A bacterium with an exceptional ability to hydrolyse fenamiphos and its toxic oxidation products fenamiphos sulfoxide and fenamiphos sulfone, all possessing P-O-C bond was isolated from soil. Based on 16S rRNA gene determination, this bacterium was putatively identified as Microbacterium esteraromaticum. The phenols fenamiphos phenol, sulfoxide phenol and sulfone phenol) formed during bacterial hydrolysis resisted further degradation in mineral salts medium and sterile groundwater, but were transitory in non-sterile groundwater due to the catabolism of native microorganisms. Also, the cell-free preparation of this bacterium was highly effective in hydrolysing fenamiphos and its oxides. These results demonstrate the potential of this bacterium to detoxify pesticide waste in the environment including the groundwater. (C) 2008 Elsevier Ltd. All rights reserved.