Scientists have traditionally relied on consortia of bacteria to degrade nasty mixtures of chlorinated hydrocarbons that often are recalcitrant environmental contaminants. Now, a team of German researchers has isolated a bacterium that is capable of degrading chlorobenzenes in isolation (Nature 408, 580–583, 2000). The researchers obtained the strain, designated CBDB1, from a bioreactor containing a mixture of bacteria that were capable of dechlorinating chlorobenzenes. According to Lorenz Adrian, lead author on the paper, the bacterium cannot survive in the absence of the chlorobenzene, and is strictly anaerobic, requiring a hydrogen source and chlorobenzene as an electron donor. It is thought that CBDB1 forms a new bacterial cluster together with Dehalococcoides ethenogenes. The German team believes that isolation of the bacterium will facilitate research to define more precisely the conditions that favor rapid breakdown of the chlorinated solvent. Ultimately, this should enable more effective bioremediation of waste sites contaminated with chlorinated hydrocarbons.