Lignocellulose degradation patterns driven by plant-derived carbohydrate-active enzymes

Lignocellulose is one of the most abundant renewable resources, with its recalcitrant structure posing a major barrier to efficient bioconversion. Plant-derived carbohydrate-active enzymes (CAZymes) might be a cost-effective alternative for lignocellulose pretreatment. This study aims to investigate the functional characteristics and application potential of plant-derived CAZymes in lignocellulose degradation. To specifically focus on plant-derived CAZymes, electron-beam irradiation was used to sterilize epiphytic microbiota of Pisum sativum, thereby excluding their interference. According to the result of enzymatic property analysis, plant-derived cellulases exhibited extensive acid tolerance and temperature adaptability. The purified enzyme (FpGH17) shares a strong evolutionary relationship with glucan endo-1,3-beta-D-glucosidase. Molecular docking revealed FpGH17 formed stable complexes with oligosaccharides via hydrogen bonds, with cellobiose showing the strongest binding affinity (-7.634 kcal/mol). Scanning electron microscopy and Fourier transform infrared revealed that plant-derived CAZymes damaged the physical and chemical structure. For hemicellulose, the side-chain residues were preferentially released under the action of plant-derived CAZymes. After enzymatic hydrolysis, saccharification achieved a high yield of water-soluble carbohydrate (159 g/kg DM, dry matter) and glucose (50.6 g/kg DM). This study aims to investigate the lignocellulose degradation driven by plant-derived CAZymes and highlights their potential as a sustainable and cost-effective pretreatment strategy for lignocellulose valorization.