Immobilisation of enzymes on mesoporous silicate materials

Abstract

Mesoproous silicates (MPS) are attractive materials for the immobilisation of enzymes. They possess 5 ordered pore structures, narrow pore size distributions, large surface areas, high stability and can be chemically modified with various functional groups. The properties of MPS materials are reviewed in terms of their ability to act as supports for enzymes for use in biocatalysis with a particular focus on the ability to tailor the surface functionalization of the MPS to suit a specific enzyme. While many reports of the immobilisation of enzymes on MPS have been described, their use as biocatalytic supports is limited. 10Large scale reactors based on MPS will require continuous flow systems where the properties of the support can be tailored while allowing fluid flow at reasonable low pressure.

Comparison of mesoporous silicate supports for the immobilisation and activity of cytochrome c and lipase

“…As the pore diameters of both materials are larger than that of cytochrome c (ca. 4 nm) [30], these results clearly indicate that the amount of adsorbed protein is a reflection of the different surface areas, pore shapes and pore volumes of the two materials, parameters that are known to influence the loading of enzymes [6,34]. It is also likely that some blocking of the pores occurred, particularly with PPS which has a broader pore size distribution and a larger proportion of channels with smaller pore diameters.…”

“…A detailed description of the parameters that influence the adsorption of an enzyme on a porous support has been described [1,2,6]. These factors include the size of the enzyme, the pore diameter, pore size distribution and surface area of the silicate, pH, ionic strength, the isoelectric point, the hydrophilic/hydrophobic, nature of the enzyme, and the surface properties of the support.…”

Enzyme immobilization by adsorption: a review

“…By contrast, in mesoporous silica MCM-41 (Mobil Composition of Matter), with hexagonally ordered mesopores (Choma et al 2004;Weber et al 2010), the pore size is from 2 to 8 nm, which is controlled by adjusting the synthesis conditions and/or by applying surfactants with different chain lengths (pore sizes 2-5 nm) or expanders (pore sizes up to 8 nm) in their preparation. The pore volume in this silica is close to 1.0 cm 3 /g and its surface area exceeds 1,200 m 2 /g (Magner 2013), which are features that classify this material as a carrier for the enzyme immobilization. FDU-12 (Fudan University Material) (Hartono et al 2010) is another mesoporous silica material with face-centered cubic structures of spherical mesopores and surface area of about 700 m 2 /g, pore size from 10 to 15 nm and pore volume from 0.6 to 0.7 cm 3 /g.…”

“…Among many inorganic carriers used for immobilization of enzymes by adsorption, silicas are apparently those carriers, which have drawn most attention (Erhardt and Jordening 2007;Magner 2013;Hartmann and Kostrov 2013). Silicas of different dispersive-morphological parameters and porous structures have been proposed.…”

Immobilization of Amano Lipase A onto Stöber silica surface: process characterization and kinetic studies

“…The supports can be either synthetic materials (mainly silicas) [11,12] or natural ones such as chitin and chitosan [13][14][15]. They are also characterized by high stability, well-developed surface area, and the possibility of surface functionalization with many modifying compounds [16,17].…”