Response surface optimization of solid state fermentation for inulinase production from Penicillium oxalicum using corn bran.

Response surface methodology has been implemented for the utilization of corn bran for inulinase production by Penicillium oxalicum. CCRD of RSM with 15 runs was practiced to optimize three independent variables: moisture (70-90%), incubation time (4-8 days) and pH (5-8). However, other media constituents viz. inulin (1%), NaNO3 (0.2%), NH4H2PO4 (0.2%), KH2PO4 (0.2%), MgSO4·7H2O (0.05%) and FeSO4·7H2O (0.001%) were kept constant during solid state fermentations. Solid state fermentations were carried out at 30 °C at flask-level. A substantial inulinase production (77.95 IU/gds) was obtained under the optimized conditions i.e., moisture (80%), incubation time (6.0 days) and pH (6.5). Multiple correlation coefficient 'R2' for inulinase production was 1.00, which justifies good agreement between experimental and predicted values. Besides, 'R2' value close to one, also authenticates the validity of the model. The experimentation carried out at laboratory scale shown corn bran a good substrate for inulinase production by P. oxalicum.