IMOBILISASI LIPASE DENGAN TEKNIK TAUT SILANG PADA KITOSAN SERBUK DAN UJI AKTIVITAS HIDROLISISNYA TERHADAP MINYAK KELAPA SAWIT; IMOBILIZATION OF LIPASE VIA CROSS LINKING TECHNIQUE ON CHITOSAN POWDER AND HYDROLYSIS ACTIVITY ASSAY OF PALM OIL

Fandhi Adi Wardoyo, Tri Joko Raharjo

2013 | Disertasi | PROGRAM STUDI S2 ILMU KIMIA

Immobilization of lipase on chitosan powder was performed via cross linking technique. The aim of this research is to determine the optimum conditions for the immobilization process. Chitosan was prepared from crab shell through continous deacetylation, and crosslinked with glutaraldehyde. Immobilization of lipase on chitosan powder was studied under the optimum conditions e.i. pH optimum of lipase solubility and mole ratio of chitosan:glutaraldehyde. Immobilized lipase on chitosan powder was tested for the activity, thermal stability, multiple-use stability and kinetic parameters through the hydrolysis reaction of palm oil. Continous deacetylation produced chitosans A, B and C with deacetylation degrees of 81.34% , 90.23%, and 92.80%, respectively. The optimum pH for enzyme dissolution was obtained at pH 6. Mole ratio of chitosan:glutaraldehyde for the enzyme immobilization reached optimum condition at a ratio of 2:1. Optimum efficiency of immobilization on chitosans A, B, and C, were 53.01; 43.84 and 40.21%, respectively. Specific activity of free lipase, immobilized lipase on chitosan A, immobilized lipase on chitosan B and immobilized lipase on chitosan C were 23.94; 0.0472; 0.0151; and 0.0144 U/g, respectively. Immobilized lipase was able to maintain its activity at 50 °C. The immobilized lipase was also able to maintain its activity after multiple-uses up to five reaction cycles. Affinity of lipase immobilized on the substrate was decreased than free lipase.

Kata Kunci : lipase; imobilisasi; kitosan; taut silang; hidrolisis