title: Genomic reconstruction to improve bioethanol and ergosterol production of industrial yeast Saccharomyces cerevisiae.
abstract: Baker's yeast (Saccharomyces cerevisiae) is the common yeast used in the fields of bread making, brewing, and bioethanol production. Growth rate, stress tolerance, ethanol titer, and byproducts yields are some of the most important agronomic traits of S. cerevisiae for industrial applications. Here, we developed a novel method of constructing S. cerevisiae strains for co-producing bioethanol and ergosterol. The genome of an industrial S. cerevisiae strain, ZTW1, was first reconstructed through treatment with an antimitotic drug followed by sporulation and hybridization. A total of 140 mutants were selected for ethanol fermentation testing, and a significant positive correlation between ergosterol content and ethanol production was observed. The highest performing mutant, ZG27, produced 7.9 % more ethanol and 43.2 % more ergosterol than ZTW1 at the end of fermentation. Chromosomal karyotyping and proteome analysis of ZG27 and ZTW1 suggested that this breeding strategy caused large-scale genome structural variations and global gene expression diversities in the mutants. Genetic manipulation further demonstrated that the altered expression activity of some genes (such as ERG1, ERG9, and ERG11) involved in ergosterol synthesis partly explained the trait improvement in ZG27.
authors.affiliation: Zhejiang University, Zijingang Campus, 866 Yuhangtang Road, Hangzhou, 310058, Zhejiang, People's Republic of China.
authors.forename: Ke
authors.initials: K
authors.lastname: Zhang
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Tong
authors.forename: Kehui
authors.initials: K
authors.lastname: Gao
authors.forename: Yanan
authors.initials: Y
authors.lastname: Di
authors.forename: Pinmei
authors.initials: P
authors.lastname: Wang
authors.forename: Chunfang
authors.initials: C
authors.lastname: Zhang
authors.forename: Xuechang
authors.initials: X
authors.lastname: Wu
authors.forename: Daoqiong
authors.initials: D
authors.lastname: Zheng
mesh_terms: D004875:Ergosterol / Q000096:biosynthesis*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005818:Genetic Engineering; D014644:Genetic Variation; D007218:Industrial Microbiology; D010641:Phenotype; D040901:Proteomics; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D000431:Ethanol; D004875:Ergosterol