Reductive <i>ortho</i> and <i>meta</i> Dechlorination of a Polychlorinated Biphenyl Congener by Anaerobic Microorganisms

Abstract

We used gas chromatography-mass spectrometry to study the metabolic fate of 2,3,5,6-tetrachlorobiphenyl (2356-CB) (350 muM) incubated with unacclimated methanogenic pond sediment. The 2356-CB was dechlorinated to 25-CB (21%), 26-CB (63%), and 236-CB (16%) in 37 weeks. This is the first experimental demonstration of ortho dechlorination of a polychlorinated biphenyl by anaerobic microorganisms.