Abstract

Versatile  Peroxidases  are  high  redox  potential  peroxidases  capable  of  degrading  lignin  of lignocellulosic crop residues. Hence Versatile Peroxidases are prominent biocatalysts in upgrading lignocellulosic biomass for biotechnological applications. In the interest of exploiting the potential of Versatile Peroxidase in improving the digestibility of crop residues through delignification, a novel Versatile Peroxidase was purified and characterized from the immobilized cultures of native isolate Lentinus squarrosulus. The enzyme was purified with a specific activity of 62 U/mg through ion exchange and gel filtration chromatographic procedures. The enzyme possessed high affinity towards RB5 and manganese with a Km value of 6.84 μM for RB5 and 0.15 mM for manganese. The optimum temperature for oxidation was identified to be 30°C and optimum pH for manganese and RB5 oxidation was 5 and 3 respectively. Reactivity of the enzyme towards diverse substrates was investigated besides studying the effect of metal ions and inhibitors on RB5 oxidation. The enhanced potential  of  this  purified Versatile  Peroxidase  in  biodegradation  of  crop  residues  was demonstrated through augmentation of digestibility of finger millet and paddy straws by 20%.The results demonstrated that Versatile Peroxidase from Lentinus squarrosulus is capable of enhancing the nutritive value of crop residues through delignification.

Keywords

biodegradation, versatile peroxidase, natural substrate, lignin, white-rot fungi, detergent