Insights into the mechanism of lignocellulose degradation by versatile peroxidases

Abstract

Lignocelluloses are imperative structural components of plant cell wall and are profusely found in agricultural crop residues. The structural heterogeneity and recalcitrance of lignin limit the accessibility of cell wall carbohydrates for constructive exploitation. During the past decades, diverse lignin degrading enzymes were characterized to facilitate the utilization of lignocellulosic biomass for technological applications. Versatile peroxidases are unique among ligninolytic enzymes for their remarkably high redox potential and ability to oxidize lignin without the requisite of redox mediators. The hybrid structural architecture of this enzyme bearing functional features of lignin peroxidase and manganese peroxidase demonstrates its versatility in aromatics oxidation. This review summarizes the distinctive structural aspects of fungal versatile peroxidase in correlation to its oxidation of aromatic substrates besides emphasizing on the catalytic environment conducive for substrate oxidation. This review also focuses on the general strategies employed for production of this enzyme, its molecular framework, potential biotechnological applications of versatile peroxidase and prospects on enhancing the production of enzyme. Finally, the significance of this enzyme in improving the nutritive value of crop residues to promote ruminal productivity is highlighted.