RESUMEN
In this study, the modulation of enzymatic biocatalysts were developed by the use of lipase B from Candida antarctica covalently immobilized on an eco-friendly support, cashew apple bagasse, activated with 10% glycidol-ethylenediamine-glutaraldehyde (GEG) under different immobilization strategies (5 mM or 100 mM ionic strength and in absence or presence of 0.5% (v/v) Triton X-100). The biocatalysts were characterized for thermal and organic solvents stabilities and compared with the soluble enzyme. The biocatalysts were then applied to the hydrolysis of the rac-indanyl acetate (2:1 ratio enzyme/substrate) at pH 7.0 and 30 °C for 24 h. For all the strategies evaluated, GEG promoted kinetic resolution of rac-indanyl acetate with maximum conversion (50%) and led to (R)-indanol with excellent enantiomeric excess (97%), maintaining the maximum conversion for five consecutive cycles of hydrolysis. Therefore, the use of cashew apple bagasse has proved to be a promising eco-friendly support for enzyme immobilization, since it resulted in stable biocatalysts for enzymatic kinetic resolution.
Asunto(s)
Acetatos/química , Basidiomycota/enzimología , Proteínas Fúngicas/química , Lipasa/química , Anacardium/metabolismo , Candida/enzimología , Estabilidad de Enzimas , Enzimas Inmovilizadas/química , Etilenodiaminas/química , Glutaral/química , Concentración de Iones de Hidrógeno , Cinética , Bases de Schiff , Solventes/química , Estereoisomerismo , Temperatura , Factores de TiempoRESUMEN
In this communication, lipase A from Candida antarctica (CALA) was immobilized by covalent bonding on magnetic nanoparticles coated with chitosan and activated with glutaraldehyde, labelled CALA-MNP, (immobilization parameters: 84.1% ± 1.0 for immobilization yield and 208.0 ± 3.0 U/g ± 1.1 for derivative activity). CALA-MNP biocatalyst was characterized by X-ray Powder Diffraction (XRPD), Fourier Transform Infrared (FTIR) spectroscopy, Thermogravimetry (TG) and Scanning Electron Microscope (SEM), proving the incorporation of magnetite and the immobilization of CALA in the chitosan matrix. Besides, the immobilized biocatalyst showed a half-life 8-11 times higher than that of the soluble enzyme at pH 5-9. CALA showed the highest activity at pH 7, while CALA-MNP presented the highest activity at pH 10. The immobilized enzyme was more active than the free enzyme at all studied pH values, except pH 7.