Natural polymers: suitable carriers for enzyme immobilization

Enzyme immobilization onto support carriers has the potential to overcome some of the limitations of soluble enzymes in practical applications. Various materials have been used as carriers, such as inorganic matrices, as well as natural and synthetic polymers. Production of carriers from natural biopolymers and their derivatives has been the focus of research worldwide, and a summary of their applications for enzyme immobilization is presented in this paper. Enzymes, or cells as an enzyme source, are entrapped inside a three-dimensional polymeric network, called a hydrogel, that is able to retain large amounts of water. This network can be formed by chemical cross-linking, ionotropic gelling in the presence of cation, or in thermo reverse polymerization, depending on the polymer in use and its physico-chemical characteristics. The most frequently used biopolymers as carriers for immobilization include alginate, cellulose, chitosan, collagen, xylan, pectin, and others