巨峰葡萄自然发酵不同阶段酵母菌的组成及差异分析

采集巨峰葡萄发酵不同阶段的发酵液,通过酵母菌的分离、纯化、WL培养基的鉴别培养、表型性状的聚类分析以及显微细胞形态观察,对酵母菌进行初步的表型分群,挑选不同表型群的代表菌株进行DNA的提取以及26S rDNA D1/D2基因扩增和测序分析。共得到64株酵母菌,经过对获得酵母菌菌株的表型鉴定得到14个表型群,通过26S rDNA基因测序、比对,酵母菌最终鉴定为3个不同的酵母菌种群,分别为假丝酵母、路氏类酵母和酿酒酵母。其中发酵前期包含的酵母菌种群是假丝酵母(64%)和路氏类酵母(36%);发酵中期包含假丝酵母(10%)、路氏类酵母(5%)和酿酒酵母(85%);发酵后期则包含路氏类酵母(43%)和酿酒酵母(57%)。结果表明,发酵不同阶段的优势酵母菌种群是存在差异的,酿酒酵母在发酵的中后期均占优势,假丝酵母仅在发酵的前中期存在且只在前期占优势,路氏类酵母在发酵的各个时期均有发现,但发酵后期占比最高。

Analysis of composition and difference of yeast populations in different stages of natural fermentation of Kyoho grape

Samples of Kyoho wine were collected at different stages of the fermentation,and then yeast populations were isolated,purified,and WL were cultured,and the phenotypic taxonomy was performed.In addition,the representatives were taken for DNA extraction and 26S rRNA gene amplification and sequencing analysis.A total of 64 strains of yeast were obtained and then were taken for phenotyping and 14 phenotypic groups were found.While through 26S rRNA gene sequencing and phylogenetic analysis,they were identified as three different known yeast species,Candida humilis,Saccharomycodes ludwigii and Saccharomyces cerevisiae.In the early stage of the fermentation,two kinds of yeast species were included,Candida humilis (64％) and Saccharomycodes ludwigii (36％);while in the middle stage,all of the three species were involed,Candida humilis (10％),Saccharomycodes ludwigii (5％) and Saccharomyces cerevisiae (85％);in addition,at the late stage,only Saccharomycodes ludwigii (43 ％) and Saccharomyces cerevisiae (57 ％) were found.The results showed that the dominant yeast species from different fermentation stages were different,and Saccharomyces cerevisiae were the dominant species in both of the middle and late stages of the fermentation,however Candida humilis was found in both the early and middle fermentation stages but was dominant only in the early stage.Saccharomycodes ludwigii was found in all of the three stages of the fermentation and was dominant only in the late stage.