Cinnamic carbohydrate esters show great versatility as supports for the immobilization of different enzymes

Cinnamic carbohydrate esters were used to immobilize enzymes with different molecular and structural properties, including β-galactosidase, wild-type and recombinant horseradish peroxidase (HRP and HRP*, respectively). For β-galactosidase immobilization, cinnamoylated derivatives of inulin (INCN41 and INCN49 representing 41% and 49% of their hydroxyl groups, respectively) were prepared and cross-linked with d-glucosone cinnamate (GSOCN). Polymerization and cross-linking of the derivatives initially obtained was achieved by irradiation in the ultraviolet region, while immobilization and storage conditions were studied to ascertain good post-storage values and re-usability. The viability of these supports for immobilizing unglycosylated enzymes was also assayed. Recombinant HRP expressed in Escherichia coli is especially difficult to immobilize since its tertiary structure lacks the carbohydrate remains which normally act as the immobilization vehicle. Immobilization of HRP and HRP* on cinnamic carbohydrate esters involves a process of physical adsorption and intense hydrophobic interactions between the cinnamoyl groups of the support and related groups of the enzyme, a process which is independent of enzyme glycosylation. Both HRP and HRP* were successfully immobilized on GSOCN or SSCN (sucrose cinnamate). Using immobilized HRP, more than 70% of the initial phenol concentration was removed from a water solution. The results show that cinnamic carbohydrate esters are a promising support for peroxidase immobilization. They can be used for the treatment of wastewaters contaminated by phenolic compounds and for the immobilization of enzymes of a similar or different nature.