Sur la compacit du spectre minimal d''''un anneau

Immobilizates of acylases (N-acyl-L-amino acid amidohydrolases) are prepared by binding the acylase to a carrier by reacting the acylase with a chemically bound reactive group of a cellulose derivative. The cellulose derivative is prepared by reaction of a hydroxyl group of cellulose with a reagent containing at least two reactive functional groups to provide the reactive group. The reaction of a hydroxyl group of cellulose and reagent is performed by contacting the reagent with cellulose dissolved in dimethylsulfoxide containing polyhydroxymethylene for reaction of the cellulose and reagent to form said derivative.