In this study Manganese peroxidase, from novel fungus Agaricus bisporus A21 was purified, thermally characterized and its catalytic properties were investigated. The four step purification procedure i.e., ammonium sulphate precipitation, dialysis, ion exchange and gel filtration chromatography yielded 6.9 % activity with a purification factor of 8.48. The optimum temperature and pH of Manganese peroxidase for the oxidation of Manganese peroxidase were 40˚C and pH 6.0 respectively and remain active within the pH range of 3-10 after 24 h.The catalysis of MnSO4 by Manganese peroxidase was expressed by the Michaelis-Menten equation, suggesting that the maximum velocity (Vmax) was 231 U/mL and the Michaelis constant was 3.33mM revealing a binding site with higher substrate affinity. Enthalpy of activation decreased where Free energy of activation for thermal denaturation increased at higher temperatures. The partially purified manganese peroxidase shows excellent decolorization potential for Orange G (from 19.32 to 96 %) by the addition of natural mediator of wheat bran. UV–Vis spectrum and HPLC chromatogram clearly revealed that orange G transformed into different products. Thermostability and efficient decolorization suggest that this enzyme could be receiving substantial attention for its potential application in the biotransformation of organo-pollutants.

Ismat Bibi, Haq Nawaz, Shagufta Kamal, Kashif Jilani, Tahira Ruby Farooq Warsi and Shazia Nouren