Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang Province, 310058, China.
Ocean College, Zhejiang University, Zhoushan, Zhejiang Province, 316021, China.
Appl Microbiol Biotechnol. 2018 Mar;102(5):2213-2223. doi: 10.1007/s00253-017-8727-1. Epub 2018 Jan 15.
Yeast Saccharomyces cerevisiae strains isolated from different sources generally show extensive genetic and phenotypic diversity. Understanding how genomic variations influence phenotypes is important for developing strategies with improved economic traits. The diploid S. cerevisiae strain NY1308 is used for cellulosic bioethanol production. Whole genome sequencing identified an extensive amount of single nucleotide variations and small insertions/deletions in the genome of NY1308 compared with the S288c genome. Gene annotation of the assembled NY1308 genome showed that 43 unique genes are absent in the S288c genome. Phylogenetic analysis suggested most of the unique genes were obtained through horizontal gene transfer from other species. RNA-Seq revealed that some unique genes were not functional in NY1308 due to unidentified intron sequences. During bioethanol fermentation, NY1308 tends to flocculate when certain inhibitors (derived from the pretreatment of cellulosic feedstock) are present in the fermentation medium. qRT-PCR and genetic manipulation confirmed that the novel gene, NYn43, contributed to the flocculation ability of NY1308. Deletion of NYn43 resulted in a faster fermentation rate for NY1308. This work disclosed the genetic characterization of a bioethanol-producing S. cerevisiae strain and provided a useful paradigm showing how the genetic diversity of the yeast population would facilitate the personalized development of desirable traits.
从不同来源分离得到的酵母酿酒酵母菌株通常表现出广泛的遗传和表型多样性。了解基因组变异如何影响表型对于开发具有改进的经济性状的策略非常重要。用于纤维素生物乙醇生产的二倍体酿酒酵母菌株 NY1308 与 S288c 基因组相比，全基因组测序确定了基因组中存在大量的单核苷酸变异和小插入/缺失。组装的 NY1308 基因组的基因注释表明，43 个独特基因在 S288c 基因组中不存在。系统发育分析表明，大多数独特基因是通过来自其他物种的水平基因转移获得的。RNA-Seq 表明，由于未识别的内含子序列，一些独特基因在 NY1308 中没有功能。在生物乙醇发酵过程中，当发酵培养基中存在某些抑制剂（来自纤维素原料的预处理）时，NY1308 往往会絮凝。qRT-PCR 和遗传操作证实，新型基因 NYn43 有助于 NY1308 的絮凝能力。NYn43 的缺失导致 NY1308 的发酵速率更快。这项工作揭示了生产生物乙醇的酿酒酵母菌株的遗传特征，并提供了一个有用的范例，展示了酵母群体的遗传多样性如何促进所需性状的个性化开发。
