Entrapment of lipases in hydrophobic magnetite-containing sol-gel materials: magnetic separation of heterogeneous biocatalysts

The simultaneous entrapment of a lipase such as Pseudomonas cepacia or Candida antarctica and nanostructured superparamagnetic magnetite (Fe3O4) in hydrophobic sol-gel materials derived from CH3Si(OCH3)(3) (MTMOS) or other hydrophobic precursors leads to catalytically active, mechanically stable and magnetically separable heterogeneous biocatalysts. The relative enzyme activity in the test reaction involving the esterification of lauric acid by n-octanol in isooctane is typically 200-300%, with respect to the same reaction using a conventional suspension of the non-immobilized enzyme. Separation of the catalyst by applying a simple magnet poses no problems. In the kinetic resolution of 2-pentylamine, enantioselectivity is essentially complete (ee = 97-99%). (C) 1998 Elsevier Science B.V. All rights reserved.