Abstract：
Chromosome aneuploidy is a common phenomenon in industrial yeast. Aneuploidy is considered one of the strategies to enhance the industrial properties of Saccharomyces cerevisiae strains. However, the effects of chromosomal aneuploidy on the brewing properties of sake have not been extensively studied. In this study, sake brewing was performed using a series of genome-wide segmental duplicated laboratory S. cerevisiae strains, and the effects of each segmentally duplicated region on sake brewing were investigated. We found that the duplication of specific chromosomal regions affected the production of organic acids and aromatic compounds in sake brewing. As organic acids significantly influence the taste of sake, we focused on the segmental duplication of chromosome II that alters malate levels. Sake yeast Kyokai No. 901 strains with segmental chromosome II duplication were constructed using a polymerase chain reaction-mediated chromosomal duplication method, and sake was brewed using the resultant aneuploid sake yeast strains. The results showed the possibility of developing sake yeast strains exhibiting low malate production without affecting ethanol production capacity. Our study revealed that aneuploidy in yeast alters the brewing properties; in particular, the aneuploidy of chromosome II alters malate production in sake brewing. In conclusion, aneuploidization can be a novel and useful tool to breed sake yeast strains with improved traits, possessing industrial significance.
摘要：
染色体非整倍性是工业酵母中的常见现象。非整倍体被认为是增强酿酒酵母菌株工业特性的策略之一。然而,染色体非整倍性对清酒酿造特性的影响尚未得到广泛研究。在这项研究中,清酒酿造是使用一系列全基因组片段复制的实验室酿酒酵母菌株进行的，并研究了每个分段重复区域对清酒酿造的影响。我们发现，特定染色体区域的重复会影响清酒酿造中有机酸和芳香族化合物的产生。由于有机酸会显着影响清酒的味道，我们专注于改变苹果酸水平的II号染色体的分段复制。清酒酵母KyokaiNo.采用聚合酶链反应介导的染色体复制方法,构建了901株染色体Ⅱ段重复的菌株,并使用所得的非整倍体清酒酵母菌株酿造清酒。结果表明，在不影响乙醇生产能力的情况下，可以开发出苹果酸产量低的清酒酵母菌株。我们的研究表明，酵母的非整倍性改变了酿造特性；特别是，II号染色体的非整倍性改变了清酒酿造中苹果酸的产生。总之,非整倍化可以是一种新颖而有用的工具来培育具有改善性状的清酒酵母菌株，具有工业意义。
