Transcriptomics analysis reveals the high biodegradation efficiency of white-rot fungus Phanerochaete sordida YK-624 on native lignin

Lignocellulosic biomass is an organic matrix composed of cellulose, hemicellulose, and lignin. In nature, lignin degradation by basidiomycetes is the key step in lignocellulose decay. The white-rot fungus Phanerochaete sordida YK-624 (YK-624) has been extensively studied due to its high lignin degradation ability. It was demonstrated that YK-624 can secrete lignin peroxidase and manganese peroxidase for lignin degradation. However, the underlying mechanism for lignin degradation by YK-624 remains unknown. Here, we analyzed YK-624 gene expression following growth under ligninolytic and nonligninolytic conditions and compared the differentially expressed genes in YK-624 to those in the model white-rot fungus Phanerochaete chrysosporium by next-generation sequencing. More ligninolytic enzymes and lignin-degrading auxiliary enzymes were upregulated in YK-624. This might explain the high degradation efficiency of YK-624. In addition, the genes involved in energy metabolism pathways such as the TCA cycle, lipid metabolism, carbon metabolism and glycolysis were upregulated under ligninolytic conditions in YK-624. The first differential gene expression analysis of YK-624 under ligninolytic and nonligninolytic conditions was reported in this study. The results obtained in this study indicated that YK-624 produces more enzymes involved in lignin degradation and energy metabolism.