The Immobilization And Application Of Ocean Lipase YS2071

Lipase is a kind of important hydrolase,widely exists in animals,plants and microbes.However,the research of the lipase started late in our country compared with foreign,especially in ocean lipase.Lipase can catalytic esterification,transesterification,hydrolysis,alcoholysis and various chemical reactions and be used in food processing,medicine,environmental protection and so on.However,free lipase is expensive and difficult to achieve continuous operation,which limits the application of lipase.In order to improve the efficiency of lipase utilization and better applied to industrial production,we established an immobilization method of lipase YS2071 by screening the carrier,optimizing the immobilization conditions and studied enzymatic properties.At last,we applied immobilized enzyme to the biodiesel conversion.The results of the study are as follows:Preparation immobilized enzyme: Screening 11 kinds of resin carrier and comparing the activity of immobilized enzyme,the recovery of enzyme activity and protein adsorption rate to determine the MI-BSI functional adsorption resin as the optimal carrier.Immobilized conditions were studied by using single factor,PB experiment and the response surface design.The conditions of immobilized lipase were optimized by analyzing the enzyme dosage,adsorption time,temperature,initial pH,concentration of crosslinking agent,crosslinking time with geniping as crosslinking agent and adsorption-crosslinking method.The optimal conditions of immobilized lipase YS2071 were:the enzyme dosage was 2 mg/mL,the adsorption time was 8 h,the temperature was 20 ?,the initial pH was 8.6,the concentration of genipin was 0.48 g/L,the crosslinking time was 1 h.On this condition,the maximum activity and recovery rate of immobilized enzyme was up to 936.71 U/g and63%,respectively.Enzymatic properties: Compared with the free enzyme and immobilized enzyme properties,respectively.The results showed that the optimum temperature offree enzyme and immobilized enzyme were 40 ?,the optimum pH was 9.The thermal stability,pH stability,tolerance of metal ions and organic solvents of immobilized enzyme has improved significantly.The activity of the immobilized enzyme still retain 65%,but 34% of free enzyme after 30 d.After repeated use 10 times,the residual enzyme activity of immobilized enzyme remains at 32%.Biodiesel conversion: Analyzing the standard and conversion product by using thin layer chromatography(TLC)and HPLC and determining the mobile phase was the acetone:acetonitrile = 64:36(V/V).Translation of rice germ oil,corn oil,sunflower oil to study the ethyl ester conversion by analyzing enzyme dosage,water content,alcohol oil ratio,temperature and reaction time.The study showed that the efficiency of ethyl ester conversion of rice germ oil was the highest,and then optimize the conversion conditions by orthogonal experiment.The optimal conditions of ethyl ester conversion of rice germ oil:enzymatic dosage was 40 mg/mL,water content was0.125%,temperature was 40 ?,alcohol oil ratio was 4:1,conversion time was 30 h.Under the optimal conditions,the conversion rate was 43.8%.