Immobilization of β-galactosidase on carrageenan gel via bio-inspired polydopamine coating

Abstract

In the context of diligent efforts directed to develop new polymeric matrices for enzyme immobilization, we developed carrageenan gel disks activated with bio-inspired polydopamine layer. The carrageenan gel disks were firstly treated with polycationic polymer (hyperbranched polyamidoamine) followed by a polydopamine layer. Such a layer can act as an active platform for the covalent immobilization of enzymes via Michael addition and Schiff base. The mechanical strength of the coated gel disks was obviously enhanced. β-galactosidase was successfully immobilized with a loading efficiency of about 52 %. Furthermore, the immobilized β-galactosidase exhibited enhanced activity at a broader range of pH and temperature. Additionally, the immobilized β-galactosidase preserved around 80 % of the initial activity during the eleven reusability cycles. Generally, activation of the gel disks with the bio-inspired polydopamine layer considered as a safe alternative to the glutaraldehyde due to its cytotoxic. Accordingly, the easily formed carrageenan gel disks coated with polydopamine could have potential as enzyme carrier in drug and food industries.