Characterisation and comparison of the microflora of traditional and pure culture xiaoqu during the baijiu liquor brewing process

Light flavour baijiu, one the three major types of liquor in China, is popular with consumers, particularly in northern China. To understand how microbial communities and physical and biochemical properties change during the brewing process, two groups of xiaoqu - traditional and pure culture - were used for fermentation. High-throughput sequencing (HIS) combined with isolation and identification of microorganisms were used to investigate the microbial community dynamics during the brewing process. The traditional xiaoqu group displayed higher acidity than pure culture xiaoqu group from day 9 to day 15. During the continuous brewing process, Bacillus, Lactobacillius and Lactococcus were the dominant bacteria. Bacillus exhibited higher abundance than lactic acid bacteria (LAB) from day 0 to day 6, then LAB exhibited higher abundance than Bacillus from day 9 to day 15. Lactococcus was the predominant LAB from day 0 to day 6 then Lactobacillius dominated and Lactococcus remained stable but with low abundance from day 9 to day 15. Although different xiaoqu were used during the liquor brewing process, similar microbial dynamics were found with these two groups and this may reflect environmental factors. This work provides microbial insight that may help improve liquor fermentation as well as liquor quality. (C) 2020 The Institute of Brewing & Distilling