Specific physiological characteristic of Saccharomyces cerevisiae in Chinese Maotai-flavor liquor making

Abstract:

[Objective] Saccharomyces cerevisiae is the predominant microbe in Maotai-flavor liquor producing which has several stressors. Learning its physiological characteristic would provide an insight in improving the yield and quality of liquor. [Methods] One S. cerevisiae strain with excellent performance was selected from the fermented grains of Maotai-flavor liquor making. Then the physiological characteristics of this strain were compared with other S. cerevisiae strains. [Results] One strain named as S. cerevisiae MT1 with excellent performance was selected from the fermented grains in Maotai-flavor liquor making. MT1 could tolerate high temperature (42 °C), high concentration of ethanol (16%, V/V) and strong acid environment (pH 2.0). The maximum specific growth rate and the maximum ethanol production rate of MT1 were as high as 125% and 114% of those of S288c, respectively. Its ethanol conversion rate was also higher than other strains. Several volatile compounds only can be detected in fermentation liquor of MT1. MT1 could also yield more phenethyl alcohol, farnesol, nerolidol, beta damascene and acetoin. In addition, MT1 could utilize and ferment a variety of carbon source to produce ethanol. [Conclusion] Compared with the model strain S288c and other strains, MT1 has the higher environmental stress tolerance, more efficient fermentation performance and wider range of carbon source utilization.