Reductive Dechlorination of Tetrachloroethene to trans-Dichloroethene and cis-Dichloroethene by PCB-Dechlorinating Bacterium DF-1

• Published in: Environmental science & technology Vol. 39; no. 8; pp. 2631 - 2635
• Main Authors: Miller, Gregory S, Milliken, Charles E, Sowers, Kevin R, May, Harold D
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.04.2005
• Subjects: Anaerobiosis; Applied sciences; Bacteria; Bacteria - metabolism; Biodegradation of pollutants; Biodegradation, Environmental; Biological and medical sciences; Biotechnology; Chlorine - chemistry; Coculture Techniques; Decontamination. Miscellaneous; Dichloroethylenes - metabolism; Earth sciences; Earth, ocean, space; Electrophoresis; Engineering and environment geology. Geothermics; Environment and pollution; Environmental Pollutants - metabolism; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Groundwaters; Industrial applications and implications. Economical aspects; Methylococcaceae; Natural water pollution; Oxidation-Reduction; Pollution; Pollution, environment geology; Polychlorinated Biphenyls - metabolism; RNA, Ribosomal, 16S - analysis; Soil and sediments pollution; Soil Microbiology; Stereoisomerism; Tetrachloroethylene - metabolism; Water treatment and pollution; Biodegradation; Microbial activity; Dehalogenation; Denaturing gradient gel electrophoresis; Soil pollution; Sediments; Ethylene(tetrachloro); Persistent organic pollutant; Polymerase chain reaction; Dechlorination; Decontamination; Anaerobe; Chlorine Organic compounds; Water pollution; Bioremediation; Organic compounds; Ground water; Ethylene(trichloro)
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es048849t

Polychlorinated biphenyls (PCBs) and chlorinated ethenes (CEs) are known to pollute sediment, soil, and groundwater. The anaerobic dechlorination of these compounds is an integral part of their biodegradation in polluted environ ments. We report for the first time the dechlorination of tetrachloroethene (PCE) and trichloroethene (TCE) by bacterium DF-1. This PCB and chlorobenzene dechlorinating bacterium dechlorinated PCE to TCE, which was then converted into trans-1,2-dichloroethene (trans-DCE) and cis-1,2-dichloroethene (cis-DCE). The ratio of trans-DCE to cis-DCE produced by the culture had a range of 1.2−1.7. Bacterium DF-1 has been enriched in co-culture with a desulfovibrio-like microorganism. PCR−denaturing gradient gel electrophoresis (PCR−DGGE) analysis of the 16S rRNA genes of the co-culture demonstrated that DF-1 was enriched during the dechlorination of PCE, PCB, and chlorobenzene. DF-1 was not detected in the absence of PCE dechlorination and the desulfovibrio-like organism, isolated in pure culture, did not dechlorinate PCE. This is the first identification of a microorganism capable of producing high amounts of trans-DCE from PCE and indicates that microorganisms such as DF-1 are a possible biological source of trans-DCE in the environment.