Enhanced inulinase production by Streptomyces sp. in solid state fermentation through statistical designs

In this work, inulinase was produced by solid state fermentation by Streptomyces sp. using copra waste as carbon source. The nutrients were screened by Plackett–Burman design. From the pareto chart it was found that the nutrients, namely, soya bean cake, MgSO4·7H2O and (NH4)2SO4 were found to be most significant nutrient components. Hence, these three components were selected for further optimization using central composite design (CCD) in response surface methodology (RSM). The optimum conditions were soya bean cake: 0.05711 g/gds, MgSO4·7H2O: 0.00063 g/gds and (NH4)2SO4: 0.00772 g/gds. Under these optimized conditions, the production of inulinase was found to be 131 U/gds. The constants in the Michaelis–Menten equation were evaluated and high R 2 value implies the fitness of the model.