耐高温酒精酵母菌株的筛选及发酵能力比较

采用酵母菌富集培养方法和选择性培养基从中国传统大曲酒等基质中共分离得到58株具有一定的酒精发酵能力的酵母菌株。经过初筛和复筛，从中筛选获得1株能在33℃～42℃生长良好，并具有良好酒精发酵性能的酵母菌株XG-1，经分类鉴定为酿酒酵母菌（Saccharomyces cerevisiae）。40℃液体摇瓶培养条件下，XG-1菌株活菌数占总菌数的比率较安琪耐高温酿酒高活性干酵母（TRADY）高15％。将其与TRADY菌株进行木薯酒精发酵比较，33R2条件下两者的酒精发酵能力相当，但在42℃时进行酒精发酵，XG-1菌株的酒精度比TRADY菌株高20％。

Screening of thermotolerant alcohol-producing yeast and comparison of fermentation activity

In this study, 58 alcohol-producing yeast strains were isolated from various materials (e.g. China traditional Daqu liquor) using enrichment culture method and selective medium. After primary and secondary screening, a yeast strain (named XG-1) was selected from these strains, which grew well at 33-42℃ with good alcohol fermentation profiles. According to taxonomic identification, the XG-1 strain was identified as Saccharomyces cerevisiae. With liquid culture at 40℃ in shake flask,the ratio of viable count to total count of XG-1 was 15% higher than that of Angel temperature resistant alcohol instant active dry yeast (TRADY). Subsequently, the cassava fermentation activity of the XG-1 strain was measured using TRADY as a control. The XG-1 strain had similar cassava fermentation activity with the control strain at 33℃. The alcohol yield of XG-1 was 20% higher than that of TRADY at 42℃.