High-Throughput Sequencing Analysis of Microbiota and Enzyme Activities in <i>Xiaoqu</i> from Seven Provinces in Southern China

<i>Xiaoqu</i>, a pivotal starter in baijiu fermentation, provides the most microflora and enzymes to initiate and maintain baijiu brewing. This study aims to explore the differences in microbiota and enzyme activities among <i>Xiaoqu</i> samples from seven provinces in southern China using high-throughput sequencing, plate isolation, and activity detection. The analyses revealed significant differences in bacterial and fungal communities across the samples. A total of 22 bacterial species and 17 target fungal species were isolated and identified. Predominant bacteria included <i>Bacillus</i> (<i>Bacillus subtilis</i>) and lactic acid bacteria (LABs), while the fungal communities were primarily composed of yeasts (<i>Saccharomyces cerevisiae</i>) and various molds. The activities of α-amylase and glucoamylase varied significantly among the samples, and samples from HN1 and GZ2 exhibited the highest activities. Correlation analyses highlighted the pivotal role of LABs in maintaining acidity and the importance of molds and yeasts in the saccharification and fermentation processes. These findings shed light on the microbial composition and diversity of <i>Xiaoqu</i> and the critical role of microbes in baijiu production. Moreover, they suggested potential microbial resources for developing artificial <i>Xiaoqu</i> via synthetic microbial community in the future, enhancing baijiu fermentation efficiency and overall product quality.