Quantitative study on core bacteria producing flavor substances in Huangjiu (Chinese yellow rice wine)

In the process of Huangjiu fermentation, microbial succession plays an important role in quality control of Huangjiu. In this study, Lactobacillus acetotolerans was screened as internal standards, and the bacterial communities in Huangjiu fermentation were quantified definitively by high-throughput amplandin-qPCR. Based on the absolute quantitative results, multivariate statistics combined with flavor substance content analysis showed that Lactobacillus was significantly correlated with 11 core flavor substances. Macrotranscriptomics was further used to examine the transcription levels of genes related to flavor substances. The results showed that Lactobacillus was involved in the biosynthesis of several core flavor substances such as ethyl acetate during fermentation, and the correlation was strongest at the post-fermentation stage (day 5–23). It was confirmed that Lactobacillus was the core species in the formation of flavor substance in Huangjiu. This study provided valuable reference for further revealing the mechanism of microbial interaction during Huangjiu fermentation and improving the quality of Huangjiu.