No abstract

Beta-galactosidase (Beta-D-galactosidegalactohydrolase, EC 3.2.1.23) of Streptococcus cremoris H was partially purified by ammonium sulfate fractionation. Only 10% of the protein was recovered as enzyme protein and more than 50% of the enzyme in the crude extract was lost. A 2.6-fold purification only was achieved. The enzyme was most active at 65°C and recorded an optimum pH at 7.0. Km and Vmax with ortho-nitrophenyl beta-D galactopyranoside as the substiate were recorded as 0.384 mM and 12.6 pmoles/ mg proteinlmin. Manganese ions activated the enzyme. The enzyme was strongly inhibited by Hg++, Ca++, Ni++, and Ag+ as well as parachloromercuribenoate.

No abstract