This study aimed to understand the effect of the processing environment and the highest temperature on the structure of microbial communities in Daqu liquors. The different characteristics of four different kinds of sauce-flavor Daqu liquors were investigated, including brewing characteristic parameters, microbial community structure and the composition of the volatile components.

The four Daqu samples used in this study were obtained from four different liquor factories. The name of Daqu are as follows: Luzhou Daqu (LZ), Guotai Daqu (GT), Langjiu Daqu (LJ) and Xiantan Daqu (XT).

A total of 16 PLFAs were detected from 4 Daqu samples, with the order of the total amount of PLFAs as LZ > GT > LJ > XT. The microflora of sauce-flavor Daqu was composed of fungi, Gram+ bacteria, and Gram- bacteria, with fungi as the predominant microorganisms. Moreover, samples with similar maximum temperature clustered as a group in cluster analysis. In summary, the characteristic parameters of brewing displayed a positive correction with the biomass; the composition of volatile compounds depended on the biomass of Gram+ bacteria.

This research has been published on Chinese Journal of Applied & Environmental Biology which was supported by Chengdu Institute of Biology.