Improvement of the multiple-stress tolerance of an ethanologenic Saccharomyces cerevisiae strain by freeze-thaw treatment.
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).
Wei
Pingying
P
Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100080, P.R. China.
Li
Zilong
Z
Lin
Yuping
Y
He
Peng
P
Jiang
Ning
N
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
D000431:Ethanol; D014199:Trehalose; D006861:Hydrogen Peroxide; D005947:Glucose; D019342:Acetic Acid