PURIFICATION AND CHARACTERIZATION OF A BETA-GLUCOSIDASE FROM STREPTOMYCES-LIVIDANS 66

An intracellular β-1,4-D-glucosidase (EC 3.2.1.21) was isolated from the mutant strain HP-3 of Streptomyces lividans 66 which produced about 12 times more enzyme than the wild-type strain. The purification was carried out by anion exchange column chromatography followed by high-performance liquid chromatography on DEAE and on molecular sieve columns. The enzyme is glycosylated and has an apparent M(r) of 51,000 and a pI of 4.3. Its activity was optimal at pH 6.5 and at a temperature of 40°C. The K(m) and the V(max) on cellobiose were 3.1 mM an 65.6 μmol min-1 mg-1 of enzyme.