title: Drug resistance marker-aided genome shuffling to improve acetic acid tolerance in Saccharomyces cerevisiae.
abstract: Acetic acid existing in a culture medium is one of the most limiting constraints in yeast growth and viability during ethanol fermentation. To improve acetic acid tolerance in Saccharomyces cerevisiae strains, a drug resistance marker-aided genome shuffling approach with higher screen efficiency of shuffled mutants was developed in this work. Through two rounds of genome shuffling of ultraviolet mutants derived from the original strain 308, we obtained a shuffled strain YZ2, which shows significantly faster growth and higher cell viability under acetic acid stress. Ethanol production of YZ2 (within 60 h) was 21.6% higher than that of 308 when 0.5% (v/v) acetic acid was added to fermentation medium. Membrane integrity, higher in vivo activity of the H+-ATPase, and lower oxidative damage after acetic acid treatment are the possible reasons for the acetic acid-tolerance phenotype of YZ2. These results indicated that this novel genome shuffling approach is powerful to rapidly improve the complex traits of industrial yeast strains.
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058 Zhejiang, People's Republic of China.
authors.forename: Dao-Qiong
authors.initials: DQ
authors.lastname: Zheng
authors.forename: Xue-Chang
authors.initials: XC
authors.lastname: Wu
authors.forename: Pin-Mei
authors.initials: PM
authors.lastname: Wang
authors.forename: Xiao-Qin
authors.initials: XQ
authors.lastname: Chi
authors.forename: Xiang-Lin
authors.initials: XL
authors.lastname: Tao
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.forename: Xin-Hang
authors.initials: XH
authors.lastname: Jiang
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Zhao
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology*; D003470:Culture Media / Q000378:metabolism; D032621:DNA Shuffling / Q000379:methods; D025141:Drug Resistance, Fungal / Q000235:genetics; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005819:Genetic Markers; D016681:Genome, Fungal; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D050296:Microbial Viability; D017382:Reactive Oxygen Species / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D014170:Transformation, Genetic
chemical_list: D003470:Culture Media; D005819:Genetic Markers; D017382:Reactive Oxygen Species; D000431:Ethanol; D019342:Acetic Acid