Influence of Varying Surface Hydrophobicity of Chitosan Membranes on the Adsorption and Activity of Lipase

摘要

The hydrophobic surface modification ofchitosan membranes was performed using the amidatingreaction of amino groups on a membrane surface withstearic acid activated by 1-ethyl-3-(3-dimethylamino-propyl)-carbodiimide hydrochloride (EDC) and N-hydrox-ysuccinimide (NHS). The varying surface hydrophobicityof chitosan membranes was achieved by changing thedegree of amidation and evaluated by the water contactangle analysis and the adsorption experiment of thehydrophobic dye, Rose Bengal. The effects of the surfacehydrophobicity of chitosan membranes on the adsorptionbehaviors, activity and stability of Candida rugosa lipases were investigated. The experimental results suggestedthat the increased surface hydrophobicity of chitosanmembranes improved the adsorption capacity and activ-ity of the immobilized lipase. The modified chitosanmembranes with 30.36% amidation exhibited the maxi-mum activity retention of 83.87%. In addition, a desirablethermal stability was also achieved for the adsorbed lipase.