Research Article

Optimization of Fermentation Conditions and Media for Production of Glucose Isomerase from Bacillus megaterium Using Response Surface Methodology

Figure 3

The effect of the concentration of K2HPO4 on glucose isomerase production. Enzyme activity was significantly increased after supplement with 0.2% of K2HPO4 as compared to medium without K2HPO4. However, we observed a decline of enzyme activity while the concentration of K2HPO4 was adjusted from 0.3 to 0.5% (0.225 ± 0.002 and 0.207 ± 0.005 U/mg biomass, accordingly, ). We chose the optimal concentration of K2HPO4 is 0.2%. a, b, c, and d indicate the significant difference between groups.