OPTIMASI IMOBILISASI LIPASE PADA KITOSAN BEAD DENGAN TEKNIK TAUT SILANG DAN STUDI PENGGUNAANNYA SEBAGAI BIOKATALIS REAKSI TRANSESTERIFIKASI DALAM SISTEM PELARUT t-BUTANOL; OPTIMIZATION OF LIPASE IMMOBILIZATION ON CHITOSAN BEAD WITH CROSSLINKING TECHNIQUE AND ITS APPLICATION STUDY AS BIOCATALYST OF TRANSESTERIFICATION IN t-BUTANOL SOLVENT

Khasanah, Sabtun I, Tri Joko Raharjo

2015 | Disertasi | FMIPA

Optimization of lipase immobilization on chitosan bead with crosslinking technique and study its application as biocatalyst of transesterification in hydrophilic solvent has been done. The research objectives were to study the optimum conditions of immobilization, to study the solvent effect used in the reaction and to study the use of the immobilized lipase as a biocatalyst in transesterification. The research was begun with isolation of chitosan from crab shell then chitosan be modified into chitosan beads through swelling process. Chitosan beads cross-linked with glutaraldehyde and lipase. Optimization of enzyme concentration and immobilization time was taken to obtain the optimum immobilization. The immobilized enzyme was used as catalyst in transesterification reaction using n-hexane and t-butanol solvents. Then, optimization of transesterification conditions in t-butanol solvent, include the effect of ratio methanol:oil and adding water concentration in reaction Ammount of methyl ester converted was determined by GC analysis. Optimum conditions of immobilization were shown in adding free lipase 4% (w/v) in buffer pH 6 and immobilization time was 100 minutes, the immobilization efficiency was 61.35%. Transesterification reaction in t-butanol solvent has result methyl ester larger than in n-heksan solvent, the result respectively 3,31% and 2,93%. Optimum conditions of tranesterification reaction were shown in reaction with ratio of methanol:oil 4:1 and 3% of water concentration. In this condition, Ammount of methyl ester converted was 4,65%.

Kata Kunci : immobilization; chitosan bead; lipase; t-butanol; transesterification