Abstract
In this study an extracellular manganese peroxidase (MnP) was isolated from culture filtrate of an indigenous fungal strain Ganoderma lucidum IBL-05 under static conditions using wheat bran as substrate. The enzyme was purified by applying successively ammonium sulphate precipitation, dialysis, ion exchange and gel filtration chromatographic techniques. Purification procedure resulted in 3.43-fold purification with corresponding specific activity of 539.59 Umg-1. The purified MnP elucidated single band in 43 kDa region on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The purified MnP showed optimum activity at pH 5 and 40°C temperature. The Km and Vmax for MnP toward MnSO4 as a substrate were found to be 65.5 mM and 640 UmL-1, respectively. It was observed that MnP activity enhanced by Mn2+ and Cu2+ and inhibited in the presence of Zn2+, Fe2+, EDTA and Cysteine to various extents with Hg2+ (most inhibitory). The purified MnP efficiently catalyzed the transformation of different synthetic textile dyes (Sandal-reactive dyes). Characterization revealed that MnP isolated from G. lucidum have potential to be used for myriad industrial and biotechnological applications.
Key words: Manganese peroxidase, Ganoderma lucidum IBL-05, purification, characterization, kinetics, dye decolorization
