Abstract:
Effective degradation of lignocellulose is a key step for lignocellulosic biorefining. Cellulases and xylanases used for lignocellulosic degradation in industry come from filamentous fungi, but fungal enzyme yields are quite low. Understanding how filamentous fungi highly produce cellulases and xylanases is of great significance to improve cellulase and xylanase yields via genetic engineering. In present work, we identified a gene POX02968 regulating cellulase and xylanase production in Penicillium oxalicum. The P. oxalicum mutant ΔPOX02968 decreased the production of cellulases(filter paper cellulase, p-nitrophenyl-β-cellobiosidase, carboxymethylcellulase and p-nitrophenyl-β-glucopyranosidase) and xylanases to various degrees compared with the parental strain ΔPoxKu70 when cultivated on Avicel, ranging from 13.3% to 48.7%. Additionally, the gene POX02968 was found to be involved in fungal growth and sporulation. Deletion of the gene POX02968 in P. oxalicum resulted in the reduction of extracellular proteins. Protein sequence alignment analysis indicated that POX02968 contained a CSN8_PSD8_EIF3 K domain, speculating that it encoded the translation initiation factor 3 subunit K.