Preparation of d-fructose

A process for preparing D-fructose which comprises the steps of polymerizing N,N'-lower alkylene-bis-acryloyl-amide, bis(acryloylamidomethyl)ether or N,N'-di-acryloyl-ethyleneurea, or copolymerizing acryloylamide with N,N'-lower alkylene-bis-acryloylamide, bis(acryloylamidomethyl)ether or N,N'-di-acryloyl-ethyleneurea, in an aqueous suspension of a glucose isomerase-producing microorganism in the presence of a polymerization initiator and a polymerization accelerator to produce an immobilized glucose isomerase-producing microorganism, and subjecting the immobilized glucose isomerase-producing microorganism to enzymatic reaction with D-glucose in the presence of magnesium and cobaltous ions.

A process for preparing D-fructose which comprises the steps of polymerizing N,N'-lower alkylene-bis-acryloylamide, bis(acryloylamidomethyl)ether or N,N'-di-acryloyl-ethyleneurea in an aqueous suspension containing 0.25 to 2.5 g, per g of the acryloyl monomer, of a glucose isomerase-producing microorgansim in the presence of 1 to 100 mg, per g of the acryloyl monomer, of a polymerization initiator and 1 to 100 mg, per g of the acryloyl monomer, of a polymerization accelerator at 0.degree. to 50.degree. C, forming granules of the immobilized glucose isomerase-producing microorganism, and then subjecting said granules of the immobilized microorganism to enzymatic reaction with D-glucose at 20.degree. to 80.degree. C at a pH 6 to 9 in the presence of 1 to 20 millimoles of magnesium ion and 0.1 to 10 millimoles of cobaltous ion per liter of the reaction solution.

A process for preparing D-fructose which comprises the steps of copolymerizing acryloylamide with 5 to 160 mg, per g of acryloylamide, of N,N'-lower alkylene-bis-acryloylamide, bis(acryloylamidomethyl)ether or N,N'-di-acryloylethyleneurea in an aqueous suspension containing 0.25 to 2.5 g, per g of the acryloyl monomers, of a glucose isomerase-producing microorganism in the presence of 1 to 100 mg, per g of the acryloyl monomers, of a polymerization initiator and 1 to 100 mg, per g of the acryloyl monomers, of a polymerization accelerator at 0.degree. to 50.degree. C, forming granules of the immobilized glucose isomerase-producing microorganism, and then subjecting said granules of the immobilized microorganism to enzymatic reaction with D-glucose at 20.degree. to 80.degree. C at a pH 6 to 9 in the presence of 1 to 20 millimoles of magnesium ion and 0.1 to 10 millimoles of cobaltous ion per liter of the reaction solution.