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

Figure 7

The effect of pH on glucose isomerase production. In this study, we observed an increase of enzyme activity (0.176 ± 0.01 to 0.243 ± 0.01 U/mg biomass) along with an increase of pH value of induction medium (pH 5.5–pH 7.0). However, when pH increased from 7.5 to 8.0, we observed a decline of enzyme activity (from 0.194 ± 0.01 to 0.185 ± 0.01 U/mg biomass, resp.). From these data, we chose optimal pH value for glucose isomerase production was 7.0. a, b, c, d, e, and f indicate the significant difference between groups.