Mesoporous silicas with tunable morphology for the immobilization of laccase

Open Access

Abstract

Siliceous ordered mesoporous materials (OMM) are gaining interest as supports for enzyme immobilization due to their uniform pore size, large surface area, tunable pore network and the introduction of organic components to mesoporous structure. We used SBA-15 type silica materials, which exhibit a regular 2D hexagonal packing of cylindrical mesopores of uniform size, for non-covalent immobilization of laccase. Synthesis conditions were adjusted in order to obtain supports with different particle shape, where those with shorter channels had higher loading capacity. Despite the similar isoelectric points of silica and laccase and the close match between the size of laccase and the pore dimensions of these SBA-15 materials, immobilization was achieved with very low leaching. Surface modification of macro-/mesoporous amorphous silica by grafting of amine moieties was proved to significantly increase the isoelectric point of this support and improve the immobilization yield. © 2014 by the authors. ; The authors thank the Spanish Government for financial support through the project MAT 2012-31127, and Ramiro Martinez (Novozymes, Spain) for his kind help with the supply of laccase. V. G. acknowledges Ministerio de Educación, Cultura y Deporte for a FPU PhD fellowship. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI) ; Peer Reviewed