Research Institute, Gekkeikan Sake Co. Ltd., 101 Shimotoba-koyanagi-cho, Fushimi-ku, Kyoto, Japan.
Biosci Biotechnol Biochem. 2021 Apr 24;85(5):1283-1289. doi: 10.1093/bbb/zbab031.
Saccharomyces cerevisiae produces organic acids including malate during alcohol fermentation. Since malate contributes to the pleasant flavor of sake, high-malate-producing yeast strain No. 28 and No. 77 have been developed by the Brewing Society of Japan. In this study, the genes responsible for the high malate phenotype in these strains were investigated. We had previously found that the deletion of components of the glucose-induced degradation-deficient (GID) complex led to high malate production in yeast. Upon examining GID protein-coding genes in yeast strain No. 28 and No. 77, a nonsense homozygous mutation of GID4 in strain No. 28 and of GID2 in strain No. 77 were identified as the cause of high malate production. Furthermore, complementary tests of these mutations indicated that the heterozygous nonsense mutation in GID2 was recessive. In contrast, the heterozygous nonsense mutation in GID4 was considered semidominant.
酿酒酵母在酒精发酵过程中会产生包括苹果酸在内的有机酸。由于苹果酸有助于清酒的口感，因此日本酿造协会开发了高苹果酸产生酵母菌株 28 号和 77 号。在这项研究中，研究了这些菌株中导致高苹果酸表型的基因。我们之前发现，葡萄糖诱导降解缺陷 (GID) 复合物成分的缺失会导致酵母中苹果酸产量增加。在检查酵母菌株 28 号和 77 号中的 GID 蛋白编码基因时，发现 28 号菌株中的 GID4 发生无义纯合突变，77 号菌株中的 GID2 发生无义纯合突变，这是导致高苹果酸产量的原因。此外，对这些突变的互补测试表明，GID2 的杂合无义突变是隐性的。相比之下，GID4 的杂合无义突变被认为是半显性的。
