Multi-omics Mechanistic Analysis of Efficient Lignocellulose Degradation by Pholiota adiposa Strain YAHS

Abstract This study focused on elucidating the lignocellulose degradation mechanism of Pholiota adiposa strain YAHS, aiming to provide theoretical basis and microbial resources for straw biorefining. Using the aniline blue-guaiacol plate screening method, 11 fungal strains were isolated from the Loess Plateau of northern Shaanxi. The highly efficient degrading strain P. adiposa YAHS was identified through DNS-based enzyme activity assays for cellulase and ligninase, combined with ITS sequence analysis. Whole-genome sequencing was performed using a hybrid approach integrating Illumina NovaSeq and Nanopore MinION platforms. Transcriptome-wide differential gene expression analysis was conducted via DESeq2, and untargeted metabolomics was carried out using UPLC-QTOF-MS. Multi-omics data were integrated to dissect the degradation pathways. Results showed that the genome of P. adiposa YAHS is 55.2 Mb in size, encoding 719 carbohydrate-active enzymes (CAZymes), with glycoside hydrolases (GHs) accounting for 37.4%. Multi-omics analysis revealed that this strain degrades lignocellulose into carbohydrates such as monosaccharides, oligosaccharides, and sugar alcohols through key enzymatic genes (e.g., exoglucanase, β-glucosidase, β-xylosidase, β-mannanase, monooxygenase) and metabolic pathways (e.g., sucrose/starch metabolism, fructose/mannose metabolism, anthranilate degradation). we preliminarily elucidated the lignocellulose degradation mechanism of fungi in the genus Pholiota through integrated multi-omics analysis, revealed the critical roles of key cellulolytic enzymes in this process, and provided important microbial resources and theoretical support for the development of novel biorefining technologies.