Improvement of the multiple-stress tolerance of an ethanologenic Saccharomyces cerevisiae strain by freeze-thaw treatment
2007
Wei, Pingying | Li, Zilong | Lin, Yuping | He, Peng | Jiang, Ning
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, H₂O₂, and heat-shock stresses were, respectively, 23-, 26-, 10- and 7-fold more than the parent strain at an initial value 2 x 10⁷ c.f.u. per ml. Ethanol production of FT9-11 was similar (91.5 g ethanol l-¹) to SC521 at 30°C with 200 g glucose l-¹, and was better than the parent strain at 37°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.
显示更多 [+] 显示较少 [-]