Comparison of microbial communities in the fermentation starter used to brew Xiaoqu liquor

To reveal the brewing mechanism of Sichuan Xiaoqu liquor, microbial communities in Xiaoqu, a saccharification and fermentation agent, were characterized using microbial isolation and identification techniques, MiSeq high-throughput sequencing and bioinformatics. From Xiaoqu commonly used in three different regions (Dazhu, Pengzhou and Hubei) in China, three yeast strains and seven moulds were isolated and identified. In addition, 17 bacteria and seven fungi were detected by high-throughput sequencing. In Xiaoqu from Pengzhou (Huaxi Xiaoqu), the dominant species were Weissella cibaria (85.52%) and Rhizopus stolonifer (94.98%). On the other hand, W. cibaria (17.64%), Staphylococcus sp. (53.17%), Saccharomyces cerevisiae (43.33%), and Candida fennica (38.52%) were preponderant in Xiaoqu from Dazhu (Sichuan Dazhu Xiaoqu). Finally, Xiaoqu from Hubei consisted mostly of W. cibaria (29.64%), uncultured Empedobacter bacteria (32.60%), R. stolonifer (18.90%), Cunninghamella bertholletiae (67.41%) and S. cerevisiae (10.95%). Clearly, the bacterial community was relatively more complex than the fungal community. However, the fungal content in Xiaoqu of the three different regions was consistent. The results indicate that different flavours from different regions may result mainly from the bacterial and fungal diversity in their Xiaoqu. (C) 2017 The Institute of Brewing & Distilling