Anaerobic self-induced fermentation: a green bioprocessing strategy for enhancing extraction efficiency and bioactivities of flavonoids from Erigeron breviscapus (Vant.) Hand-Mazz

Erigeron breviscapus (Vant.) Hand-Mazz possesses anti-inflammatory and antioxidant properties, yet its therapeutic application is limited by the low yield of active components. Fermentation technology offers a promising strategy for enhancing the enrichment of these bioactive compounds. In this study, anaerobic self-induced fermentation was identified as the most effective approach among 12 evaluated fermentation strategies. Under optimized conditions, this method markedly increased the production of scutellarein-achieving a 20.35-fold enhancement-while reducing microbial α-diversity and inducing notable community restructuring, characterized by a shift from Proteobacteria to Firmicutes in bacteria and from Ascomycota to Basidiomycota in fungi. Metabolomic analysis revealed 223 differentially expressed metabolites, primarily enriched in flavonoid biosynthesis and phenylalanine metabolism pathways. Key bacterial genera, including Clostridium and Bacillus, showed strong correlations with increased flavonoid accumulation. Furthermore, the anaerobically self-fermented extract exhibited significantly enhanced antibacterial and antioxidant activities. These findings demonstrate that anaerobic self-induced fermentation represents an effective and targeted bioprocessing strategy for amplifying the bioactivity and therapeutic potential of E. breviscapus.