Enhancing the catalytic performance of Candida antarctica Lipase B by immobilization onto the ionic liquids modified SBA-15

Abstract

In this study, mesoporous silica SBA-15 was modified by imidazole based ionic liquids (IL) with three different side-chain length of cations and two different anions. Prepared supports (IL-SBA-15) were 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 were evaluated, and the catalytic selectivity towards diacylglycerols (DAG) production in glycerolysis of triacylglycerols (TAG) reaction was also studied. Compared with the parent SBA-15 immobilized CALB (SBA-15-CALB), the IL modification gave a maximum improvement of enzymatic activity from 1855 to 5044 U/g; in addition, the selectivity towards the diacylglycerols (DAG) production was also increased, with the DAG/MAG ratio increasing from 3.72 to 11.99, and the DAG content increasing from 53.6 to 67.2 wt%.

Practical applications: Immobilization of lipases facilitates the separation of products and the recovery of lipases for reuse. The present study showed that CALB immobilized on the IL modified SBA-15 was potential for DAG production through glycerolysis, due to its considerable reusability as well as its high glycerolysis activity and selectivity towards DAG production, it could be considered for practical applications.

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