Electrospinning As a Tool for Enzyme Immobilization

Enzyme immobilization (covalent or noncovalent) on solid supports such as nanomaterials, resins or polymers can enhance the enzyme activity-, and selectivity, improving their stability. The present research is focused on the non-covalent immobilization of lipase B from Candida antarctica (CaL-B) into polyvinyl alcohol (PVA) nanofibers via electrospinning with the aim to prepare a stable and reusable biocatalyst compatible with organic reaction media. Polymer solutions of 8, 10 and 12 w/w % concentrations were used to investigate the effect of the polymer concentration on the biocatalyst’s activity. The immobilized enzyme amount was determined using the Bradford assay, while structural characterization was performed by transmission electron microscopy. The immobilized enzyme preparates were tested in the enzymatic kinetic resolution of (rac)-1-phenylethanol and its halogenated derivatives through transesterification with vinyl acetate in batch mode. The highest conversion was obtained in case of CaL-B entrapped in electrospun nanofibers prepared from 10 w/w % PVA solution (noted as 10%–PVA–CaL-B) and its high stability was confirmed in recycling experiments. It was found that after the 5th cycle the biocatalyst maintained 88% of its initial activity.