Optimization of Culture Conditions for the Production of Xylanase in Submerge Fermentation by Penicillium Citrinum Using Response Surface Methodology

In the present study Response surface methodology (RSM) was used to investigate the combined effect of relevant process variables to maximize the production of xylanase in submerge fermentation by Penicillium citrinum MTCC 2553. The process variables include pH (6.5, 7.0, and 7.5); temperature (25, 30, and 35°C); agitation speed (190, 200, and 210 rpm); and, substrate (xylan) concentration (0.70%, 0.75%, and 0.80%). A 2 factorial central composite design (CCD) using response surface methodology (RSM) was employed to obtain interaction between the process variables and optimizing these variables. Total 22 experiments were carried out in shake flask and a three dimensional response surface was generated to determine the effect of process variables on xylanase production. The optimal calculated values of tested variables for maximal production of xylanase were: pH 7.49, temperature 29°C, agitation speed 209 rpm, and substrate concentration of 0.75%. This approach for process parameter optimization yielded enhance xylanase activity by three folds compared to the unoptimized media.