Abstract
A thermophilic fungus, Mucor miehei YH-10, isolated from manure was selected to produce thermostable β-glucosidase among 207 isolates. When Mucor miehei YH-10 was grown on wheat bran medium, the maximal accumulation of thermostable β-glucosidase was obtained after 4 days at 50°C, The β-glucosidase had an optimal temperature of 60°C and retained 73% of original activity after heating at 95°C for 5min. The β-glucosidase was fractionated by Sephadex G-100 chromatography into two components during the purification steps. These components were further purified by consecutive column chromatographies until they were homogeneous on disc electrophoresis. One retained 56% of original activity after heating at 95°C for 5min, whereas the other was completely inactivated after heating at 80°C for 5min.
