breeding methods used, and molecular biological analysis of the acquired strains. The data in this review on the metabolic mechanisms of sake yeasts and their genetic profiles will enable the development of future strains with superior phenotypes.

Effect of kuratsuki Bacillus and Priestia on Taste of Sake

“…The sake yeast strains AK25, K901, K1401, and K1801, which are used in Japanese sake breweries [56][57][58], and kuratsuki bacterial strains A-10 and B-12 [21] were used in this study. Each strain was grown in TGY medium (5 g/L tryptone, 1 g/L glucose, and 3 g/L yeast extract) at 25 • C for 12 h prior to cultivation.…”

Application of unimodal probability distribution models for morphological phenotyping of budding yeast

“…Budding yeast has been used not only for basic research in genetics, biochemistry, cell biology, pharmacology, evolutionary biology, biochemistry, and systems biology but also in applied research such as microbial fermentation and biotechnology. S. cerevisiae consists of wild subspecies observed in nature and domesticated subspecies used for the production of food (Sun et al 2022 ) and alcoholic beverages, such as wine (Borneman et al 2016 ), beer (Gallone et al 2016 ), and sake (Negoro and Ishida 2022 ). Although domesticated yeasts have been extensively studied using comparative genomics (Peter et al 2018 ), their morphological analysis also yielded important insights for breeding.…”

Carbon stable isotopes of glucose during the degradation of rice by the koji fungus Aspergillus oryzae

“…During koji production, A. oryzae grows on steamed rice ( Oryaze sativa ) and secretes hydrolytic enzymes, including α-amylase and glucoamylase, that degrade starch into fermentable sugars [ 6 , 7 ]. This process is essential for generating the glucose required for making numerous traditional Japanese fermented foods, such as sake [ 8 , 9 ], sparkling sake [ 10 ], amazake [ 11 , 12 ], shochu [ 13 ], vinegar [ 14 ], mirin [ 15 , 16 ], miso [ 17 , 18 ], and shoyu [ [19] , [20] , [21] ]. The saccharification of rice starch into glucose is critical in sake production, as this sugar is the primary carbon source for sake yeast ( Saccharomyces cerevisiae ), which converts the glucose into ethanol via alcoholic fermentation [ 22 , 23 ].…”