Effect of Different Culture Conditions and Inducers on Production of Laccase by a Basidiomycete Fungal Isolate Pleurotus Ostreatus Hp-1 under Solid State Fermentation

The production of laccase by an indigenous strain of Pleurotus ostreatus HP-1 was studied on solid state fermentation. Culture parameters such as type and concentration of substrate, inoculum size, moisture content, pH, surfactant presence, temperature, and nitrogen source were optimized by conventional “one factor at a time” methodology. A maximum laccase yield of 3952 U g of dry substrate optimized was obtained with wheat straw as substrate with five agar plugs as the inoculum, 60% moisture content, pH 5.0, surfactant concentration 0.015 gl, and nitrogen source (combination of L-asparagine and NH4NO3 at 10 mM concentration each) at incubation temperature 28C. Enhancement in laccase activity was achieved with the use of various aromatic inducers and copper sulphate. Highest laccase activity of 14189 U g of dry substrate was achieved using 0.28 mM copper sulphate under optimized conditions. Thus, the indigenous isolate seems to be a potential producer of laccase using SSF and can be exploited for further biotechnological applications. The process also promises economic utilization and value addition of agro-residues.