GLUCOSE-OXIDASE BIOSYNTHESIS USING MYCELIUM OF ASPERGILLUS-NIGER IMMOBILIZED ON SEEDS

Fungal conidia were immobilized on seeds of wheat, rye, barley, peas, buckwheat and mustards. Spongy mycelia overgrowing the seed surfaces on mineral medium with glucose produced extracellular glucose oxidase (GOD); the highest production was reached on the wheat carrier (1.3 U/ml). Some culture conditions, temperature, agitation speed, the amount of support were optimized to improve the growth and enzyme biosynthesis by the immobilized mycelium. This procedure made also possible repeated batch enzyme production. As many as 8 subsequent 24 h batches could be fermented by using the same carrier with only small losses of GOD activity. The new optimized medium with sodium nitrate caused a significant increase in GOD activity produced by free cells of A. niger (193.6%) and by 122.4% in the case of the immobilized mycelium.