Patterns of lignocellulose degradation and secretome analysis of Trametes trogii MT

Abstract

A basidiomycete strain MT showing lignin degradation capability was isolated and identified as a Trametes trogii strain, based on the morphological characteristics and the ITS 5.8S sequence. Enzyme production by the organism under liquid fermentation and during the decay process of a 120-day incubation period on Populus wood was studied. The results showed that the strain can produce high activities of laccase and manganese peroxidases, but no lignin peroxidases, and has the ability to simultaneously degrade lignin, cellulose, as well as hemicellulose of poplar wood. The decay pattern and process were explored using scanning electron microscopy and infrared spectroscopy. The results showed that the poplar wood is decomposed from the lumen to the middle lamellae, all the wood cell wall components are degraded, and the lignin and carbohydrate decay with no obvious differences in the levels of degradation. The decay patterns of MT in poplar wood showed the simultaneous type characteristics. The secretome of MT was surveyed using a shotgun strategy, and 65 proteins were assigned unambiguously, including the proteins with the functions of carbohydrate metabolism, cell wall and lignin degradation, fatty acid metabolism, protein metabolism and other functions. The secretome data showed that the fungus might have a complex enzymatic system implicated in lignocellulose degradation. The information presented in this paper is helpful to better understand the lignocellulose degradation mechanisms of T. trogii strains.