Properties of Glucose Oxidase produced from a newly isolated strain of Aspergillus niger

Glucose oxidase (GOx) is a key enzyme used in many industries worldwide. To identify the GO x producer strain, Aspergillus niger was isolated from the Beehive and screened for its glucose oxidase-producing capability. Glucose oxidase was mass-produced by a submerged fermentation system. The activity of glucose oxidase was ascertained by the continuous spectrophotometric rate determination method. GOx was purified by (70%) ammonium sulphate precipitation, dialyzed, and gel filtration with 2.82, 3.54, and 3.69U/mg specific activity respectively. The enzyme exhibited an optimum pH range of 5.5 and a temperature optimum of 40°C. Ag²⁺ and Hg²⁺ had a remarkably inhibitory effect on the partially purified GOx, whereas Ca²⁺, Zn²⁺, and Mg²⁺ do not affect the enzyme activity. Cu²⁺ and Co²⁺ have a slight inhibitory effect on GOx. Kinetic characteristics of GOx from Aspergillus niger display Vmax as 40 U/ml, and Km as 0.12 mM. The findings on the properties of GOx exhibited optimum conditions for industrial applications.