Development of sake yeast haploid set with diverse brewing properties using sake yeast strain Hiroshima no. 6 exhibiting sexual reproduction

Publication date: Available online 19 February 2020Source: Journal of Bioscience and BioengineeringAuthor(s): Risa Yamasaki, Tetsuya Goshima, Kenji Oba, Muneyoshi Kanai, Ritsushi Ohdoi, Dai Hirata, Takeshi AkaoAmong sake yeast strains, Kyokai no. 7 (K7) and its closely related strains (K7 group) are predominantly used because of their excellent brewing properties. In the sake industrial sector, the need for various types of yeast strains is high. Although crossbreeding is an effective method for generating genetic diversity that should result in diverse characteristics, most K7 group strains lack normal sporulation ability, including the ability to undergo meiotic chromosomal recombination, which leads to difficulties in crossbreeding. Accordingly, the improvement of sake yeast strains primarily depends on mutagenesis and suitable selection in a stepwise manner. Our recent study revealed that the long-preserved sake yeast strain Hiroshima no. 6 (H6) does not belong to the K7 group despite genetically being extremely similar. In addition, H6 exhibited normal sporulation. Thus, we isolated haploid cells from H6 and mated them with previously isolated haploid cells of K7 group strains. The crossbred diploid strains had normal sporulation ability; hence, we performed tetrad analysis. The brewing characteristics of the obtained haploid set were extremely diverse. Principal component analysis based on the volatile and organic acid components measured using small-scale sake brewing ...
Source: Journal of Bioscience and Bioengineering - Category: Biomedical Science Source Type: research