A protease from the medicinal mushroom Pleurotus sajor-caju; production, purification and partial characterization

Abstract

ObjectiveTo produce protease using solid state fermentation from Pleurotus sajor-caju. MethodsOptimization of saccharification conditions like time, pH, temperature, inoculum size, different carbon sources and its concentration, various nitrogen sources and its concentrations were studied. ResultsThe results showed that the optimum conditions for maximum protease production under SSF (Solid State Fermentation) by Pleurotus sajor-caju was found to be on the fourth day of incubation, pH, 7; temperature, 30°C, 3%; corn as substituted carbon source; 0.8% ammonium nitrate as nitrogen source concentration. Protease was partially purified by ammonium sulphate precipitation (70% saturation) to 2.72 fold with recovery of 53% characterized for few properties. Homogeneous preparation of protease from the culture filtrate of the fungus has been achieved using ammonium sulphate precipitation, anion exchange chromatography on DEAE cellulose. The purified enzyme preparation gave a single protein band in SDS-PAGE analysis indicating a molecular weight of 48 kDa. The purified enzyme exhibited its optimal activity at 60 °C and at pH 8. Metal ions (Ca2+ and Na 2+) caused moderate reduction in enzyme activity. ConclusionsConsidering the importance and application of the proteases, this study provides better understanding of condition for the activity of protease by fungal culture.