Optimization of Immobilization Conditions of Candida antarctica Lipase Based on Response Surface Methodology

The conditions, including mass ratio of PEG4000 to lipase, pH, and mass ratio of diatomites to lipase, for immobilization of Candida antarctica lipase with PEG non-covalent modification were optimized by means of the response surface methodology (RSM). The immobilized lipase specific activity in the reaction of transesterification was selected as the response value. A mathematical model was developed to investigate the influences of various immobilization parameters and to predict the optimum immobilization conditions for lipase. The maximal specific activity was predicted to occur when PEG4000: lipase (w/w) was 7.61, diatomites: lipase (w/w), 9.92 and pH, 7.52, respectively. A repeat immobilization experiment of lipase was carried out under the optimized conditions for the verification of optimization. The maximal specific activity obtained experimentally was 56.11 U mg pr., which was significantly higher than that obtained under unoptimized conditions.