Multi-omics-based metabolomic kinetics study of corn stover fermented by combined probiotic and enzymatic treatment

This study employed metabolomics to systematically investigate the dynamic changes of metabolites during the Probiotics-enzyme composite fermentation of corn stover. The results showed that the early fermentation stage was primarily driven by indigenous microorganisms. As fermentation progressed, the abundances of Firmicutes and Bacillus gradually increased, becoming the core functional microbiota, and their metabolic activities significantly lowered the feed pH. Additionally, Burkholderiaceae and Rhizobiaceae played pivotal roles in enhancing the crude protein content, while microorganisms such as Desulfobacterota, Erwiniaceae, Monascaceae, and Burkholderiaceae effectively degraded fiber components, thereby improving the feed’s nutritional value. To elucidate the mechanisms underlying metabolic dynamics, metabolomics analysis was conducted on days 7, 14, 21, and 28 of fermentation. The study found that during the early stage (days 7–14), the metabolism of peptides and sugar alcohols was synergistically regulated by various exogenous microorganisms. In contrast, during the mid-to-late stages (days 14–28), Firmicutes and Bacillus gradually dominated the synthesis and transformation of organic acids and secondary metabolites. By integrating prior microbiome data, this study systematically reveals the correlation mechanisms between dynamic metabolite changes and microbial communities, providing a crucial theoretical basis for understanding feed conversion rules during bacteria-enzyme composite fermentation of corn stover.