Lipase B of Candida antarctica Co-adsorbed with Polyols onto TiO2 Nanoparticles for Improved Biocatalytic Performance

CARLOS R. LLERENA-SUSTER; MARIA VICTORIA TOLEDO; ANTONELA FITTIPALDI; SUSANA MORCELLE DEL VALLE; LAURA E. BRIAND

JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY

JOHN WILEY & SONS LTD

Lugar: Londres; Año: 2017 vol. 92 p. 2870 - 2880

0268-2575

BACKGROUND The immobilization of the lipase B of Candida antarctica CALB over TiO2 nanoparticles was thoroughly investigated with the isotherms of adsorption at various temperatures with and without the addition of sorbitol and glycerol. The surface composition, secondary structure and the effect of the addition of the polyols was addressed.RESULTS The maximum dispersion limit of protein on TiO2 NPs is 0.073 ± 0.007 mol.m-2. Glycerol and sorbitol co-adsorb on the TiO2 NPs reaching 45 % of the surface composition of the biocatalyst. The optimized material was able to catalyze the esterification of 52 % of R/S-ibuprofen with ethanol (0.31 ± 0.01 mol.min-1.mg-1) with 41 % of enantiomeric excess towards S(+)-ibuprofen in 24 hs of reaction. Under similar reaction conditions, the commercial counterpart Novozym® 435 showed 34 % of conversion (0.091 ± 0.003 mol.min-1.mg-1) and 16 % of enantiomeric excess.CONCLUSIONS The molecular association between the protein and the polyols exerts a positive cooperativism since prevents the aggregation of the protein and protects its active conformation. The residual esterase activity of the immobilized CALB compared with the free lipase depends directly on the amount of co-adsorbed polyols. Moreover, polyols boost the catalytic performance in the kinetic resolution of racemic ibuprofen showing an optimum at the maximum coverage of polyols on the biocatalysts.