基于ITS4/5 rRNA区序列对不同时期大曲中霉菌的分离与鉴定

利用大曲作为糖化发酵剂是中国传统白酒主要的工艺特点之一。大曲中的微生物组成十分丰富包括各种种类的霉菌、酵母以及细菌,这些复杂的微生物体系为白酒的发酵提供了必要的微生物、酶以及风味物质。其中霉菌作为酒类发酵生产中必不可少的微生物,在大曲发酵过程中能够分泌一些糖化酶和蛋白酶等多种酶类以及有机酸等多种代谢产物,对大曲质量好坏起着重要作用。为了探究大曲中霉菌功能,本文对不同时期大曲中分离的霉菌采用ITS4/5 rRNA区序列进行分析比对,共分离鉴定了193株霉菌,分属于13个种。主要为红曲(Aspergillus ruber),米根霉(Rhizopus oryzae),微小根毛霉(Rhizomucor pusillus),Rhizopus azygosporus,烟曲霉(Aspergillus fumigatus),嗜热子囊菌(Thermomyces lanuginosus),谢瓦氏曲霉(Aspergillus salwaensis),Aspergillus chevalieri,米曲霉(Aspergillus oryzae)等,并构建了M-L系统树。根据这些分离鉴定的结果初步探究出大曲生产过程中不同时期霉菌的组成和变化规律。这些结果为进一步研究中国传统白酒的酿造微生物奠定了一定的基础。

Isolation and Identification of Mold from Daqu in Different Periods Based on the ITS4/5 rRNA Region Sequence

Daqu, the saccharifying ferments in Chinese traditional liquor fermentation, is rich in microorganisms, including various types of fungi, yeast and bacteria, providing necessary microorganisms, enzymes and flavor substances for the fermentation of liquor. The mold is a necessary microorganism in alcoholic fermentation, and can secrete some enzymes such as glucoamylase and protease and some metabolites such as organic acids , playing an important role in the quality of Daqu. In order to explore the function of mold in Daqu, 193 strains of fungi were isolated from Daqu in different fermentation periods. Analyzsis and by ITS4/5 rRNA sequence. showed that those strains can be identified to 13 species and the main strains included Aspergillus ruber, Rhizopus oryzae, Rhizomucor pusillus, Rhizopus azygosporus, Aspergillus fumigatus, Thermomyces lanuginosus, Aspergillus salwaensis, Aspergillus chevalieri, Aspergillus oryzae and so on. The construction of the M-L tree was established and the composition and variation patterns of mold in different stages of Daqu production were also explored. These results provided a foundation for further research on the brewing microorganisms of Chinese traditional liquor.