Dehalogenation: A Novel Pathway for the Anaerobic Biodegradation of Haloaromatic Compounds

Abstract

Microorganisms of lake sediment and sewage sludge anaerobically metabolized halobenzoates by a novel pathway. The primary degradative event was loss of the aryl halide without the alteration of the aromatic ring. Dehalogenation required strict anaerobic conditions and depended on the halogen and position, but not the number of halogen substituents. A stable methanogenic bacterial consortium was enriched from sludge and found capable of dehalogenating and often mineralizing a variety of halobenzoates to CH₄ and CO₂. The results suggest that reductive dehalogenation of aromatics could be important in removal of some chlorinated xenobiotics from the environment.