[Isolation and characterization of extracellular glucose oxidase from Penicillium adametzii LF F-2044.1]

Hydroxides of magnesium and zinc, aluminum oxide, zinc phosphate, and co-precipitated Ca3(PO4)2 and Mg(OH)2 were efficient in binding extracellular glucose oxidase (GO) of P. adametzii LF F-2044.1 in a culture liquid filtrate (CLF). Basic Al2O3 was the most appropriate adsorbent for GO isolation from the CLF of the fungus. A GO isolation method was developed, which allowed for obtaining an enzyme with a high degree of purification. Spectral properties of the enzyme, its catalytic activity, and stability were characterized. The GO of P. adametzii LF F-2044.1 exhibited high pH stability, retaining activity within the range 4.5-9.0. The rate that GO-catalyzed D-glucose oxidation increased as the temperature increased (up to approximately 60 degrees C). The catalytic activity and thermal stability of GO depended on its concentration in the medium. Under optimum conditions, the fractions GO-1 and GO-2 were characterized by KM values of 1.56 x 10(-2) and 2.19 x 10(-2) M, respectively; the corresponding values of kcat equaled 235.1 and 318.2 s(-1).