Enhancing the Catalytic Performance of Candida antarctica Lipase B by Immobilization onto the Ionic Liquids Modified SBA-15

In this study, mesoporous silica SBA-15 is modified by imidazole based ionic liquids (IL) with three different side-chain length of cations and two different anions. Prepared supports (IL-SBA-15) are characterized by small-angle powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) as well as Fourier transform infrared (FT-IR), and then used to immobilize Candida antarctica lipase B (CALB). The enzymatic properties of the obtained IL-SBA-15-CALB are evaluated, and the catalytic selectivity toward diacylglycerols (DAG) production in glycerolysis of triacylglycerols (TAG) reaction is also studied. Compared with the parent SBA-15 immobilized CALB (SBA-15-CALB), the IL modification gives a maximum improvement of enzymatic activity from 1855 to 5044 U g(-1); in addition, the selectivity toward the diacylglycerols (DAG) production also increases, with the DAG/MAG ratio increasing from 3.72 to 11.99, and the DAG content increasing from 53.6 to 67.2 wt%.