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Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
Published on: October 15, 2015
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Acetylene Fuels TCE Reductive Dechlorination by Defined Dehalococcoides/Pelobacter Consortia.
Xinwei Mao1, Ronald S Oremland2, Tong Liu1
1Department of Civil and Environmental Engineering, College of Engineering, University of California , Berkeley, California 94720-1710, United States.
Environmental Science & Technology
|January 12, 2017
Summary
Acetylene (C2H2) can inhibit bacterial dechlorination of trichloroethene (TCE) at high concentrations. However, low acetylene levels and its co-cultivation with Pelobacter SFB93 support TCE bioremediation by Dehalococcoides mccartyi.
Area of Science:
- Environmental microbiology
- Bioremediation science
Background:
- Acetylene (C2H2) is a byproduct of trichloroethene (TCE) degradation in contaminated groundwater.
- Acetylene is known to inhibit bacterial dechlorination, a key process in TCE bioremediation.
Purpose of the Study:
- To investigate the effect of different acetylene concentrations on Dehalococcoides mccartyi.
- To evaluate the potential of co-culturing Dehalococcoides mccartyi with acetylene-degrading bacteria for enhanced TCE bioremediation.
Main Methods:
- Microcosm experiments with Dehalococcoides mccartyi isolates and enrichment cultures.
- Co-cultivation experiments with Pelobacter SFB93 and D. mccartyi strains.
- Transcriptomic analysis of D. mccartyi strain 195 under acetylene inhibition.
Main Results:
- High acetylene concentrations (1.3 mM) reversibly inhibited TCE reductive dechlorination by D. mccartyi.
- Low acetylene concentrations (0.4 mM) did not inhibit D. mccartyi growth or metabolism.
- Co-culturing with Pelobacter SFB93 sustained D. mccartyi activity and overcame acetylene inhibition.
- Transcriptomic data revealed downregulation of ATP synthase and hydrogenase genes during acetylene inhibition.
Conclusions:
- Acetylene's inhibitory effect on TCE bioremediation is concentration-dependent.
- Pelobacter SFB93 can mitigate acetylene's negative impact, enabling effective TCE bioremediation.
- Understanding these interactions is crucial for optimizing bioremediation strategies at contaminated sites.
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