Immobilization Of Lipase And Its Characterization

In this paper, the immobilization method of lipase on canvas fiber and its stability were discussed. NaIO4 was employed to oxidate the adjacent hydroxyl into aldehyde group. The cross-link experiments showed that the lipase density on the carrier surface could be raised 30% by using repeat cross-link comparing with one-off cross-link. The hydrolysis activity of the immobilized lipase also agreed well with the above results. Compared with the free lipase, the stability of immobilized lipase to pH and temperature had been raised in some degree. The hydrolysis of soybean oil by immobilized lipase showed that 64% of relative activity of lipase was still kept after 7 batches reaction. The half-life of the immobilized lipase is longer than 140 hours.Hollow fiber is also studied for immobilization by filling the lipase solution to the lumen space. The result showes that the hydrolysis can reach 90% in 50 hours at mild reaction conditions. It is easy to separate the product for its fine quality, 90% activity was kept after 5 batches of hydrolysis.On the basis of lipase immobilization, we studied the enzyme reactor for transesterification between soybean oil and methanol. The optimum condition for reactor was got by confirming the effects of ratio of substrate ingredient, water content, adding style of methanol. It can reach an 86% transesterification in 30 hours at the simple designed reactor. It kept a high catalyst activity after 12 batches reaction. The methanol alternatives (methyl acetate And ethylic acetate) were used to carry out the transesterification between soybean oil and ester. In this paper, some results were got by controlling the reaction conditions, but the low efficiency was still needed to study.