【目的】酿酒酵母是白酒发酵的主要微生物,对白酒的产量及质量都有重要影响。而酱香酒酿造环境具有高温、酸性、高乙醇等胁迫因素,研究其中酿酒酵母的生理代谢特征并有目的地应用于白酒实际生产中。【方法】从酱香酒酿造环境中筛选一株性能优良的酿酒酵母菌株,比较其与酿酒酵母模式菌株S288c和商业酵母的生理代谢特征。【结果】从酱香型酒醅中筛选得到性能优良的Saccharomyces cerevisiae MT1,该菌株可耐受高温42°C,高浓度乙醇(16%,体积比),低p H(2.0),其最大比生长速率和最大比产乙醇速率分别达到了S288c的125%和114%,其乙醇转化率也要高于其他菌株。一些挥发性物质只有在MT1的发酵液中可检测到,包括苯并噻唑、2,3-二氢苯并呋喃、4-乙烯基愈创木酚以及丁羟甲苯等,MT1的苯乙醇、法尼醇、橙花叔醇、乙偶姻和大马酮量也要高于S288c。另外,MT1可以利用多种碳源发酵产乙醇,如半乳糖、麦芽糖、蜜二糖、松二糖、海藻糖和棉子糖等。【结论】来源于酱香酒酿造的S.cerevisiae MT1具有高耐受力、高效的发酵性能及更广泛的碳源利用图谱,并能生成多种挥发性物质。
[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(p H 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 S288 c, 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 S288 c and other strains, MT1 has the higher environmental stress tolerance, more efficient fermentation performance and wider range of carbon source utilization.