Purification and biochemical characterization of two extracellular peroxidases from Phanerochaete chrysosporium responsible for lignin biodegradation

•A novel method for simultaneous purification of LiP and MnP has been proposed.•Optimal pH and temperature for LiP and MnP were determined.•Metallic ions affect differently LiP and MnP activities.•The kinetic parameters of LiP towards VA and MnP towards Mn2+ were determined.

Two extracellular peroxidases from Phanerochaete chrysosporium, namely a lignin peroxidase (LiP) and manganese peroxidase (MnP), were purified simultaneously by applying successively, ultrafiltration, ion-exchange and gel filtration chromatography. LiP and MnP have a molecular mass of 36 and 45 kDa, respectively. The optimal pHs for LiP and MnP activities were 3.0 and 4.5, respectively. Both peroxidases showed maximal activity at 30 °C and moderate thermostability. MnP activity was strongly inhibited by Fe2+, Zn2+, Mg2+ and Hg2+, and enhanced by Mn2+, Ca2+ and Cu2+. LiP activity was enhanced by Ca2+, Na+ and Co2+ and it was inhibited in the presence of K+, Hg+, Fe2+, Mg2+ and high concentrations of Cu2+ and Zn2+. The Km and Vmax for LiP toward veratryl alcohol as a substrate were 0.10 mM and 15.2 U mg−1, respectively and for MnP toward Mn2+, they were respectively 0.03 mM and 25.5 U mg−1. The two peroxidases were also able to break down rice lignin in a small-scale solid state treatment system. Data suggest these two peroxidases may be considered as potential candidates for the development of enzyme-based technologies for lignin degradation.