IMOBILISASI LIPASE PADA CHITOSAN BEAD DENGAN TEKNIK PENGIKATAN SILANG : PENGARUH pH DAN KONSENTRASI KITOSAN TERHADAP AKTIVITAS TRANSESTERASE

• Main Authors: , SUSAN PRIMADEVI, , Dr. Tri Joko Raharjo, M.Si.
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2013
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/119442/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=59444
• Institution: Universitas Gadjah Mada

Effects of pH and chitosan concentration for immobilization lipase on chitosan bead by crosslinking technique has been carried out. The study was aimed to determine the optimum conditions for immobilization process. Chitosan was prepared from crab shell by No and Meyer methode (1989), then was modified into chitosan bead through swelled process. The beads were crosslinked using glutaraldehyde. Immobilization of lipase on the crosslinked chitosan beads was performed under the optimum conditions such as solubility pH of lipase and concentration of chitosan. Immobilized and free lipases were assayed its activity, thermal stability, repeated usage stability and kinetic parameters with transesterification reaction of palm oil using methanol. The optimum conditions of immobilization were achieved when lipase was dissolved in phosphate buffer at pH 6 and concentration of chitosan was 5%. Transesterase activity of the immobilized lipase decreased 20-40%, while activity of free lipase decreased 30-45% at the preheating temperature 35-45 °C. The largest decrease of immobilized lipase and free lipase activity occured at temperature of 45-50 oC with the value of decreasing were 51.81% and 97.29%. Immobilized and free lipases could be used for two reaction cycles with decreased activity of 72.40% and 56.29%. Affinity of enzyme on the substrate was shown by KM value. KM value of immobilized and free lipases were 0.800 and 0.081, respectively. Immobilized lipase has better thermal stability but has lower reuse stability and affinity than the free lipase.