Abstract:

The (3-aminopropyl)trimethoxysilane and amine functionalized ionic liquid modified mesoporous silica SBA-15(NH₂-SBA, NH₂-IL-SBA) were synthesized, and NH₂-IL-SBA was activated by glutaraldehyde(CA-NH₂-IL-SBA). Physical and chemical properties of the materials were characterized by elemental analysis, nitrogen adsorption-desorption, small-angle X-ray diffraction and Fourier transform infrared spectroscopy. The prepared materials were used as novel carrier systems to immobilize Burkholderia cepacia lipase(BCL) by physical adsorption, conventional covalent attachment and enzyme-aggregate coating methods. Enzymatic properties, including activity, optimum reaction condition and stability were investigated in the triacetin hydrolysis reaction. The results showed that the modification and activation did not destroy the structure of SBA-15. Compared with the immobilized BCL on NH₂-SBA and parent SBA-15(BCL-NH₂-SBA, BCL-SBA-15), the immobilized BCL on novel carriers were more resistant to temperature and low pH changes and possessed both higher activity and stability. Especially, the BCL prepared by enzyme-aggregate coating method exhibited highest immobilization efficiency and stability, which improved 4.0 and 2.0 folds of thermal stability and reusability than BCL-SBA-15, respectively.

Key words: Burkholderia cepacia lipase, Ionic liquid, Mesoporous material, Modification, Immobilization