Characterisation and comparison of the microflora of traditional and pure culturexiaoquduring thebaijiuliquor brewing process

Abstract

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 (HTS) 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. © 2020 The Institute of Brewing & Distilling Additional supporting information may be found online in the Supporting Information section at the end of the article.

Characteristics of the Microbial Community in the Production of Chinese Rice-Flavor Baijiu and Comparisons With the Microflora of Other Flavors of Baijiu

“…At the late stage of fermentation, the anaerobic environment is dominant, the nutrient content decreases, and the acidity and alcoholic content increases, which inhibit the growth of some microorganisms and lead to a decrease in species diversity. The changing pattern of microbial diversity is consistent with that in the brewing of strong- ( Tan et al, 2019 ; Guan et al, 2020 ), mixed- ( Liu and Miao, 2020 ), and light-flavor baijiu ( Dong et al, 2020 ).…”

“…are more likely to undergo homolactic fermentation, which is the main reason for the rapid increase in ethyl lactate content and only a small increase in acetic acid and ethyl acetate content at the late stage of fermentation. The main bacterial genera in the Xiaoqu light-flavor baijiu were Lactobacillus , Acetobacter , Weissella , Lactococcus , and Bacillus ( Dong et al, 2020 ; Hu et al, 2021a , b ). In strong-flavor baijiu, the main bacteria genera were Kosakonia , Lactobacillus , Weissella , Pediococcus , Pantoea , and Bacillus , which accounted for more than 86% of the bacterial abundance ( Guan et al, 2020 ).…”

“…It is currently unclear whether there are differences in the composition of the microbial communities in the production of these two flavor types of baijiu. In addition, there have been more studies of the brewing microorganisms of light- ( Dong et al, 2020 ; Hu et al, 2021b ), strong- ( Guan et al, 2020 ), and sauce-flavor baijiu ( Dai et al, 2020 ), but less of rice-flavor baijiu, and its brewing microbial composition has yet to be resolved. Therefore, in this study, high-throughput sequencing technology was used to analyze the microbial communities in the starters and production processes of rice-flavor baijiu to identify the core microbiota and study their effects on the microbial communities by combining with changes in physicochemical factors, such as flavor components.…”

Integrative Metagenomics–Metabolomics for Analyzing the Relationship Between Microorganisms and Non-volatile Profiles of Traditional Xiaoqu

“…However, Basidiomycota was predominantly dominant in AS (2.28%) and HS (1.77%; Figure 1B ). Firmicutes, Proteobacteria, and Actinobacteria were previously identified as the dominant bacteria in Xiaoqu (Wu H. et al, 2017 ), Xiaoqu jiu (Dong et al, 2020 ), and strong-flavored Baijiu fermentation ecosystems (Zou et al, 2018 ). Meanwhile, Ascomycota, Mucoromycota, and Basidiomycota occupy a major position in the brewing process of black glutinous rice wine (Zhao et al, 2020 ), Indian dry starters (Anupma and Tamang, 2020 ), and strong-flavor Baijiu Daqu (Guan et al, 2015 ).…”

“…Additionally, the abundances of Rhizopus and Phycomyces were 13.64 and 11.26% and 13.24 and 10.90% in AS and HS, respectively. Rhizopus , a strong amylase producer that degrades starch during Xiaoqu jiu production (Tang et al, 2019 ; Dong et al, 2020 ), was previously identified as the main fungi in Wuyi Qu (Liu et al, 2018 ). Conclusively, the microbiota detected in these Xiaoqu samples demonstrated significant differences in their structure and diversity, which might be due to differences in geographical environment, raw materials, and preparation technology (Du et al, 2019 ).…”