Immobilized cell and preparation method thereof

A method of immobilizing cells containing lysine decarboxylase comprising the steps of:

• a) dissolving a first synthetic macromolecule material in an aqueous solution sufficiently;
• b) adding cells to be immobilized which contain lysine dacarboxylase into the resulting solution and immobilizing said cells,
• wherein the first synthetic macromolecule material is any synthetic macromolecule material having a gel-forming ability, and the immobilization is carried out under conditions that do not destroy the viability of said cells containing lysine decarboxylase.