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

Abstract

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.