The insight into instability mechanism of Jiangxiangxing Baijiu fermentation and the key functional regulation of Schizosaccharomyces pombe.

Jiangxiangxing Baijiu (JXXB) suffers from quality instability due to its complex spontaneous fermentation. This study compared fermented grains from excellent (Group-E) and normal (Group-N) workshops, identifying 28 volatiles as distinguished substances for quality. The core functional species were revealed by integrated meta-genomic and meta-transcriptomic sequencing analysis. Moreover, Schizosaccharomyces pombe and Acetilactobacillus jinshanensis were demonstrated as key functional contributors, while only Schi. pombe was highlighted active participation in both heap fermentation and pit fermentation. Notably, the proportions and doses of the functional yeasts, particularly Schi. pombe, were higher in Group-E, resulting in the higher quality. Furthermore, the industrial-scale bioaugmentation with Schi. pombe enhanced substrate utilization, elevated the production of flavor substances by 13.61 %, and improved the yield and excellent-quality proportion of base Baijiu by 32.18 % and 37.16 %, respectively. This study provided insights into the quality instability mechanism of JXXB, and fostered a foundation for ensuring consistent quality in solid-state fermentation.