Abstract:
On qualitative screening of the pure cultured bacteria isolate, oxidation of 2, 3, 5 - triphenly tetrazolium validated the presence of glucose isomerase. The bacteria isolate was then identified as Bacillus sp. based on morphology and molecular characteristics. Glucose isomerase was produced using a submerged fermentation system with glucose as the carbon source (for about 7days) with day 2 yielding the maximum enzyme activity of 41.349 μmol/min and a protein concentration of 0.939mg/ml. Incubation time of 30 minutes was obtained for maximum isomerization reaction at 1M substrate concentration. 80 % ammonium sulphate saturation was found suitable to precipitate proteins with glucose isomerase activity. After the purification process, specific activity of 120.258 U/mg protein and purification fold of 1.02 was obtained. The optimum pH and temperature on the partially purified enzyme was observed to be pH 7.0 and 80 °C, respectively while the kinetic parameters (Km and Vmax) were found to be 1.195 M and 243.90 μ mol/min respectively. Divalent metal ions such as, Mn2+, Ca2+, Co2+ and Mg2+ in a concentration dependent manner enhanced glucose isomerase activity, however, Cu2+ showed antagonist activity by inhibiting the activity of the enzyme. Results obtained from this study suggest that the glucose isomerase produced by Bacillus has outstanding properties making it suitable for industrial application
