LAUSR

Abstract Oyster mushrooms use different lignocellulosic substrates with different biological efficiency, whereas deep understanding of the molecular mechanism is lacking. The extracellular/intracellular proteomes, lignocellulosic composition were analyzed after 21-day cultivation of P. ostreatus in sawdust, cottonseed hull and corncob. Lignin and hemicellulose content of three substrates significantly decreased, and cottonseed hull showed the highest saccharification rate. 297, 333, and 312 soluble proteins were identified in hardwood sawdust, cottonseed hull and corncob, respectively. P. ostreatus mobilized the corresponding antioxidant and carbon metabolism pathways and produced more abundant ligninolytic enzymes, especially class II peroxidases, to accommodate lignin-rich substrate hardwood. Ligninolytic enzymes and carbohydrate oxidases showed higher expression levels in sawdust, while carbohydrate active enzymes were highly expressed in polysaccharide-rich cottonseed hull and corncob. These results suggested P. ostreatus adapts to different substrates through regulating extra/intracellular proteins expression, and cottonseed hull is a potential source for biorefinery and oyster mushroom cultivation.