Microbial and metabolomic mechanism of nano-TiO2 synergistic intercropping promote wheat straw decomposition and resistance to faba bean Fusarium wilt

This study investigated TiO 2 -nanoparticles (TiO 2 -NPs) as a bioprocess intensifier for lignocellulosic biomass valorization in engineered rhizosphere systems, elucidating the microbial and metabolic interaction mechanisms underlying synergistic wheat straw decomposition and soil-borne pathogen suppression. Through rhizosphere bioreactor experiments coupled with metabolomics and microbiome analysis, the functional interplay between TiO 2 -NPs amendment and intercropping faba bean-microbe interactions was revealed. Results showed that integrated TiO 2 -NPs treatment accelerated wheat straw decomposition by enhancing hydrolytic enzyme activities and NH 4 + -N availability, while concomitantly enriching lignocellulolytic and biocontrol-associated bacteria including Nocardioides , Sphingomonas , and Intrasporangium . These enriched bacteria demonstrated robust linkages with antibacterial metabolites (galactinol, sucrose, levan), indicating a metabolic coupling between biomass depolymerization and disease-suppressive functionality. This study provides mechanistic insights into the synergistic effects of intercropping systems and TiO 2 -NPs in promoting rhizosphere-based lignocellulose bioconversion and functional microbiome assembly through the regulation of hydrolytic enzyme activities, bioactive metabolites, and bacterial community dynamics.