Abstract:

Complex microbial communities and metabolites play important roles in the formation of taste and flavor during
the fermentation process of traditional vinegar. The present study investigated the composition and diversity of bacterial
communities in the acetic acid fermentation process of Tianjin duliu mature vinegar using metagenomic approach. The
results showed that bacteria exhibited greater diversity in the early period than other microorganisms. Principal component
analysis revealed that Lactobacillus, Acetobacter and Nostoc had the main relationship with the acetic acid fermentation
process. The abundance of acetic acid bacteria increased as the fermentation proceeded, while lactic acid bacteria decreased.
The abundance of lactic acid bacteria was far more than that of other microorganisms, indicating that it might have important
functions for the formation of vinegar flavor.

Key words: traditional vinegar, metagenomics, microbial diversity, acetic acid fermentation, acetic acid bacteria, lactic acid bacteria