Kali-chemie Aktiengesellschaft

Dirk Bonse

Guenter Weidenbach

Boris Meyer

Gunter Weidenbach

Hubert Schindler

Hans-Joerg Mueller

Enzymes are immboilized on an inorganic carrier which is a round, macropermeable agglomerate having a mulberry-type structure formed from spherical microporous .alpha.-aluminum oxide hydroxide particles. An organic polycondensate having free organic functional groups as enzyme binding sites penetrates the agglomerate. The .alpha.-aluminum oxide hydroxide particles of the agglomerate retain essentially their form prior to agglomeration. The polycondensate is prepared by reacting a polyimine with a dialdehyde or an epoxy compound. Preferably, the polyimine is polyethyleneimine, the dialdehyde is glutardialdehyde and the epoxy compound is an epoxy-functional silicon resin, an aliphatic diepoxide or an aliphatic triepoxide. The agglomerate is prepared by granulating the .alpha.-aluminum oxide hydroxide particles in the presence of the polyimine to form the agglomerate having the polyimine dispersed throughout and then reacting the polyimine with the dialdehyde or the epoxy compound. A preferred enzyme is glucose isomerase.

Enzyme immobilzation on a macropermable agglomerate of microporous .alpha.-

Disclosed is a process for the preparation of a solution containing glucose and fructose (isoglucose) by the conversion of a glucose-containing solution on a catalyst having glucose isomerase activity and produced on the basis of a SiO.sub.2 carrier. The productivity of the catalyst may be significantly increased by the addition of SiO.sub.2 to the glucose solution, and the catalyst according to the present invention is not damaged by temporary process shutdowns.

Process for the preparation of isoglucose

When isomerizing part of the glucose content of a glucose-containing solution to fructose, the productivity of glucose isomerase immobilized on an SiO.sub.2 carrier is increased considerably by pre-contacting the glucose-containing solution with particles of SiO.sub.2 or aluminum silicate. An apparatus is used having a reaction vessel containing the immobilized glucose isomerase and a pre-column containing the particles of SiO.sub.2 or aluminum silicate.

Process and apparatus for isomerizing glucose to fructose

Enzymes are covalently bonded to porous inorganic supports by a process wherein maximum activity of enzyme in the water-insoluble enzyme composition is achieved with the lowest possible amount of enzyme. The process involves selecting an inorganic carrier having a most frequent pore-diameter that results in highest enzymatic activity possible per weight unit of the insoluble enzyme composition at the given enzyme concentration within the insoluble enzyme composition, and contacting the selected inorganic carrier with an enzyme solution containing an amount of enzyme which is sufficiently low so that the enzyme in the insoluble enzyme composition has a specific activity which is substantially the same as that of the enzyme in solution in the free state.

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Arpke, Germany

Dirk Bonse