Studies on Immobilization of Cutinases from Thermobifida fusca on Glutaraldehyde Activated Chitosan Beads

Abstract

Aims: To evaluate and optimize the activity and stability performance of two recombinant cutinases of Thermobifida fusca, Cut1 and Cut2 on glutaraldehyde activated chitosan beads. Place and Duration of Study: Biochemical Engineering Laboratory, Department of Biotechnology, Indian Institute of Technology Guwahati, Assam India. Experiment conducted as a partial fulfillment to PhD degree from December, 2010 to January, 2014. Methodology: Purified cutinase were immobilized on chitosan beads by covalently coupling with glutaraldehyde. The biophysical properties of immobilized cutinase was Original Research Article British Biotechnology Journal, 4(10): 1049-1063, 2014 1050 analysed by FTIR, FESEM and the operational stability and activity of the immobilized cutinase was studied at different pH and temperature. Results: The optimal immobilization was achieved with 3% (v/v) glutaraldehyde activation and coupling pH of 8.5. Under this condition, 74% and 71% of immobilization was achieved for Cut1 and Cut2, respectively. Immobilized cutinase showed optimal activity at pH 8 with optimal functional range of pH 7.5 to 9 and 55oC with operational stability in the range of 45oC to 70oC. The reusability and storage stability was found to be 80% after 10 reuse cycles and 50% after 13 days, respectively as compared to its initial activity. There was no loss in activity even after repeated freeze drying. Conclusion: the cutinase immobilized on glutaraldehyde activated chitosan beads demonstrated better operational stability in comparison to free cutinase, showing chitosan as a potential support in the enzyme immobilization technology for industrial applications of T. fusca cutinases.