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Updated: Jul 9, 2026
15:19
Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
Published on: October 15, 2015
Microbial degradation of chlorinated dioxins
Jim A Field1, Reyes Sierra-Alvarez
1Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ 85721, USA. Jimfield@email.arizona.edu
Chemosphere
|December 18, 2007
Summary
Biodegradation breaks down toxic polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF). Aerobic bacteria and fungi degrade lower chlorinated forms, while anaerobic bacteria reduce higher chlorinated dioxins, aiding natural attenuation.
Area of Science:
- Environmental Microbiology
- Bioremediation
- Environmental Chemistry
Background:
- Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) are toxic by-products of industrial processes and waste incineration.
- Their persistence and toxicity have led to significant public and scientific concern regarding environmental contamination.
Purpose of the Study:
- To review and synthesize the existing literature on the biodegradation of PCDD/F compounds.
- To highlight the microbial mechanisms involved in the degradation of various chlorinated dioxin congeners.
Main Methods:
- Literature review of studies investigating microbial degradation pathways of PCDD/Fs.
- Analysis of findings related to both aerobic and anaerobic biodegradation processes.
- Identification of key microbial genera and enzymes involved in dechlorination.
Main Results:
- Aerobic biodegradation of lower chlorinated PCDD/Fs is facilitated by bacteria (Sphingomonas, Pseudomonas, Burkholderia) and fungi, often involving angular dioxygenases.
- Specific bacteria like Pseudomonas veronii can utilize monochlorinated dioxins as a sole carbon and energy source.
- Anaerobic biodegradation of higher chlorinated PCDD/Fs occurs via reductive dechlorination, with Dehalococcoides species implicated in converting highly chlorinated forms to less chlorinated congeners.
Conclusions:
- Biodegradation plays a significant role in the natural attenuation of PCDD/F compounds in the environment.
- Understanding these microbial processes is crucial for developing effective bioremediation strategies for dioxin-contaminated sites.
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