Enhanced production of manganese peroxidase from clitopilus scyphoides employing statistical optimization for application in improving crop residue digestibility by ruminants

Abstract

Media components for the production of lignolytic enzyme MnP in the submerged fermentation from Clitopilus scyphoides were screened by PB design of experiments using main effects of different components and their percent contribution towards the MnP production. Total 31 components were considered in this study at temperature 30°C and incubation period of 5 days, in which Galactose, Malt extract, KH2 PO4 , NH4 H2 PO4 , CaCO3 , Tween80, Tartaric acid and sodium acetate were found to be significant components for MnP production. Further, response surface methodology was employed to optimize the media containing screened components along with temperature, pH and incubation days. The optimized medium contained 1.5% Galactose, 0.06%Malt extract, 0.02%KH2 PO4, 0.15%NH4 H2 PO4 , 0.003%CaCO3, 0.8%Tween80,0.005% MnSO4,0.88%Tartaric acid and 3% sodium acetate at temperature 31°C and pH 5.2 incubated for 5 days increased MnP productivity by 43 folds (43.2±1.29 U mL-1)when compared to un-optimized media (1.1±0.087 U mL-1). MnP produced was tested for lignolytic effects on different crop residues. Digestibility studies of different crop residues treated with crude MnP rich extracts indicated that a significant decrease in the percentage value of lignin and increase in in-vitro digestibility matter (at confidence interval 95%) when compared with untreated straws.