OPTIMIZATION OF INOCULUM VOLUME, FERMENTATION MEDIUM AND AERATION RATE FOR THE PRODUCTION OF GLUCOSE OXIDASE BY UV MUTANT STRAIN OF ASPERGILLUS NIGER AN-14

In this study the effect of inoculum size, volume of fermentation medium and aeration rate was analyzed for UV mutated strain of Aspergillus niger AN-14 regarding enhanced production of glucose oxidase. UV treated 10 variants showing positive variations from parent strain were isolated and analyzed for glucose oxidase production using shake flask fermentation. Mutant strain AN-14 gave maximum production of glucose oxidase (44.61 U/g of cell mass) as compared to wild strain W-47 (21.74 U/g of cell mass). About 100% increase in the production of glucose oxidase was observed by the mutant strain. The experiments were up scaled and carried out in a 7.5 L capacity bioreactor with working volume of 5 L. It was concluded that 65% volume of total bioreactor, 5% inoculum of the total volume of fermentation medium and aeration rate of 0.8vvm were optimum for glucose oxidase production by the mutant strain. The optimized yields of glucose oxidase for wild and mutant strains were recorded as 26.48U/g of cell mass and 50.39 U/g of cell mass, respectively.