基于宏转录组学的浓香型白酒酒醅活性微生物群落空间异质性研究

Study on spatial heterogeneity of active microbial community in strong-flavor Baijiu fermented grains based on metatranscriptome

采用宏转录组学技术,对浓香型白酒酒醅中具有生理活性的细菌和真菌群落在窖池不同空间位置上的组成及差异表达基因进行研究。结果表明:细菌群落共检测到87个门、78个纲、165个目、396个科、1612个属和7234个种,真菌群落共检测到8个门、26个纲、58个目、127个科、223个属和394个种,且酒醅上、中、下层之间的活性微生物数目差异较小;各层酒醅中的细菌和真菌群落组成无明显差异,均以厚壁菌门和子囊菌门为主要优势细菌门和真菌门,以芽孢杆菌纲和酵母纲为主要优势细菌纲和真菌纲,以乳杆菌属为主要优势细菌属,以酵母菌属(上层和下层)或Scheffersomyces(中层)为主要优势真菌属;下层与中层酒醅、中层与上层酒醅之间的差异表达基因数量较多,分别为90个和67个,且主要富集在RNA降解和糖酵解/糖异生通路上,而各层酒醅之间的差异表达基因的功能大部分为代谢活动;整体上,中层酒醅中的活性微生物菌群对RNA降解的影响最低,下层酒醅中的活性微生物菌群在代谢活动上的贡献最大。

In this study,the metatranscriptome technology was used to study the differences in the composition and genes functions of the physiologically active bacterial and fungal communities in the strong-flavor Baijiu fermented grains(FGs)at different spatial locations of pit.The results showed that 87 phyla,78 classes,165 orders,396 families,1612 genera and 7234 species were detected in the bacterial community,and 8 phyla,26 classes,58 orders,127 families,223 genera and 394 species were detected in the fungal community.However,there was little difference in the number of active microorganisms among the top,middle and bottom layers of FGs.There was no significant difference in the bacterial and fungal community composition in each layer of FGs,with Firmicutes and Ascomycota as the main dominant bacterial and fungal phylum,respectively.Bacillus and Saccharomyces were the main dominant bacterial and fungal class,respectively.Lactobacillus was the main dominant bacterial genera,Saccharomyces(top and bottom)or Scheffersomyces(middle)was the main dominant fungal genera.Furthermore,the number of differentially-expressed genes between the bottom and middle layer,and between the middle and upper layer of FGs was higher and it was 90 and 67 respectively.And the differentially-expressed genes were mainly concentrated in RNA degradation and Glycolysis/Gluconeogenesis pathway,and most of the difference gene function between each layer was metabolism.The active microbial flora in the middle FGs had the lowest effect on RNA degradation,and the active microbial flora in the bottom FGs contributed the most to the metabolic activity.