Immobilization of Candida antarctica lipase B on kaolin and its application in synthesis of lipophilic antioxidants

Lipase B from Candida antarctica was immobilized by adsorption onto laboratory prepared metakaolin. This support has great potential for enzyme immobilization since it has good mechanical characteristics and thermal stability and it is easily obtained from naturally abundant raw kaolin, as presented in this paper. Immobilization process was studied as a function of pH, ionic strength and protein concentration in terms of immobilization and activity yield. It was shown that immobilization occurred via the Langmuir model, and that electrostatic forces were major, but not exclusive contributor for the binding process. The optimum conditions were achieved in 10 mM acetic buffer pH 5. Biocatalyst obtained under optimum conditions was further successfully used in the synthesis of lipophilic antioxidants, where conversion yields as high as 100% were achieved.