Development of novel support for penicillin acylase and its application in 6-aminopenicillanic acid production

Abstract

There is an ever-increasing demand for the β-lactam bulk intermediate 6-aminopenicillanic acid (6-APA) that has wide applications in the synthesis of newer generations of semisynthetic penicillins. It is commercially synthesized by biocatalytic transformation using penicillin acylase. Since the enzyme is soluble, immobilization on a solid porous support is necessary to make the catalyst recycleable and the process profitable. In this study, we developed a novel support of siliceous foam entrapped in a polymer matrix. Penicillin acylase was covalently immobilized on aminopropyl functionalized mesocellular foam silica (MCF) and was further cross-linked using glutaraldehyde without deactivation and upto 95% efficiency. The resulting biocatalyst had an activity of 1185 IU. mg−1 and demonstrated improved resistance to the substrate and product inhibition. These parameters along with improvement in pH and thermal stability enhanced 6-APA yield by 20% in beads. Intrinsic kinetic parameters were calculated from the developed rate equation to deduce enzyme catalytic mechanism.