A study on the whole cell immobilized glucose oxidase from Aspergillus niger

Heat treated whole cell of Aspergillus niger containing glucose oxidase-catalase system was entrapped in gelatin matrix crosslinked by glutaral-dehyde. The reaction characteristics of immobilized enzyme was studied in a fludized reactor. Heat treatment enhanced the stability and improved the properties of micellium for the immobilized process. The immobilized enzyme system showed the maximum activity at $35^{\circ}C$ and at pH 5.5. The optimum substrate concentration was 0.04M glucose. The activity of immobilized glucose oxidase was in proportion to the concentration of dissolved oxygen in reaction mixture as other reaction conditions were fixed. It was also demonstrated that the limiting factor for the activity of the immobilized glucose oxidase was the oxygen diffusion resistance which increases proportionally to the glucose concentration.