Developing a Novel Enzyme Immobilization Process by Activation of Epoxy Carriers with Glucosamine for Pharmaceutical and Food Applications

We describe the development of an effcient enzyme immobilization procedure based on the activation of epoxy carriers with glucosamine. This approach aims at both creating a hydrophilic microenvironment surrounding the biocatalyst and introducing a spacer bearing an aldehyde group for covalent attachment. First, the immobilization study was carried out using penicillin G acylase (PGA) from Escherichia coli as a model enzyme. PGA immobilized on glucosamine activated supports has been compared with enzyme derivatives obtained by direct immobilization on the same non-modified carriers, in the synthesis of different 3'-functionalized cephalosporins. The derivatives prepared by immobilization of PGA on the glucosamine-carriers performed better than those prepared using the unmodified carriers (i.e., 90% versus 79% cefazolin conversion). The same immobilization method has been then applied to the immobilization of two other hydrolases (neutral protease from Bacillus subtilis, PN, and bromelain from pineapple stem, BR) and one transferase (gamma-glutamyl transpeptidase from Bacillus subtilis, GGT). Immobilized PN and BR have been exploited in the synthesis of modified nucleosides and in a bench-scale packed-bed reactor for the protein stabilization of a Sauvignon blanc wine, respectively. In addition, in these cases, the new enzyme derivatives provided improved results compared to those previously described.