IMMOBILISASI LIPASE PADA KITOSAN BEAD MENGGUNAKAN ASAM SITRAT SEBAGAI PENAUT SILANG DAN UJI AKTIVITAS HIDROLISISNYA; IMMOBILIZATION OF LIPASE ON CHITOSAN BEAD USING CITRIC ACID AS CROSSLINKER AND ITS HYDROLYSIS ACTIVITY

DIAN NUGRAHENI, Tri Joko Raharjo

2015 | Disertasi | FMIPA

Immobilization of lipase on chitosan bead using citric acid as crosslinker and its hydrosysis activity have been investigated. The aims of this research are to confirm whether citric acid can be used as crosslinker on immobilization of lipase on chitosan bead and to observe thermal stability, reusability, and kinetic parameter of immobilized lipase in hydrolisis activity. Chitosan bead was made by dissolving chitosan powder into citric acid solution. Optimum concentration of citric acid and chitosan on bead, pH and time of lipase immobilization were determined by varying these variables. Thermal stability, reusability, and kinetic parameter of immobilized lipase were studied in hydrolysis activity and compared to those of free lipase. The result shows that pH 4 is the optimum pH for immobilization of lipase. Immobilized lipase has specific activity lower than that of free lipase, however thermal stability and reusability are higher than those of free lipase. Afinity of immobilized lipase towards substrate lower than that of free lipase as shown by values of KM and Vmaks . KM value of immobilized lipase and free lipase are 17.66 × 10-3 M and 9.80 × 10-3 M, respectively. Vmaks value of immobilized lipase is 8.98 × 10-3 M/min lower than that of free lipase which is 9.98 × 10-3 M/min.

Kata Kunci : immobilization; lipase; citric acid; chitosan bead; hydrolisis activity