应用高通量测序技术解析清香型大曲微生物多样性

Microbial Diversity Analysis of Flight-flavor Daqu Using High-throughput Sequencing

目的:分析清香型大曲微生物整体数量、种类,确定清香型大曲优势菌,为进一步解析清香型大曲功能微生物,筛选优良酿造微生物奠定基础。方法:利用传统培养分离方法和高通量测序技术相结合,对采自北京、山西、台湾、黑龙江、河北5地的11份清香型大曲进行微生物种群多样性分析。结果:传统分离结果表明:11种清香大曲微生物总数各不相同,不同大曲中真菌数量均多于细菌数量。扣囊覆膜酵母是大曲真菌的主要组成部分,乳酸菌和芽孢杆菌分别构成不同大曲细菌的优势类群。高通量分析结果表明:11种大曲真菌多样性较为一致,扣囊覆膜酵母是优势真菌。细菌多样性则较为丰富,主要由乳酸菌、芽孢杆菌、放线菌、泛菌属、葡萄球菌5类组成。其中乳酸菌类是优势细菌,主要包括融合魏斯氏菌、戊糖片球菌、柠檬明串珠菌、耐酸乳杆菌这4个种。结论:清香型大曲微生物多样性丰富,不同大曲样品微生物总数差异较大,真菌数量远大于细菌数量。扣囊覆膜酵母、乳酸菌和芽孢杆菌为清香大曲真菌和细菌的主要组成部分。

Objective: To investigate the species diversity and composition of microorganisms in the light-flavor Daqu which is used as the fermentation starter for the production of light-flavor Baijiu (Chinese liquor), which is the prerequisite for further functional analyses of the microorganisms and for screening and selection of better stains. Methods: Eleven samples of light-flavor Daqu collected from five different regions (Beijing, Shanxi, Taiwan, Heilongjiang and Hebei) were collected and subjected to microbial diversity analyses using traditional culture-dependent method and high-throughput rRNA gene (rDNA) library sequencing technology. Results: The results obtained from the culture-dependent method indicated that the total numbers of microorganisms from the 11 samples were different, the number of fungi in all Daqu samples was more than that of bacteria. The dominant fungus in all the Daqu samples was Saccharomycopsis fibuligera, and the dominant bacteria were Lactobacillus and Bacillus species. The composition of fungi in the 11 samples were comparatively consistent based on the result of high-throughput sequencing, and S. fibuligera was the major fungus. The diversity of bacteria was higher but the composition varied significantly in different samples. The bacteria mainly belonged to five group: lactic acid bacteria, Bacillus, Actinomycetes, Pantoea and Staphylococcus. Lactic acid bacteria were dominant, including four species: Weissella confuse, Pediococcus pentosaceus, Leuconostoc citreum and Lactobacillus acetotolerans. Conclusion: Microbial diversity of light-flavor Daqu is rich, the total number of microorganisms from different Daqu samples is obviously different, the number of fungi is greater than that of bacteria. S. fibuligera, lactic acid bacteria and Bacillus and are the major components of fungi and bacteria respectively in light-flavor Daqu.