Fungus-mediated bacterial survival and migration enhance wood lignin degradation.

Bacterial-fungal interactions are increasingly recognized as a key factor in wood decomposition; however, the specific mechanisms underlying these interactions remain unclear. In this study, vanillic acid-utilizing bacteria were isolated from decayed wood colonized by the white-rot fungus IMPORTANCE: White-rot fungi are central to lignin degradation in forest ecosystems; however, the ecological roles of coexisting bacteria in solid wood environments remain poorly understood. Here, we show that the white-rot fungus Trametes versicolor facilitates bacterial migration and long-term survival in wood, enabling bacteria to access fungal-derived aromatic and carbohydrate compounds. Additionally, these bacteria may enhance fungal ligninolytic activity by metabolizing phenolic and sugar intermediates that could otherwise accumulate and affect fungal metabolism. This mutualistic interaction suggests a spatially organized metabolic cooperation that may accelerate wood decomposition. Our findings highlight a novel perspective for bacterial-fungal interactions in structured lignocellulosic substrates and inform microbial strategies for efficient biomass degradation in natural and engineered systems.