Microbiome diversity and evolution in stacking fermentation during different rounds of Jiang-flavoured Baijiu brewing

Microbiome during stacking fermentation is one of the most important factors in Jiang-flavoured (Moutai - flavour) Baijiu brewing, as it determines the yield and quality. Here, high-throughput sequencing and statistical analysis were performed to analyse the diversity and succession of microbial communities during stacking fermentation for seven rounds. In total, 27 bacterial phyla and 658 genera and seven fungal phyla and 156 genera were identified in 26 composite samples obtained from 130 individual samples. Although the microbial communities were rich and varied in the seven rounds, several genera were highly stable, including core bacterial genera, i.e., Bacillus (13.32%–31.98%), Lentibacillus (1.08%–28.79%), Kroppenstedtia (0.68%–24.02%), Oceanobacillus (0.11%–11.04%), and Lactobacillus (0.43%–26.41%) and core fungal genera, i.e., Thermomyces (9.48%–53.21%), Byssochlamys (1.8%–52.14%), Thermoascus (5.75%–28.26%), unclassified_o_Eurotiales (4.04%–24.35%), and Aspergillus (0.15%–9.58%). Each round also had its own characteristic microbial genera. Fermentation parameters (starch, moisture, acidity, and reducing sugar) were related to core and characteristic microbial community succession. The core microbial communities affect the fermentation parameters, and fermentation parameters regulate the characteristic microbiome. This study may help improve the understanding of the evolution of microbial community and the relationships between microbiota and fermentation parameters in stacking fermentation during Jiang-flavoured Baijiu brewing.