New Insights for Biomass Utilization by Brown-Rot and White-Rot Fungi: the Differing Role of Hemicellulose Degradation in the Incipient Decay Process

Both brown-rot fungi and white-rot fungi are known to degrade hemicellulose in incipient decay, but the role of hemicellulose degradation in the wood decay process remains unclear. Here, Trametes versicolor and Gloeophyllum trabeum were used to colonize poplar wood for 3, 6, 9, 12, and 15 days to analyze the changes in chemistry, crystalline structure, and microstructure. Poplar wood incubated with G. trabeum (a brown-rot fungus) for 15 days released 13.5 mg/g of total soluble sugars, nearly three times the 4.5 mg/g observed in wood with T. versicolor (a white-rot fungus) incubation. All data indicate that G. trabeum has a limited capacity to utilize hemicellulose, resulting in diffusion that opens the cell walls and exposes cellulose for degradation. T. versicolor efficiently depolymerizes and utilizes hemicellulose, promoting mycelial growth and resulting in erosion-type decay. These findings contribute to a deeper understanding of fungal degradation mechanisms, offering valuable insights for modifying wood microstructures to develop novel wood-based functional materials and for improving biomass resource refining and wood protection.