Comparative analysis of the microbial community structure in light-flavor Daqu in Taiyuan and Suizhou regions, China

In this study, we comparatively analyzed the microbial community structure of light-flavored Daqu (LFD) from Taiyuan and Suizhou regions using a combined strategy of single-molecule real-time sequencing and pure culture techniques. The results indicated that the dominant bacteria and fungi in all LFD were Bacillus licheniformis (22.61%) and Saccharomycopsis fibuligera (80.98%), respectively. The abundance and diversity of fungi were significantly lower in the LFD from Taiyuan region (Taiyuan-LFD) (p < 0.05). The LFD from both regions exhibited differences mainly in terms of lactic acid bacteria and thermophilic flora; Leuconostoc were significantly enriched in the Taiyuan-LFD, whereas Weissella, Thermoascus aurantiacus, and Thermoactinomyces sanguinis were significantly enriched in the LFD from Suizhou region (Suizhou-LFD) (p < 0.05). The correlating network between the microbiota of the Suizhou-LFD was denser than the Taiyuan-LFD. The core microorganisms of the LFD in both regions were mainly Ba. licheniformis, Burkholderia contaminans, and Saccharomycopsis fibuligera. Bacillus, lactic acid bacteria, and yeast isolated from all samples mainly consisted Ba. licheniformis (28 strains), Pediococcus pentosaceus (22 strains), and Saccharomycopsis fibuligera (44 strains), respectively. This study provided insights into the variations in microbiota in the LFD from different regions and laid the foundation for screening excellently suited functional microorganisms for brewing.