Biocatalysis by penicillin G acylase anchored on beaded macroreticular glycidyl methacrylate-divinyl benzene polymers: effect of pore structure on catalytic activity

Abstract

A series of macroreticular, beaded, glycidyl methacrylate (GMA) and divinylbenzene (DVB) polymers with variance in pore size distribution were synthesised by suspension polymerisation. The internal pore structure of the beads were altered by changing the mole ratio of GMA:DVB, porogen (cyclohexanol, hexanol) or its volume. The porosity was investigated by mercury intrusion porosimetry. The functional group were characterised by IR spectroscopy and wet analysis. The study shows a dependence of surface functional group, surface area and porosity on copolymer composition, porogen type and volume. Immobilisation of penicillin G acylase on the synthesised beads was investigated. The process parameters were optimised to attain good binding and maximum expression of penicillin G acylase. The immobilised enzyme was used in the production of 6-APA, a key intermediate in the production of semi-synthetic penicillins.