Study On Immobilization Of Lipase And Its Application

The immobilization of Lipase, its catalytic characteristics in organic solvent, the synthesis of isooctyl palmitate (IOP) by immobilized Lipase were studied.Main points are as follows:1. Immobilization of Lipase: The immobilization of Lipase (Lipolase 100L) with ion exchange resin by ion exchange adsorption was studied. The adsorption capacity of the enzymes on the ion exchanger was measured by Bradford method. The conditions for the immobilization were investigated. The results showed that the most of enzyme was immobilized when 1.5mL liquid lipase was added into one gram of pretreated resin, stirred for 10 hours at 35℃in buffer of pH10.There are numerous advantages of conducting enzymatic conversions in organic solvents over in water. The catalytic behaviors were investigated,including the influence of temperature, the dosage of immobilized Lipase ,water content ,organic solvent and the ratio of lauric acid to lauryl alcohol. It was found that the yield of the ester reached 91.3% when the ratio of lauric acid to lauryl alcohol was 0.2:0.2 (mol/L), the dosage of immobilized Lipase was 200mg in 50ml isooctane at 8% of water content and at 55℃after 210min in which obtained Ea is 19.00kJ/mol. The optimal ratio of acid to alcohol is 1:2.After two months reserved in 4℃,the residual activity of immobilized Lipase was still high.2. Study of the continues catalytic characteristics of immobilized Lipase in organic solvent : According to the characteristics of prepared immobilized Lipase and support ,simple PBR bio-reactor was applied in catalysis of esterification. Speed of substrate and catalyst loading were studied. When the concentration of substrate was 0.4mol/L, the optimal speed of substrate and catalyst loading were 10mL/h and 6g respectively. After being reused for 60 cycles , the remaining activity of immobilized Lipase was still about 89.82%.3. Application of immobilized Lipase in the continues synthesis of isooctyl palmitate: The results showed that it can be applied successful in the synthesis of IOP at the optimal ratio of acid to alcohol (1:1.5) and reaction temperature at 40℃. The yield of the ester reached 97.91% by gas chromatography.