清香型白酒酿造体系中酵母菌的分离鉴定及生产特性分析

Isolation, Identification and Procuctive Traits Analysis of Yeasts in Brewing System from Light-Flavour Liquor

为解析黄鹤楼清香型白酒发酵系统中酵母种类的多样性,挖掘出功能酵母菌种,研究采用WL培养基从黄鹤楼清香型白酒大曲和酒醅中共分离筛选得到119株酵母菌,经26S rRNA D1/D2区PCR扩增测序,并结合NCBI数据库比对后可将酒醅中的酵母分为5大类型,分别为酿酒酵母、东方伊萨酵母、异常威克汉姆酵母、扣囊腹膜孢酵母和扁平云假丝酵母,其中酿酒酵母和异常威克汉姆酵母在数量上占优势。抗逆性实验结果表明,5种酵母在糖浓度不高于300.00 g/L,pH值不低于3.5,酒精度不高于12%的条件下均能够良好生长。酶活性测定结果表明,5种酵母中扣囊腹膜孢酵母糖化酶活力最高,达到1870.30 U/mL;异常威克汉姆酵母酯化酶活力最高,达到10.42 U/mL;扁平云假丝酵母糖化酶和酯化酶活力均较高,酶活分别可以达到1196.15 U/mL和6.94 U/mL;东方伊萨酵母的糖化作用弱,酶活低至200.00 U/mL,但其酯化作用却较强,酶活达至8.13 U/mL;酿酒酵母糖化和酯化作用均较弱。这些性能优良的菌株为功能强化菌的开发奠定了基础。

In order to analyze the diversity of yeast species in the fermentation system of Yellow Crane Tower light-flavour liquor and find out functional yeast strains,119 yeast strains were isolated from the Daqu and Jiupei(fermented grain) by WL medium.The D1/D2 region were sequenced by high throughput techniques and compared with NCBI database,which classfied the yeasts into five types,including Saccharomyces cerevisiae,Issatchenkia orientalis,Wickerhamomyces anomalus,Saccharomycopsis fibuligera,and Candida humilis.The results of stress tolerance experiments showed that the five kinds of yeast could grow well when the sugar concentration was not higher than 300.00 g/L,the pH was not lower than 3.5,and the alcohol content was not higher than 12%.As far as the glucoamylase and esterase activity,the detetion results showed that Saccharomycopsis fibuligera had the highest glucoamylase enzyme activity,up to 1870.30 U/mL.Wickerhamomyces anomalus had the highest esterase enzyme activity,up to 10.42 U/mL.Candida humilis exhibited higher glucoamylase and esterase activity,1196.15 U/mL and 6.94 U/mL,respectively.Issatchenkia orientalis had poor glucoamylase activity,less than 200.00 U/mL,but it has a stronger esterification ability,up to 8.13 U/mL.As for Saccharomyces cerevisiae,both glucoamylase and esterase activity were weak.These excellent strains provided the research basis on the exploitation of fuctional strains in future.