Abstract: There is disclosed a process for isomerization of glucose into fructose which comprises contacting an aqueous glucose solution with glucose isomerase in the presence of iron ion and magnesium ion, said glucose isomerase being in the form of insolubilized glucose isomerase adsorbed on a carrier.

Abstract: A method for extracting and collecting kallidinogenase (EC 3.4.4.21 substance) which comprises extracting the pancreas of a mammal with water in the presence of a salt at a temperature of about 45.degree. to about 60.degree. C. and a pH of about 5 to about 8, wherein the extraction is carried out in the presence of a water-soluble salt of magnesium with an acid, and a method for purifying kallidinogenase which comprises subjecting the aqueous phase of a kallidinogenase-containing aqueous extract obtained from the pancreas of a mammal to an adsorption-elution treatment using an anion-exchange resin, wherein said aqueous phase of the kallidinogenase-containing aqueous extract is brought into contact with a gel-type weakly basic anion-exchange resin to cause the kallidinogenase fraction to be adsorbed to said resin, and the kallidinogenase is eluted with an aqueous solution of an ammonium salt of a weak acid, thereby to collect the kallidinogenase.