Optimization of medium components for phytase production by E. coli using response surface methodology

The medium for recombinant phytase production by E. coli BL21 was optimized using response surface methodology. A 23 central composite experimental design was used to study the combined effect of the medium components, tryptone, yeast extract and NaCl. Addition of 2 g/l glucose to the medium greatly influenced the phytase production. The optimization of the medium has increased the phytase production by 1.2 times. The incorporation of 2 g/l glucose significantly enhanced the phytase production by 1.58 times, showing an overall 2.78 fold increase before optimization and other modifications of the medium. The optimized medium with glucose showed a highest phytase activity of 2250 U/l.ope