Partial purification and characterization of a new intracellular β-glucosidase of Trichoderma reesei

A new intracellular beta-glucosidase was isolated from Trichoderma reesei. It was sequentially purified by (NH4)2SO4 precipitation and chromatography and rechromatography on Sephadex G-150. The enzyme has a mol.wt. of 98 000, optimal activity at pH 6.5, pI 4.4 and Km values of 6.7 mM and 3.3 mM for sophorose and cellobiose respectively. Possible functions of the enzyme may be regulation of cellulase induction and/or to serve as a proenzyme.