Medium Optimization for Recombinant Soluble Arginine Deiminase Expression in Escherichia coli Using Response Surface Methodology

Objective: Optimization of the medium for recombinant arginine deiminase production in E. coli was performed using response surface methodology. This is the first study of optimization of recombinant arginine deiminase production in E. coli by the use of response surface methodology. Methods: A Mycoplasm arginine deiminase gene was computationally optimized and inserted into pET-3a (+) expression vector. The synthetic pET3a-arginine deiminase construct was cloned and overexpressed in E. coli. The effect of glucose, NH4Cl and MgSO4.7H2O concentrations on the expression of intracellular soluble arginine deiminase was investigated using central composite design (CCD). Results: The maximum arginine deiminase activity (U/mL) was obtained in optimal concentrations g/L of glucose, 6.6; NH4Cl, 1.81; MgSO4.7H2O, 0.94; KH2PO4, 3.0; Na2HPO4, 6.78; NaCl, 0.5; CaCl2, 0.1 mL/L (1M), which was about 6.6 fold higher than that in M9 standard medium. Conclusion: The obtained result can be utilized for large-scale production of this enzyme and related recombinant protein.