构建ADH2和THI3基因敲除酿酒酵母用于降低糯米酒中高级醇的研究

为了降低糯米酒高级醇含量，以酿酒酵母（Saccharomyces cerevisiae）菌株XF1的单倍体XF1a7和XF1α6为原始菌，采用Cre/loxP同源重组系统构建乙醇脱氢酶基因ADH2和类丙酮酸脱羧酶基因THI3缺失的单倍体酵母，再通过单倍体的杂交构建ADH2单基因缺失双倍体酵母XF1-A和ADH2与THI3双基因缺失的双倍体酵母XF1-AT。结果表明，重组菌XF1-A、XF1-AT与原始菌XF1的生长性能相似，菌株XF1-A和XF1-AT的基本发酵性能与菌株XF1无显著差异，菌株XF1-A酿造糯米酒中高级醇含量为522.16 mg/L，比菌株XF1低11.16%；菌株XF1-AT的高级醇含量为462.03 mg/L，比菌株XF1低21.39%。综上，ADH2和THI3基因敲除酿酒酵母能够有效降低糯米酒中高级醇生成量。

Construction of ADH2 and THI3 gene deletion Saccharomyces cerevisiae to reduce the higher alcohols concentration in glutinous rice wine

To reduce the higher alcohol content of glutinous rice wine, using the haploid XF1a7 and XF1α6 of Saccharomyces cerevisiae strain XF1 as the original strain, haploid yeast with deletion of ethanol dehydrogenase gene ADH2 and pyruvate decarboxylase gene THI3 was constructed by Cre/loxP homologous recombination system. Then diploid yeast XF1-A with deletion of ADH2 and diploid yeast XF1-AT with deletion of THI3 gene were constructed by hybridization of haploid yeast. The results showed that the growth performance of the recombinant strain XF1-A and XF1-AT was similar to that of the original strain XF1. The basic fermentation performance of strain XF1-A and XF1-AT was not significantly different from that of strain XF1. The content of higher alcohol in strain XF1-A was 522.16 mg/L, which was 11.16% lower than that of strain XF1. The higher alcohol content of strain XF1-AT was 462.03 mg/L, which was 21.39% lower than that of strain XF1. In conclusion, ADH2 and THI3 gene knockout S. cerevisiae could effectively reduce the higher alcohol production in glutinous rice wine.