Application and properties of siliceous mesostructured cellular foams as enzymes carriers to obtain efficient biocatalysts

The application of siliceous mesostructured cellular foams (MCF) with the surface functionalised using different organosilanes to immobilize covalently invertase and glucoamylase have been studied. Four organosilanes were applied: 3-aminopropyltriethoxysilane (APTS), 2-aminoethyl-3-aminopropylmethyldimethoxysilane (AEAPMDS), 2-aminoethyl-3-aminopropyltrimethoxysilane (AEAPTS) and 3-glicydoxypropyl-triethoxysilane (GPTS). The samples modified using alkylamines were further functionalised with glutaraldehyde (GLA), a cross linker. Commercially available silica gels and Eupergit C were used for comparison. Activity of MCF-based biocatalysts was significantly higher than of the silica gel and Eupergit C based counterparts. In the best systems the determined activity of both immobilized enzymes was even higher than that of the free enzymes. The glutaraldehyde (GLA)-amino linkage formed by organosilanes with two amino groups was the most effective system for MCF-bound invertase and that formed by APTS in the covalent immobilization of glucoamylase. A unique porous structure of MCF was found to be a critical factor which renders siliceous mesostructured foam a very promising material for immobilization of enzymes.