| Abstract: | Penicillin G acylase (PGA) is an important enzyme for the industrial production of 7‐amino‐3‐deacetoxy cephalosporanic acid (7‐ADCA) from cephalosporin G (Ceph‐G), and 6‐aminopenicillanic acid (6‐APA) from penicillin G (Pen‐G). These products are used for the manufacture of semi‐synthetic cephalosporins and penicillins. In this study, immobilized PGA was utilized to catalyze the conversion of Ceph‐G to 7‐ADCA. The optimal conditions were found to be an operating temperature of 45 °C, 0.2 M phosphate buffer, a substrate concentration of 30 mg cm?3 and a catalyst particle concentration of 0.01 g cm?3 (specific activity of 623.2 U g?1). Up to 45 °C the reaction was characterized by an activation energy of 38.66 kJ mol?1. Beyond 57.5 °C there was a sharp decline of activity, characterized by a deactivation energy of 235.88 kJ mol?1. Copyright © 2004 Society of Chemical Industry |
