酱香型白酒第四轮次堆积发酵醅堆腰线微生物菌群多样性解析

采用纯培养和Illumina MiSeq高通量测序技术对第四轮次堆积发酵正常和腰线酒醅中的微生物菌群多样性进行解析。通过纯培养计数发现，酒醅腰线处乳酸菌、细菌以及酵母和霉菌的数量均显著高于正常酒醅（P<0.05）。经α多样性分析发现，正常和腰线部位酒醅细菌及真菌菌群的丰度和多样性差异均不显著（P>0.05）。经β多样性分析发现，两处酒醅中细菌类群差异不显著（P>0.05），而真菌类群差异显著（P<0.05）。经Wilcoxon test检验发现，酒醅腰线处芽孢杆菌（Bacillus）和丝衣霉属（Byssochlamys）的相对含量显著偏高（P<0.05），而毕赤酵母属（Pichia）、酵母属（Saccharomyces）、有孢圆酵母属（Torulaspora）和接合酵母属（Zygosaccharomyces）显著偏低（P<0.05）。相关性分析发现，腰线部位酒醅微生物菌群间相较于正常部位存在更加密切的联系。由此可见，腰线与正常部位酒醅的微生物类群差异主要体现在真菌类群上。

Microbial diversity of "waistline" fermented grains in the fourth-round stacking fermentation of sauce-flavor Baijiu

The microbial community diversity in normal and "waistline" fermented grains during the fourth-round stacking fermentation was analyzed by pure culture and Illumina MiSeq high-throughput sequencing technology, and the numbers of lactic acid bacteria, bacteria, yeasts and molds in the "waistline" fermented grains were significantly higher than those of normal fermented grains (P＜0.05). The alpha diversity analysis revealed that there was no significant difference in richness and diversity of bacterial and fungal communities in normal and "waistline" parts of fermented grains (P＞0.05). The beta diversity analysis revealed that there was no significant difference in bacterial community in the two fermented grains (P＞0.05), while the differences in fungal community in the two fermented grains were significant (P＜0.05). Wilcoxon test showed that the relative contents of Bacillus and Byssochlamys in the "waistline" fermented grains were significantly higher (P＜0.05), while that of Pichia, Saccharomyces, Torulaspora, and Zygosaccharomyces were significantly lower (P＜0.05). Correlation analysis showed that the microbial communities of fermented grains in the "waistline" were more closely correlated than those in the normal parts. In conclusion, the difference of microbial communities between the "waistline" and the normal parts of fermented grains was mainly reflected in the fungal community.