Microbial degradation of chlorinated dioxins

• Published in: Chemosphere (Oxford) Vol. 71; no. 6; pp. 1005 - 1018
• Main Authors: Field, Jim A., Sierra-Alvarez, Reyes
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.04.2008; Elsevier
• Subjects: Aerobiosis; Applied sciences; Bacteria - growth & development; Bacteria - metabolism; Benzofurans - chemistry; Benzofurans - metabolism; Biodegradation; Biodegradation of pollutants; Biodegradation, Environmental; Biological and medical sciences; Biotechnology; Biotransformation; Burkholderia; Dechlorination; Dehalococcoides; Dibenzofurans, Polychlorinated; Dioxins - chemistry; Dioxins - metabolism; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Global environmental pollution; Industrial applications and implications. Economical aspects; Molecular Structure; Pollution; Pollution, environment geology; Polychlorinated dibenzodioxins; Polychlorinated Dibenzodioxins - analogs & derivatives; Polychlorinated Dibenzodioxins - chemistry; Polychlorinated Dibenzodioxins - metabolism; Polychlorinated furans; Pseudomonas; Pseudomonas veronii; Sphingomonas; Biodegradation; Dechlorination; Polychlorinated dibenzodioxins; Polychlorinated furans; Biotransformation; Pseudomonadales; Microbial activity; Dioxin derivatives; Metabolic pathway; Review; Pseudomonas; Cometabolism; Fungi; Persistent organic pollutant; Pollution; Decontamination; Selfpurification; Bacteria; Pseudomonadaceae; Bioremediation; Fungi Imperfecti; Organic compounds; Environment; Poison; Kinetics
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2007.10.039

Polychlorinated dibenzo- p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were introduced into the biosphere on a large scale as by-products from the manufacture of chlorinated phenols and the incineration of wastes. Due to their high toxicity they have been the subject of great public and scientific scrutiny. The evidence in the literature suggests that PCDD/F compounds are subject to biodegradation in the environment as part of the natural chlorine cycle. Lower chlorinated dioxins can be degraded by aerobic bacteria from the genera of Sphingomonas, Pseudomonas and Burkholderia. Most studies have evaluated the cometabolism of monochlorinated dioxins with unsubstituted dioxin as the primary substrate. The degradation is usually initiated by unique angular dioxygenases that attack the ring adjacent to the ether oxygen. Chlorinated dioxins can also be attacked cometabolically under aerobic conditions by white-rot fungi that utilize extracellular lignin degrading peroxidases. Recently, bacteria that can grow on monochlorinated dibenzo- p-dioxins as a sole source of carbon and energy have also been characterized ( Pseudomonas veronii). Higher chlorinated dioxins are known to be reductively dechlorinated in anaerobic sediments. Similar to PCB and chlorinated benzenes, halorespiring bacteria from the genus Dehalococcoides are implicated in the dechlorination reactions. Anaerobic sediments have been shown to convert tetrachloro- to octachlorodibenzo- p-dioxins to lower chlorinated dioxins including monochlorinated congeners. Taken as a whole, these findings indicate that biodegradation is likely to contribute to the natural attenuation processes affecting PCDD/F compounds.