Characterization of glucose Oxidase from Penicillium chrysogenum MDC 8358: Prospects for application in food industry

Abstract

Backgrounds: Food enzymes play a crucial role in enhancing specific food attributes, such as improving texture, eliminating toxins and allergens, producing carbohydrates, and enhancing flavor and appearance characteristics. Glucose oxidase (GOX) catalyzes the oxidation of glucose to produce gluconic acid and hydrogen peroxide, making it applicable in various practical scenarios. This enzyme could be utilized to eliminate glucose, thereby facilitating the creation of functional food suitable for individuals with diabetes and glucose intolerance.Our main goal was to characterize GOX from a Penicillium chrysogenum strain isolated from Armenian ecosystems.Methods:GOX of P. chrysogenum MDC 8358 was obtained by surface fermentation using glucose as a carbon source.  The enzyme was purified 230-fold to homogeneity using a three-step purification scheme consisting of ion exchange, adsorption, and gel filtration chromatography.  Results:The specific activity of the purified enzyme reached 271.2 U/mg. GOX from P. chrysogenum MDC 8358 has shown to be dimeric with a molecular weight of 135.5 kDa, consisting of two equal subunits with a molecular weight of 70 kDa. Isoelectric focusing has revealed a pH of 4.6. The enzyme has displayed a temperature optimum of 40 °C, and a pH optimum of 6.8, being more thermostable at acidic pH. Characterized GOX was highly specific for β-D-glucose and has shown only minor activities to mannose, xylose, and galactose. Keywords:Penicillium chrysogenum MDC 8358, surface fermentation, glucose oxidase, purification, characterization, functional food preservation