A Health-Friendly Strategy for Covalent-Bonded Immobilization of Pectinase on the Functionalized Glass Beads

In recent years, polyaldehyde polysaccharides have received an increasing attention as an ideal cross-linker which their aldehyde groups can be crosslinked with amino groups of enzyme. In this study, pectinase was covalently immobilized on the glass beads by polyaldehyde pullulan as the resulting product from periodate oxidation of this polysaccharide and by glutaraldehyde as a common cross-linker. Polyaldehyde pullulan had an aldehyde content of 19.9 +/- 1.3%, which was confirmed by FTIR. The protein content of glass beads after enzyme immobilization by polyaldehyde pullulan and glutaraldehyde was 1.83 and 0.41 mg/10 glass beads, respectively. Optimum pH and temperature for pectinase immobilized by both cross-linkers were 5.5 and 50 degrees C, and the specific activity under these conditions was 2.21 +/- 0.18 and 2.56 +/- 0.12 unit/mg for enzyme immobilized by polyaldehyde pullulan and glutaraldehyde, respectively. pH stability of the pectinase immobilized by polyaldehyde pullulan was higher than by glutaraldehyde, while both immobilized system has an almost similar temperature stability. The kinetic parameters were determined for both immobilization systems. Also, SEM and atomic force microscopy confirmed the presence of polyaldehyde pullulan on glass bead after immobilization. Eventually, the obtained results suggested that polyaldehyde pullulan can be applied as a high potential alternative to glutaraldehyde for the enzyme immobilization.

Automated summary

In this study, pectinase was immobilized on glass beads using two different cross-linkers: polyaldehyde pullulan and glutaraldehyde. The polyaldehyde pullulan showed better immobilization efficiency and stability compared to glutaraldehyde, while both systems exhibited similar temperature stability. The results suggest that polyaldehyde pullulan could be a promising alternative to glutaraldehyde for enzyme immobilization.