The gene(s) encoding enzyme(s) involved in the initial reaction during degradation of zearalenone was characterized from the zearalenone utilizer Pseudomonas putida strain ZEA-1, in which ZEA transformed into product with less or not toxic. A 5.5 kilobase-pair (kpb) Pst1-Kpn1 fragment containing gene(s) coding for zearalenone degradation was cloned. The cloned gene(s) activity was expressed in Escherichia coli, and ZEA degradation by recombinant E. coli was relatively rapid and effective, leaving no detectable ZEA after 72 h. In further experiments, cell-free extract of E.coli have been used in the same way, both to confirm these observations and the enzymatic nature of the degradation activity.