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

Figure 10

The effect of rotation rate on glucose isomerase production. Rotation rate has close relation with dissolved oxygen and nutrient diffusion in media. When the rotation rate increased from 80 to 120 rpm, the enzyme activity significantly increased (0.209 ± 0.004 and 0.248 ± 0.001 U/mg biomass, resp., ). We observed that the faster rotation rate (140–180 rpm) reduced the enzyme activity from 0.239 ± 0.010 to 0.205 ± 0.001 U/mg biomass (). Rotation rate 120 rpm was chosen as the optimal rotation rate for production of glucose isomerase. a, b, c, and d indicate the significant difference between groups.