乙醇与酸度协同作用推动芝麻香型白酒固态发酵过程的微生物群落演替

Synergism between ethanol and acidity drives microbial community succession during roasted sesame-flavor liquor solid-state fermentation

摘要:

【背景】揭示白酒固态发酵过程中微生物组装规律及其环境驱动因素，对于解析白酒酿造微生物特征具有重要作用。【目的】揭示芝麻香型白酒固态发酵过程中微生物群落的演变规律及其演替的环境推动力。【方法】通过高通量测序揭示固态发酵过程中的优势微生物及群落结构演变过程；通过PICRUSt预测固态发酵过程中原核微生物群落代谢途径分布变化；通过关联分析揭示酒醅理化因子对微生物群落结构演变的解释率；通过实验室模拟发酵验证理化因子对群落组成的影响。【结果】芝麻香型白酒固态发酵过程包括2个阶段：阶段I (0?5 d)，乙醇合成速率和还原糖消耗速率最高，Bacillus和Pichia是丰度最高的微生物属，酸度是群落演替最关键推动力；阶段II (5?30 d)，Lactobacilus和Saccharomyces是丰度最高的微生物属，乙醇是群落演替最关键推动力。在固态发酵过程中酒醅理化因子对群落演替的解释率为68.27%，其中乙醇(最高解释变量)和酸度的解释率分别为13.76%和4.43%，二者的共同解释率为23.17%，对推动微生物群落演替具有协同作用。【结论】揭示了芝麻香型白酒固态发酵过程的微生物群落演变规律及其演替的环境推动力，为提高白酒固态发酵过程可控性提供依据。

Abstract:

[Background] The assembly dynamics of microbial community and its environmental driving forces during liquor solid-state fermentation (SSF) is important for revealing the characteristics of brewing microbes. [Objective] The purpose of this study was to reveal microbial community succession and its environmental driving forces during roasted sesame-flavor liquor SSF. [Methods] The dominant genera and community structure transition were revealed by high-throughput sequencing. The distribution of metabolic pathways in prokaryotic microbial community during SSF was predicted by PICRUSt. The interpretation rate of physicochemical properties to microbial community composition was revealed by correlation analysis. The effect of physicochemical properties on community composition was verified by simulating fermentation under laboratory conditions. [Results] The roasted sesame-flavor liquor SSF process was divided into two stages: At stage I (0?5 d), ethanol and acidity reached the highest synthesis rate and consumption rate while Bacillus and Pichia were the most abundant prokaryotic/eukaryotic genus. Acidity was the key environmental driving force. At stage II (5?30 d), Lactobacillus and Saccharomyces were of highest abundance and ethanol was the key environmental driving force. The interpretation rate of physicochemical properties for microbe’s distribution during SSF was 68.27%. Ethanol and acidity accounted for 13.76% and 4.43% respectively while the combination of ethanol and acidity accounted for 23.17% and had significant synergism on driving community succession. [Conclusion] The study revealed microbial community succession and its environmental driving force, which could help to control the liquor SSF processes effectively.