GLYCERIDE SYNTHESIS USING LIPASE IMMOBILIZED IN N-POLYISOPROPYLACRYLAMIDE GEL

Lipase from Candida cylindracea was immobilized in the gel beads prepa red by copolymerization of N-isopropylacrylamide, N,N'-methylenebisacr ylamide, and acrylamide. The optimal conditions of immobilization of l ipase, for example molar ratio of monomer, cross-linking reagent, poly merization initiator, and stirring speed, are investigated. The esteri fication reaction between oleic acid and glycerol was carried out at 3 7 degrees C by using the immobilized lipase or free lipase. It is foun d that selectivity of monoolein synthesis is higher when using immobil ized lipase in gels compared with free lipase. The gel beads undergo t hermal phase transition. The gel swells below lower critical solution temperature (LCST) and shrinks above LCST. An esterification reaction by lipase immobilized in gel was carried out by swinging the temperatu re between 37 degrees C (above LCST) and 5 degrees C (below LCST). It is found that the mass transfer rate in the gel is enhanced by phase t ransition.