Fig. 3

Alcohol tolerance and production of WT, Cz30 and Cz5. a The survival assay. The colonies of WT and Cz30 were exposed to 0%, 4%, 8% and 12% ethanol concentrations. b The growth assay. The cell densities of WT and Cz30 strains treated with different ethanol concentrations were measured at 36 h. Cz30 showed better growth than WT at 2%, 4% and 6% ethanol concentrations. c Cell growth and ethanol production of WT and Cz30 strains. The left y axis represents the cells density, the right y axis represents the ethanol production, and the x axis represents the time. Cz30 showed a higher ethanol production than WT. d–f WT, Cz5, and Cz30 were exposed to 4%, 6%, and 8% ethanol for 48 h in growth assay. Cz30 exhibited higher tolerance than Cz5 and WT at 4% and 6% ethanol. Cz5 exhibited better tolerance than WT at 4%, but not at 6%. WT, Cz5, and Cz30 did not grow at 8% ethanol at the initial cell density of 1.0 OD_600nm. The data represent the mean ± SD (n = 3)