Glucose oxidase is an active oxygen generating species enzyme. It is used in food and pharmaceutical industries, clinical and analytical biochemistry laboratories for the determination of glucose level in different biological fluids. Due to its high range of applications, its production from different microbes has been reported. Mutagenesis/strain improvement is an important tool to develop the microbes with improved potential for the production of different industrially important products. Aspergillus niger is a potential producer of many important enzymes including glucose oxidase. In this regard, physical and chemical mutagenesis of Aspergillus niger has been performed for the hyperproduction of glucose oxidase. Now fermentation and optimization of the conditions for the hyperproduction is in progress.
Diabetes mellitus is the metabolic problem and is prevalent in many parts of the world especially in developing countries. Recent studies indicate that in developing countries one in ten deaths in economically productive individuals aged 35-64 years can be attributed to diabetes. The proportion of undiagnosed diabetes varies and is often higher than 50% (WHO, 2003). In year 2000, diabetic patients in Pakistan were reported to be 5.2 million, and Pakistan has been rated 6th in list of highest number of estimated cases of diabetes. According to this condition in year 2030, Pakistan would be 5th in ranking with 13.9 million diabetic cases and an increase of 37%. Glucose oxidase is most widely used in the glucose determination kits and biosensors. Local production of these kits/ dip-sticks, where glucose oxidase is used, is a greater need of the country.
- To produce the mutant of Aspergillus niger for the hyperproduction of glucose oxidase.
- Optimization of conditions for the production of glucose oxidase.
Aspergillus niger was isolated from the various sources that was subjected to mutagenesis by using radiations and various chemicals. The optimum dose and mutants of Aspergillus niger having the potential to hyperproduce glucose oxidase were screened using the selective marker (2-deoxy D-glucose). Optimization of different conditions for the production of glucose oxidase is in progress. The enzyme will be produced under these optimized conditions and purified by different chromatographic techniques. Then purified enzymes will be subjected to kinetic and thermodynamic characterization.
Results and Discussion
Various mutant derived strains have been screened, after mutagenesis of the Aspergillus niger having the potential to hyperproduce glucose oxidase. These mutant derived strains are being used for production of enzyme through submerged fermentation and the optimization of conditions to get the maximum yield of enzyme is in regard in progress.
Up-till now glucose oxidase mutants have been selected and production of enzyme through fermentation is in progress.
It is recommended that mutagenesis is a cost-effective procedure to get the mutant derived strains having the ability of many fold increased production of glucose oxidase. Such enzyme with improved characteristics like increased activity, thermal stability, resistance to environmental factors etc. can be used in glucose estimation kits/dip-sticks or in other industries.