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Improved catalytic properties of Candida antarctica lipase B multi-attached on tailor-made hydrophobic silica containing octyl and multifunctional amino- glutaraldehyde spacer arms

2016; Elsevier BV; Volume: 51; Issue: 12 Linguagem: Inglês

10.1016/j.procbio.2016.09.016

1873-3298

Vinicius Vescovi, Willian Kopp, José M. Guisán, Raquel L. C. Giordano, Adriano A. Méndes, Paulo Waldir Tardioli,

Electrochemical sensors and biosensors

This work evaluated the immobilization of Candida antarctica lipase B (CALB) on a new heterofunctional support, prepared by silanization of silica particles with triethoxy(octyl)silane and trietoxy(3-aminopropyl)silane, followed by activation with glutaraldehyde. The new support (octyl-silica-amino-glutaraldehyde, OSGlu) exhibits features of an anionic exchanger and hydrophobic adsorbent capable of adsorbing and covalently linking the lipase under mild conditions in a single step. As comparison, CALB was also immobilized on silica coated with octyl, amino-glutaraldehyde, octyl and glyoxyl, and octyl and epoxy groups. Among these supports, CALB immobilized on OSGlu (namely CALB-OSGlu), showed the highest recovered activity (71 ± 2%) and thermal stability in tert-butyl alcohol (full activity was recovered after 100 h at 65 °C). CALB immobilized on silica coated with octyl or amino-glutaraldehyde yielded biocatalysts with lower recovered activities, compared to CALB-OSGlu, with values of 43% and 32%, respectively. CALB-OSGlu was chosen to be evaluated in the synthesis of fructose oleate in tert-butyl alcohol medium and at high temperature, achieving conversions above 70% in nine 6 h-cycles at 55 °C. CALB-OSGlu showed better operational stability than benchmark immobilized CALB (Novozym 435) in the same reaction conditions, with the conversion of the later decreasing from 84% (first cycle) to 53% (ninth cycle).