Isolation of soil bacteria able to hydrolyze both organophosphate and carbamate pesticides

Abstract

Two bacteria identified as Pseudomonas putida and Acinetobacter rhizosphaerae able to rapidly degrade the organophosphate (OP) fenamiphos (FEN) were isolated. Denaturating gradient gel electrophoresis analysis revealed that the two isolates were dominant members of the enrichment culture. Clone libraries further showed that bacteria belonging to alpha-, beta-, gamma-proteobacteria and Bacteroidetes were also present in the final enrichment but were not isolated. Both strains hydrolyzed FEN to fenamiphos phenol which was further transformed, only by P. putida. The two strains were using FEN as C and N source. Cross-feeding studies with other pesticides showed that P. putida degraded OPs with a P-O-C linkage and unexpectedly degraded the carbamates oxamyl and carbofuran being the first wild-type bacterial strain able to degrade both OPs and carbamates. The same isolate exhibited high bioremediation potential against spillage-level concentrations of aged residues of FEN and its oxidized derivatives. (C) 2010 Elsevier Ltd. All rights reserved.