• • Medium MBG ratio (1:2 v/v) significantly increased fungal Shannon index and evenness (p<0.05), while high ratio (1:1) suppressed bacterial diversity, indicating a non-linear dose-response and optimal application threshold.
• • MBG addition enriched Cyanobacteria and beneficial functional groups (e.g., nitrogen-fixing bacteria, Bacillus), enhancing nutrient cycling potential in degraded mine soil.
• • Co-occurrence network analysis showed that the medium ratio (1:2) maximized network complexity, modularity, and average degree for both bacteria and fungi, suggesting improved microbial community stability and resilience.
• • Functional prediction revealed significant enrichment of pathways for lipopolysaccharide biosynthesis, nitrotoluene degradation, and plant-pathogen interactions under medium MBG, alongside increased saprotrophic and ectomycorrhizal fungi, indicating enhanced organic matter decomposition and plant-microbe symbiosis.