Purification and Properties of Acid β-D-Galactosidase from Corticium rolfsii

Abstract

An acid β-D-galactosidase was purified from the culture filtrate of Corticium rolfsii IFO 6146 by a combination of QAE-Sephadex A-50 and SP-Sephadex C-50 chromatography. The maximum activity of the enzyme towards p-nitrophenyl β-D-galactopyranoside was found to be at pH 2.0 to 2.5 and the enzyme was fairly active at pH 1.5 to 1.8. The enzyme was quite stable over a pH range 2.0 to 8.0 at 2°C for 72 hr. The enzymic activity was clearly inhibited by Hg²⁺. Km value was determined to be 3.84×10^-4_M, and V_max was calculated to be 6.9μ moles per min per mg for p-nitrophenyl β-D-galactopyranoside. Contrary to high activity on the synthetic galactoside, reaction velocity was small when the enzyme acted on lactose.