Influence of medium components and metabolic inhibitors on glucose oxidase production by Aspergillus niger mycelium

Abstract

The effect of some medium components and metabolic inhibitors on glucose oxidase (GOD) production by mutant Aspergillus niger was studied in shaken culture. Altering the composition of the basal medium, particularly substitution of (NH4)2HPO4 for NaNO3, and lack of Mg2+ ions caused an increase in GOD activity by 269.6%. The highest yield of extracellular GOD activity of A. niger mycelium was obtained in the presence of hematin (1 mM), choline (40 mM) and Tween 80 (0.1%), which improved the activity of this enzyme by about 31.4-53.9%. A significant increase (68.3%) in intracellular GOD activity was found in the presence of sodium orthovanadate (1 mM). The time course of growth and enzyme production by A. niger in the optimized medium is also reported.