Abstract: The invention relates to a heterogenous enzymatic catalyst that takes the form of a cellular monolith consisting of a silica or organically modified silica matrix, said monolith including macropores, mesopores, and micropores, said pores being interconnected, and wherein the inner surface of the macropores is functionalized by a coupling agent selected from among silanes, said inner surface moreover having an unpurified enzyme attached thereon by means of a covalent or electrostatic bond.