title: Screening and construction of Saccharomyces cerevisiae strains with improved multi-tolerance and bioethanol fermentation performance.
abstract: In this study, a systemic analysis was initially performed to investigate the relationship between fermentation-related stress tolerances and ethanol yield. Based on the results obtained, two elite Saccharomyces cerevisiae strains, Z8 and Z15, with variant phenotypes were chosen to construct strains with improved multi-stress tolerance by genome shuffling in combination with optimized initial selection. After three rounds of genome shuffling, a shuffled strain, YZ1, which surpasses its parent strains in osmotic, heat, and acid tolerances, was obtained. Ethanol yields of YZ1 were 3.11%, 10.31%, and 10.55% higher than those of its parent strains under regular, increased heat, and high gravity fermentation conditions, respectively. YZ1 was applied to bioethanol production at an industrial scale. Results demonstrated that the variant phenotypes from available yeast strains could be used as parent stock for yeast breeding and that the genome shuffling approach is sufficiently powerful in combining suitable phenotypes in a single strain.
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang Province, PR China.
authors.forename: Dao-Qiong
authors.initials: DQ
authors.lastname: Zheng
authors.forename: Xue-Chang
authors.initials: XC
authors.lastname: Wu
authors.forename: Xiang-Lin
authors.initials: XL
authors.lastname: Tao
authors.forename: Pin-Mei
authors.initials: PM
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.forename: Xiao-Qin
authors.initials: XQ
authors.lastname: Chi
authors.forename: Yu-Dong
authors.initials: YD
authors.lastname: Li
authors.forename: Qing-Feng
authors.initials: QF
authors.lastname: Yan
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Zhao
mesh_terms: D056804:Biofuels / Q000382:microbiology*; D000431:Ethanol / Q000378:metabolism*; D024861:Genetic Enhancement / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000145:classification* / Q000502:physiology*; D013045:Species Specificity; D013312:Stress, Physiological / Q000502:physiology*
chemical_list: D056804:Biofuels; D000431:Ethanol