Bacteria of Xiaoqu from seven provinces in southern China

Xiaoqu, a pivotal starter in baijiu fermentation, was scrutinized across seven provinces in southern China to decipher its microbial composition. Employing high-throughput sequencing and plate isolation methods, microbial diversity and cultivable microbes were examined. Significant variations in both bacterial and fungal communities were unveiled among different Xiaoqu samples. A total of 24 bacterial species and 17 target fungal species were isolated and identified. Predominant bacteria included Bacillus (Bacillus substilis) and lactic acid bacteria (LABs), while fungal communities were dominated by yeasts (Saccharomyces cerevisiae) and various molds. Furthermore, correlations between microbial composition, physicochemical properties, and enzyme activities were explored, underscoring the pivotal role of LABs in acidity maintenance, and molds and yeasts in saccharification and fermentation process. These findings shed light on the microbial composition of Xiaoqu and its significance in baijiu production, offering potential microbial resources for the production of mechanical Xiaoqu via synthetic microbial community in future, contributing to baijiu fermentation efficiency, flavor diversity, and overall product quality.