Unraveling The Degradation Mechanism Of Four Fungi For Lignocelluloses With Different Structures

In this study,three white-rot fungal strains,Ganoderma lingzhi Cui9164,G.australe Dai11646 and Trametes pubescens Cui7571 and one brown rot fungal strain,Laetiporus ailaoshanensis Dai15655 were used to degrade lignocelluloses with different structures containing broad-leaved(Betula sp.)and coniferous(Larix sp.)substrates.By virtue of degradation by G.lingzhi Cui9164,T.pubescens Cui7571,and L.ailaoshanensis Dai15655,apparent increases in acid insoluble lignin content of broad-leaved substrate(Betula sp.),subsequent enzymatic hydrolysis efficiency,sugar yield,and crystallinity were observed as well as obvious pores and cracks on the surface of substrates were detected,as evidenced by two steps of acid hydrolysis,enzyme hydrolysis,scanning electron microscopy(SEM),fourier transform-infrared spectroscopy(FT-IR),and X-ray diffraction(XRD)analyses.In contrast,the degradation effect of Dai11646 exerted the lowest degradation efficiency for Betula sp.,which may be due to that this fungal species could not grow on Betula sp.The same degradation behaviors were also found in coniferous substrate(Larix sp.).Discriminatively,fungal degradation ability to coniferous substrate(Larix sp.)was ranked as follows: T.pubescens Cui7571 > G.australe Dai11646 > G.lingzhi Cui9164 > L.ailaoshanensis Dai15655。On the basis of variations measurement of chemical components,hydrolysis efficiency,surface morphology,functional groups and crystallinity of lignocellulosic materials,it was suggested that fungal biodegradation can improve the effective contact area of cellulase to cellulose surface,thus improving the bioconversion efficiency.In addition,it was proved to be highly scientific that the host selection of fungi with different species decay types.The findings would provide theoretical and technical support for fungi degradation of lignocellulose to achieve high value utilization of lignocellulose and lay a theoretical foundation for expanding the application field of wood decay fungi resources.