Different selectivity and biodegradation path of white and brown rot fungi between softwood and hardwood

Abstract

Abstract The biodegradation path and mechanism of wood vary depending on diverse fungi and tree species, and fungi possess selectivity in degradation of versatile wood components. In order to clarify the actual and precise selectivity of white rot and brown rot fungi and the biodegradation path in different tree species, softwood (Pinusand C. lanceolata) and hardwood (Populus and H. brasHiensis) were subjected to decay test by white rot fungi T. versicolor, and brown rot fungi G. trabeum and R. placenta with various decay periods.The results showed that the white rot fungi caused selective rot in softwood, which preferentially degraded wood hemicellulose and lignin, but cellulose was retained selectively. Conversely, the white rot fungi caused simultaneous rot in hardwood, which resulted in a rather uniform depletion of cellulose, hemicellulose and lignin. Both brown rot fungi preferentially degraded carbohydrates, but R. placenta had a selectivity for the degradation of cellulose. In addition, microstructure observation showed that both white rot and brown rot infected wood parenchyma cells via pits, and the vessels were the primary paths for spread of mycelium. The research outcomes serve as fundamental knowhows for effective bio-engineering of bioresources, and utilization and protection of bio-products.