Application of Doehlert Experimental Design for the Optimization of Medium Constituents for the Production of L-asparaginase from Palm Kernal Cake (Elaeis guineensis)

Abstract

Doehlert experimental design (DD) was applied for the optimization of medium constituents for L-asparaginase production by Yarrowia lipolytica NCIM 3472 in solid state fermentation (SSF) using palm kernel cake as the substrate. From the results of preliminary experimental runs, the three variables (glucose, moisture content, L-asparagine) have been identified as the potential variables for the production of L-asparaginase. Fifteen experimental runs designed by DD are carried out and the process response is modeled using a polynomial equation as function of these parameters. The proposed quadratic model for DD fitted very well to the experimental data that it could be used to navigate the design space according to analysis of variance results. The experimental values were in good agreement with predicted values and the correlation coefficient was found to be 0.9988. The optimal set of conditions for maximum L-asparaginase activity was as follows: moisture content of the substrate: 54.8622 (%), glucose concentration: 11.9241 (%w/w) and L-asparagine concentration: 1.0758 (%w/w). L-asparaginase activity at these optimum conditions was 39.8623 U/gds. STATISTICA 6.0 was used for implementing Doehlert experimental design.