Molecular characterization and overexpression of mnp6 and vp3 from Pleurotus ostreatus revealed their involvement in biodegradation of cotton stalk lignin

ABSTRACT

Fungal secretory heme peroxidase (Class II POD) plays a significant role in biomass conversion due to its lignin-degrading activity. In this study, genome-wide identification and bioinformatics were performed to analyze P leurotus ostreatus peroxidases ( PoPODs). A total of six manganese peroxidases (MnPs) and three versatile peroxidases (VPs) were obtained. Bioinformatics analysis and qRT-PCR showed that P. ostreatus mnp6 ( Pomnp6) and P. ostreatus vp3 ( Povp3) could be involved in lignin degradation. Both Pomnp6 and Povp3 transgenetic fungi showed significantly increased lignin degradation of cotton stalks. ¹H-NMR revealed that Pomnp6 and Povp3 may preferentially degrade S-lignin in cotton stalks and mainly break β- O-4′ bond linkages and hydroxyl. These results support the possible utility of Pomnp6 and Povp3 in natural straw resources and development of sustainable energy.

Abstract

Summary: Pleurotus ostreatus mnp6 and vp3 could degrade cotton stalk lignin and may preferentially degrade S-lignin.