An aerobic enrichment culture derived from a groundwater contaminated with organic and chloroorganic compounds was adapted to the transformation of 2,2 ' -dichlorodiisopropyl ether (DDE) in a continuous fixed-bed bioreactor. Continuous DDE removal efficiencies over 90% were achieved with a model water containing 3.3 mM methanol as co-substrate at DDE loading rates of up to 150 pmol l(-1) day(-1) with a hydraulic retention time of 24 h. In batch cultures, a stoichiometric release of 2 mu mol chloride per pmol DDE transformed was observed. From the mixed culture, a strain was isolated that is able to grow on DDE as the sole energy and carbon source, tolerating DDE concentrations of up to 1 mM. Based on 16S rRNA sequencing, the strain is affiliated with the genus Rhodococcus.