Enzyme-containing polymers are prepared by an anhydrous process of direct reaction of an enzyme in organic solution with crosslinking organic compounds having terminal reactive groups. In a first step, the enzyme is reacted in an organic solvent with a bifunctional monomer such as p-phenylene diisocyanate, 4-methyl-m-phenylene diisocyanate or 4,4′-methylenebisphenyl diisocyanate, and in a second step a bifunctional amine such as N-phenylethylenediamine, 1,6-diaminohexane, N,N′-diethyl-ethylenediamine or 1,4-diaminobutane is added. The enzyme-containing polymers are used as catalysts in chemical reactions such as acylation or enantioselective acylation of alcohols.