Chemically treated strain improvement of Aspergillus niger for enhanced production of glucose oxidase

The objective of research was to enhance the production of glucose oxidase through mutagenesis of Aspergillus niger. Among colony restrictors, triton X-100 and ox-gall were used and it was found that 1% ox gall was the best. In order to produce depressed mutants for enzyme production, 2-deoxy-D-glucose was used at 1 mg mL-1 in PDA plates. A few colonies were selected based on large clearance zones than wild type microorganism. Glucose oxidase positive strain was identified on agar plate with o-dianisidine and peroxidase. The size and color of zone is an index of the formation of glucose oxidase, giving rise a brown color. The results indicated that A. niger mutant BCM-8 and BCE-6 produced 9 and 6 mm enzyme diffusion zone with 282 and 202% increased activity, respectively.