Characteristics of microbial community succession and functional metabolite accumulation during microaerobic fermentation of high-sugar-load fruit and vegetable residues: Potential implications for guiding home production of environmental-friendly bioactive fertilizer

Household fermentation tanks offer simple, low-cost solutions for fruit and vegetable waste utilization, yet staged metabolite formation during sugar-mediated fermentation remains understudied. Using metagenomic and metabolomic approaches, we characterized microbial succession and metabolite dynamics over 28 days. Three phases emerged: substrate activation (1-7d) with Enterobacter / Escherichia dominance producing organic acids; metabolic transition (8-21d) with Lactiplantibacillus proliferation (312.5% increase) accumulating phytohormones 3-hydroxycinnamic acid (2.84-fold) and adenine (1.38-fold); functional stability (21-28d) establishing Lactiplantibacillus-Acetobacter synergy enriching antioxidants and antimicrobial peptides. Multi-omics analysis revealed strong correlations between amino acid metabolism and functional metabolites ( r = 0.78, p < 0.01). Fermentation broth (1:500 dilution) enhanced lettuce germination to 92.22% ( p < 0.05).Although the potential of household agriculture is demonstrated through staged microbial community development and the formation of bioactive products, functional characteristics still need to be verified in the soil-plant system beyond seed germination assays. • Household fermentation converts fruit/vegetable waste to bioproducts (7-28d). • Overall from sour to fruity to vinegar; functional metabolites peak at day 21 with 17 bioactive peptides and 22 antioxidants in fermentation broth. • 21-28d fermentation broth shows abundance of Lactiplantibacillus 62.67%, Enterobacteriaceae declines to 0.5%, total phenols reach 3.53 mg GAE/mL, 3-fold antioxidant increase. • Semi-sealed microaerobic 28d produces stable functional metabolites. • 28d fermentation broth at 1:500 dilution achieves 92.22% lettuce seed germination with 19.6% root elongation; 1:50 concentration inhibits germination.