耐高温高产酒精酵母的筛选及其大曲生产应用研究

Screening of Thermotolerant Yeast Strains with High-Yield of Alcohol and Its Application in Daqu Production

以凤型大曲为菌种来源,采用三级筛方法分离筛选耐高温高产酒精酵母,并对混合菌种模拟固态发酵结果进行比较分析,将最优组合应用于大曲实际生产。结果表明:(1)三级筛选后共优选出6株目的菌株,其中耐44℃的酵母菌2株,为Y3和Y22,耐42℃的酵母菌4株,为Y7、Y10、Y13及Y14;(2)不同菌株混合固态发酵均能有效提高酒醅酒精度含量,其中6株菌混合发酵时,酒醅酒精度可达5.85%vol,较对照提高31.4%;(3)6株菌应用于大曲生产,出房曲糖化力、液化力、发酵力、酯化力分别提升了14.9%、13.1%、14.2%和5.1%。总体来看,试验筛选获得的6株菌混合使用能够有效提升大曲的综合性能,具有较好的应用前景。

Fengxiang Daqu was used as the strain source and three-step screening process was adopted for the screening of thermotolerant strains with high-yield of alcohol. Then the simulated solid-state fermentation results of mixed strains were compared and the best strain combination was used in Daqu production. The results showed that,(1) six target strains were obtained, of which 2 strains(Y3 and Y22) were resistant to 44 °C, 4 strains(Y7,Y10,Y13 and Y14) were resistant to 42 °C;(2) all mixed combinations of strains could effectively improve the ethanol content of fermented grains;as the 6 strains were mixed, the alcohol content could reach up to5.85 %vol, increasing by 31.4 % compared with the control;(3) the use of the 6 strains in Daqu production could improve the saccharifying power, liquefying power, fermenting power and esterifying power of Daqu by 14.9 %, 13.1 %, 14.2 % and 5.1 % respectively. In general, the mixed use of the 6 strains could practically improve the comprehensive performance of Daqu, which had a good application prospect.