Effect of Anion and Amino Functional Group on Resin for Lipase Immobilization with Adsorption-Cross Linking Method

Lipase is one of biocatalysts which have been used commercially for processes in industries, such as bioenergy, food, and pharmaceutical industry. Nowadays, biocatalysts are preferred in industries because they work in mild condition, have high specificity, and reduce energy consumption (high pressure and temperature). But, the usage of lipase for industrial scale is limited by economic reason due to expensive price of lipase and difficulty of separation system. Immobilization of lipase is one of the solution to maintain activity of lipase and reduce separation system in process. Therefore, we conduct study about lipase immobilization with adsorption-cross linking method using glutaraldehyde because this method produce high enzyme loading and stability. Lipase is immobilized on different kind of resin with various functional group. Highest enzyme loading (76.69%) was achieved by lipase immobilized on anion macroporous resin which have anion functional group (OH- ). However, highest activity (24,69 U/g support) through olive oil emulsion method was achived by lipase immobilized on anion macroporous-chitosan which have amino (NH2 ) and anion (OH- ) functional group. In addition, it also successed to produce biodiesel with yield reaching 50,6% through interesterification reaction and after 4 cycles it still produced a yield of 63.9% relative to initial yield. Meanwhile, for Aspergillus niger lipase immobilized on anion macroporous chitosan is show unit activity of 22,84 U/g resin and biodiesel yield higher than commercial lipase (69,1%) and after 4 cycles it is still stable reach 70.6% relative from initial yield. This shows that optimum functional group on support for immobilization with adsorption-cross linking is support that contains amino (NH2 ) and anion (OH- ) functional groups because they can react with glutaraldehyde and bind with enzyme, therefore preventing the desorption of lipase from support through binding lipase with functional group on support.