Effect of pH on LACBS activity. X-axis shows the pH while Y-axis shows the LACBS activity (%). Enzyme activity was examined in 50 mM of each of sodium acetate buffer (pH 3-5), Sodium phosphate buffer (5-7), Tris-HCl buffer (7-9) and Glycine/NaOH buffer (9-10) using benzylpenicillin (5μM) as a substrate.