Strain SF3, a gram-negative, anaerobic, motile, short curved rod that grows by coupling the reductive dechlorination of 2-chlorophenol (2-CP) to the oxidation of acetate, was isolated from San Francisco Bay sediment. Strain SF3 grew at concentrations of NaCl ranging from 0.16 to 2.5%, but concentrations of KCl above 0. 32% inhibited growth. The isolate used acetate, fumarate, lactate, propionat...

Kinetic studies with two different anaerobic mixed cultures (the PM and the EV cultures) were conducted to evaluate inhibition between chlorinated ethylenes. The more chlorinated ethylenes inhibited the reductive dechlorination of the less chlorinated ethylenes, while the less chlorinated ethylenes weakly inhibited the dechlorination of the more chlorinated ethylenes. Tetrachloroethylene (PCE) ...

The infiltration of dense non-aqueous-phase liquids (DNAPLs) into the saturated subsurface typically produces a highly contaminated zone that serves as a long-term source of dissolved-phase groundwater contamination. Applications of aggressive physical-chemical technologies to such source zones may remove > 90% of the contaminant mass under favorable conditions. The remaining contaminant mass, ...

Title of Document: THE ROLE OF DEHALORESPIRING BACTERIA IN THE REDUCTIVE DECHLORINATION OF POLYCHLORINATED BIPHENYLS IN BALTIMORE HARBOR SEDIMENT MICROCOSMS Sonja Kristine Fagervold, Doctor of Philosophy, 2007 Directed By: Professor Kevin R. Sowers, Marine Estuarine Environmental Sciences Baltimore Harbor sediment microcosms were incubated with the 12 most predominant congeners in Aroclor 1260 ...

A study to evaluate the dechlorination end points and the most promising electron donors to stimulate the reductive dechlorination process at the chloroethene-contaminated Bachman Road site in Oscoda, MI, was conducted. Aquifer materials were collected from inside the plume and used to establish microcosms under a variety of electron donor conditions using chlorinated ethenes as electron accept...

Polyhalogenated compounds are often environmentally persistent and toxic to mammals. Microorganisms that metabolize these compounds can detoxify contaminated environments. Different biochemical mechanisms are used to metabolize polyhalogenated compounds, but few naturally occurring bacteria have this capability. A recombinant bacterium was constructed to metabolize polyhalogenated compounds to ...

Recent field studies have indicated synergistic effects of coupling microbial reductive dechlorination with physicochemical remediation (e.g., surfactant flushing) of dense nonaqueous phase liquid (DNAPL) source zones. This study explored chlorinated ethene (e.g., tetrachloroethene [PCE]) dechlorination in the presence of 50-5000 mg/L Tween 80, a nonionic surfactant employed in source zone reme...

2-Bromoethanesulfonate (BES) inhibited the reductive dechlorination of chloroethenes in several sediment-free enrichment cultures in the absence of methanogenic archaea. Archaeon-specific PCR primers confirmed the absence of methanogens in the enrichment cultures. BES should not be used to attribute dechlorination activities to methanogens.

The chlorinated solvents tetrachloroethene (PCE) and trichloroethene (TCE) have been used extensively in industry and are now amongst the most common and hazardous groundwater contaminants (National Research Council, 2004). These solvents are typically present as dense, non-aqueous phase liquids (DNAPLs) and represent long-term source zones that produce persistent contamination plumes in aquife...