Abstract: We aimed to understand the succession of the bacterial communities in Aspergillus-type Douchi during its fermentation and to explore the inherent relation with fermentation environment factors. In this study, The main physicochemical properties were determined, and the composition and succession of the bacterial communities were investigated by high-throughput sequencing and statistical analysis. The results showed that the total amount of microbes, pH, the contents of reducing sugars, total alcohols, and water gradually decreased during the fermentation process, whereas the total amount of acids increased; the temperature increased first and then decreased. Species annotation and diversity analysis revealed that Staphylococcus was the core genus during the entire fermentation process, with relative abundances in the range of 24.16% to 85.97%; the composition (in terms of diversity and uniformity) of the bacterial communities changed significantly, and significant variation in the uniformity was found among fermentation stages (P < 0.05). The correlation analysis showed that the fermentation environment affected the bacterial community succession of Aspergillus-type Douchi, with the main driving factors being reducing sugar content, temperature and pH. Considering the actual situation in the industrial production, temperature may be an important factor to be controlled in the future.

Key words: Aspergillus-type Douchi; high-throughput sequencing; bacterial community succession; physicochemical factors; redundancy analysis