Optimization of process parameters by response surface methodology in fungal phytase production utilizing rice straw

Abstract

Towards value- added utilization of agricultural waste, in this study, we explored phytase production using rice straw as the substrate. We tried optimizing the process parameters for solid state production of phytase by <i>Aspergillusniger</i> NCIM 612 adopting response surface methodology (RSM). The interactions of glucose (% w/w), ammonium nitrate (% w/w), fermentation temperature (°C) and an amount of substrate (g) were studied by Box-Behnken model to select and determine optimum levels. The model predicted 3.46% glucose, 0.93% ammonium nitrate, fermentation temperature 30.14°C and 4.14 g substrate to be the best conditions for maximum phytase production of 136.988 U/gds. These conditions yielded 137±0.21 U/gds phytase, 1.29 fold enhancement over the conventional methods of phytase production.