宋河浓香型白酒酒醅纯培养霉菌群落的组成及功能酶筛选

Composition and Functional Enzymes of the Pure-culture Mold Community from Fermented Grains of Songhe Nongxiang Liquor

摘要:

为探究宋河浓香型白酒酒醅纯培养霉菌群落组成，检测纯培养菌株与酒醅发酵过程相关的功能酶酶活特征，为白酒相关功能菌株发掘与利用提供依据，本实验采用纯培养方法，对不同发酵时间、不同位置酒醅样品中的霉菌进行分离；根据形态特征去重复后进行18S rRNA基因克隆测序，初步判断其分类地位；采用点接法进行酒醅发酵相关5种功能酶筛选。结果表明，宋河浓香型白酒酒醅中蕴含丰富霉菌类群，共获得纯培养霉菌63株，形态去重复后共计15株，归属于：草本枝孢（Cladosporium herbarum）、黑曲霉（Aspergillus niger）、沃特曼篮状菌（Talaromyces wortmannii）、嗜松篮状菌（Talaromyces pinophilus）、杂色曲霉（Aspergillus versicolor）、米曲菌（Aspergillus oryzae）、毛栓菌（Trametes hirsuta）、桔青霉（Penicillium citrinum）、菲律宾青霉（Penicillium freii）、雪白丝衣霉（Byssochlamys nivea）及两个潜在新分类单元；霉菌的纯培养检出率在宋河浓香型白酒酒醅发酵3~15 d较高，之后随发酵时间增加逐渐降低；酒醅中的纯培养霉菌菌株具有丰富的功能酶酶活特性，淀粉酶、纤维素酶、果胶酶、蛋白酶、酯化酶的酶活筛选率分别为：100%、93.3%、33.3%、73.3%、46.7%，为后续进一步研究菌株的功能及开发利用奠定基础。

Abstract:

In order to explore the community composition of pure-culture mold in the fermented grains of Songhe Nongxiang liquor, and to examine the activities of the functional enzymes related to the pure-culture fermentation process, the pure culture method was used to isolate the molds in fermented grains obtained after different fermentation times and from different positions. The 18S rRNA gene was cloned and sequenced according to the morphological characteristics (after the removal of those repeated ones) to determine preliminarily the classification status. Five kinds of functional enzymes related to fermented grains were screened by the point connection method. The results showed that the fermented grains of Songhe Nongxiang liquor were rich in molds, with totally 63 isolated strains, and 15 strains obtained after the removal of morphological repetition (which belonged to Cladosporium herbarum, Aspergillus niger, Talaromyces wortmannii, Talaromyces pinophilus, Aspergillus versicolor, Aspergillus oryzae, Trametes hirsuta, Penicillium citrinum, Penicillium freii, Byssochlamys nivea and two potentially new taxa). The detection rate of pure-culture molds in the fermented grains of Songhe Nongxiang liquor was higher from Day 3 to15 after fermentation, and then decreased gradually with the screening rates of amylase, cellulase, pectinase, protease and esterase were 100%, 93.3%, 33.3%, 73.3% and 46.7%, respectively, which lays a increase of fermentation time. The pure-culture mold strains in the fermented grains were rich in active functional enzymes, and the activity foundation for further development and utilization of the strains.