title: Improvement of the multiple-stress tolerance of an ethanologenic Saccharomyces cerevisiae strain by freeze-thaw treatment.
abstract: An effective, simple, and convenient method to improve yeast's multiple-stress tolerance, and ethanol production was developed. After an ethanologenic Saccharomyces cerevisiae strain SC521 was treated by nine cycles of freeze-thaw, a mutant FT9-11 strain with higher multiple-stress tolerance was isolated, whose viabilities under acetic acid, ethanol, freeze-thaw, H(2)O(2), and heat-shock stresses were, respectively, 23-, 26-, 10- and 7-fold more than the parent strain at an initial value 2 x 10(7) c.f.u. per ml. Ethanol production of FT9-11 was similar (91.5 g ethanol l(-1)) to SC521 at 30 degrees C with 200 g glucose l(-1), and was better than the parent strain at 37 degrees C (72.5 g ethanol l(-1)), with 300 (111 g ethanol l(-1)) or with 400 (85 g ethanol l(-1)) g glucose l(-1).
authors.affiliation: Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100080, P.R. China.
authors.forename: Pingying
authors.initials: P
authors.lastname: Wei
authors.forename: Zilong
authors.initials: Z
authors.lastname: Li
authors.forename: Yuping
authors.initials: Y
authors.lastname: Lin
authors.forename: Peng
authors.initials: P
authors.lastname: He
authors.forename: Ning
authors.initials: N
authors.lastname: Jiang
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology; D018533:Biomass; D000431:Ethanol / Q000378:metabolism* / Q000494:pharmacology; D005285:Fermentation / Q000187:drug effects; D005615:Freezing; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000494:pharmacology; D050296:Microbial Viability / Q000187:drug effects / Q000235:genetics; D009154:Mutation; D009997:Osmotic Pressure; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014199:Trehalose / Q000378:metabolism
chemical_list: D000431:Ethanol; D014199:Trehalose; D006861:Hydrogen Peroxide; D005947:Glucose; D019342:Acetic Acid