Non-enzymatic modification of the crystalline structure and chemistry of Masson pine in brown-rot decay

Masson pine undergoes rapid degradation by brown-rot fungi, but how the fungus alters the microstructure of Masson pine cell wall is still unclear. In this study, Masson pine samples were incubated with Gloeophyllum trabeum to aid in characterizing changes in the crystalline structure of cellulose and chemical composition of wood in brown-rot decay. Fungal action resulted in an initial increase in wood cellulose crystallinity and crystallite width because of early removal of the more amorphous celluloses, followed by a decrease in crystallinity and crystallite size. All data suggest that hemicellulose, amorphous cellulose and crystalline cellulose are sequentially depolymerized via a non-enzymatic pathway, concurrent with early-stage changes in the rearrangement of cellulose chains and the diffusion of depolymerized less-crystalline polysaccharides out of the cell wall. Our work provides insight into the role of a non-enzymatic system in brown-rot decay as well as its potential application in lignocellulose preservation and biorefineries.