Glucose oxidase and catalase activities of Penicillium variabile P16 immobilized in polyurethane sponge

Conidia of Penicillium variabile P16 were immobilized in polyurethane sponge and used in repeated-batch processes in a fluidized-bed reactor. Optimal conditions for production of glucose oxidase and catalase were: inoculum size, 10%; glucose concentration, 80 g L(-1); Ca-carbonate concentration, 15 g L(-1); temperature, 28 degrees C and aeration rate, 4 V V-1 min(-1). In an extended repeated-batch process, glucose oxidase activity was highest after the fourth batch and catalase activity was highest after the fifth batch. Scanning electron microscopy showed that the fungus grew only in the interior of carrier particles.