【摘要】 该研究以伊力特浓香型大曲为筛选原料，采用传统培养分离法及产乙醇性能分析从中分离筛选优良酵母菌，并通过形态学观察及分子生物学技术对其进行菌种鉴定。利用筛选菌株制作纯菌种麸曲，并以发酵液乙醇含量为响应值，采用单因素及响应面试验对麸曲制曲工艺进行优化。结果表明，筛选得到一株产乙醇性能优良的酵母菌LX-2，经鉴定其为扣囊复膜酵母（Saccharomycopsis fibuligera）。利用菌株LX-2制作纯种麸曲的最佳制曲条件为接种量11%，发酵温度29℃，发酵时间54 h，水分添加量55%。在此优化条件下，扣囊复膜酵母LX-2纯种麸曲中的乙醇含量为6.17%，总酯和总酸含量分别为0.223 g/L和0.078 g/L，糖化酶、液化酶活力分别为370.00 U/g和530.40 U/g，说明该酵母麸曲在具备较高产乙醇能力的同时，也具有一定的糖化酶、液化酶活力。该研究对伊力特浓香型大曲中优良酵母菌的分离筛选及其麸曲制备具有一定的参考意义。更多还原

【Abstract】 In this study, using Yilite strong-flavor(Nongxiangxing) Daqu as the screening material, the superior yeast was isolated and screened by traditional culture separation method and ethanol production performance analysis. The strains were identified by morphological observation and molecular biology technology. The pure yeast Fuqu was made by the screened strains, and using the ethanol content of fermentation liquor as the response value, the Fuqu-making process was optimized by single factor and response surface tests. The results showed that a yeast strain LX-2 with good ethanol production was screened and identified as Saccharomycopsis fibuligera. The optimal conditions for making pure Fuqu with strain LX-2 were as follows: inoculum 11%, fermentation temperature 29 ℃ and time 54 h, and water addition 55%. Under these optimal conditions, the ethanol yield of yeast LX-2 was 6.17%, the total ester and total acid contents were 0.223 g/L and 0.078 g/L, respectively. The activities of saccharifying enzyme and liquefaction enzyme were 370.00 U/g and 530.40 U/g, respectively, indicating that the yeast Fuqu had the ability to produce ethanol, but also had certain activities of saccharifying enzyme and liquefaction enzyme. This study had certain reference significance for the isolation and screening of superior yeast in Yilite strong-flavor Daqu and the preparation of Fuqu.更多还原