Purification of a new manganese peroxidase of the white-rot fungus Schizophyllum sp. F17, and decolorization of azo dyes by the enzyme

The manganese peroxidase (MnP) was isolated and purified from Schizophyllum sp. F17 on pinewood solid-state cultures. Fractionation of MnP was performed by Sephadex G-75 gel filtration chromatography followed by DEAE-cellulose anion exchange chromatography. This purification attained 3.8% activity yield with a purification factor of 9.2. According to data on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), the molecular weight of the enzyme was 48.7 kDa. The enzyme was a glycoprotein with 18% of its weight in carbohydrates. The optimum pH and temperature of purified MnP for oxidation of DMP were 6.8 and 35 °C, respectively. This enzyme was stable in the pH range 4.0–7.0, at 25 °C for 1 h incubation period. The effects of possible inhibitors and activators of enzyme activity were investigated. The Km values of MnP for Mn2+, H2O2, guaiacol, ABTS and DMP were 35.2, 6.7, 13.1, 47.8 and 122.9 μM at pH 4.5, respectively. The azo dyes such as Congo Red, Orange G and Orange IV were efficiently decolorized using the MnP purified.