Evidence for the aerobic degradation of tetrachloroethylene by a bacterial isolate

Deckard, Lindsey A.; Willis, Jacob; Rivers, Douglas B.

doi:10.1007/bf01020855

Cited by 11 publications

(4 citation statements)

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“…Microbial degradation of CHBr 3 appears to be insignificant [ Goodwin et al , 1997], while bacterial degradation of CH 2 Br 2 is faster than its hydrolysis [ Goodwin et al , 1998]. Aerobic bacterial degradation of chloroform (CHCl 3 ), 1,2‐dibromoethane, 1,2‐dichloroethane, and tetrachloroethene (PCE) has also been observed [ Castro , 1993; Deckard et al , 1994]. However, biological degradation rate constants for the short‐lived species have not been included in these model runs, because there is not enough information to attempt a global extrapolation of these loss processes.…”

Section: Resultsmentioning

confidence: 99%

Effect of oceanic uptake on atmospheric lifetimes of selected trace gases

Yvon‐Lewis

2002

J. Geophys. Res.

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[1] We have calculated from a 2°Â 2°grid of oceanic properties the contribution of oceanic loss to the overall lifetimes of a number of anthropogenic and naturally produced trace gases involved in global warming and stratospheric ozone depletion. The model, originally developed for atmospheric methyl bromide, can be used for any well-mixed trace gas where the seawater degradation rate constants and solubilities are known. Of the gases tested, it is clear that known oceanic chemical degradation processes alone are not significant sinks for most HFCs and HCFCs. Chemical degradation in the oceans is a substantial sink for COS (28%) and COCl 2 (8%) and a minor sink for CH 3 Cl (<2%) and CH 3 I (2.5%), and it should be considered when determining atmospheric lifetimes and sink strengths for these gases. Biological degradation processes are likely to increase the oceanic uptake rates of many gases.

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Section: Resultsmentioning

confidence: 99%

Effect of oceanic uptake on atmospheric lifetimes of selected trace gases

Yvon‐Lewis

2002

J. Geophys. Res.

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“…PCE is of particular concern because it is resistant to degradation by aerobic bacteria. In fact, only one aerobic bacterium has exhibited evidence of metabolizing PCE (Deckard et al, 1994) and those results have not been corroborated.…”

Section: Introductionmentioning

confidence: 92%

Degradation of perchloroethylene and dichlorophenol by pulsed-electric discharge and bioremediation

Yee

Chauhan

Yankelevich

et al. 1998

Biotechnol. Bioeng.

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Pulsed electric discharge (PED) and bioremediation were combined to create a novel two-stage system which dechlorinates the halogenated pollutants, 2,4dichlorophenol and perchloroethylene, with repetitive (0.1-1 kHz), short pulse (∼100 ns), low voltage (40-80 kV) discharges and then mineralizes the less chlorinated products with aerobic bacteria. A 6.1 mM aqueous dichlorophenol sample was cycled through the PED reactor (60 kV of applied pulsed voltage and 300 Hz) 6 times, resulting in the release of 55% of the initial dichlorophenol chloride ions (1 mM Cl − removed each cycle). The respective average specific efficiency is 0.4-0.6 keV/(Cl − molecule). Pseudomonas mendocina KR1, which grows in minimal medium supplemented with phenol but not with dichlorophenol, increased in cell density in all cultures supplemented with the PED-treated DCP samples and yielded a maximum of twofold additional Cl − released compared to the PED-related alone. The number of PED-treatment cycles, voltage, and frequency were also varied, showing that both cell densities and overall dichlorophenol dechlorination were highly dependent upon the number of PED-treatment cycles, rather than the tested voltages and frequencies. Using this two-stage treatment system, PED released 31% of the initial chloride ions from dichlorophenol (after three cycles at 40-45 kV and 1.2 kHz) while P. mendocina KR1 in the second stage increased dechlorination to 90%. These results were corroborated by the 35% additional chloride release found with activated sludge cultures. Perchloroethylene (0.6 mM) was similarly treated in a first-stage PED reactor (80% chloride removal after four cycles) followed by biodegradation of the dechlorinated products with a recombinant toluene o-monooxygenase-expressing Pseudomonas fluorescens strain. Gas chromatographic analysis showed that the PED reactor created less-chlorinated byproducts (i.e., trichloroethylene) that were removed (74%) upon exposure to the recombinant bacterium.

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“…It is important to note that EDB undergoes some bacterial degradation in the ocean waters. However, this process is minimal when compared to the rate of atmospheric degradation. , …”

Section: Introductionmentioning

confidence: 99%

“…However, this process is minimal when compared to the rate of atmospheric degradation. 32,33 With a vapor pressure of 11 mmHg and Henry's law constant at 293 K of 3.16 × 10 -4 atm m 3 mol -1 , EDB volatilizes rapidly from water. 34,35 Therefore, solublized EDB is rapidly released into the gas phase and enters the atmosphere.…”

Section: Introductionmentioning

confidence: 99%

Atmospheric Oxidation Mechanism of 1,2-Dibromoethane

Christiansen

Francisco

2008

J. Phys. Chem. A

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The complete atmospheric oxidation mechanism of 1,2-dibromoethane is proposed. There are 32 species and 22 transition state species involved in the proposed mechanism. Geometry optimizations and frequency computations are performed using the second-order Møller-Plesset perturbation theory and the 6-31G(d) basis set for all species and transition states. Single-point energy computations are performed using fourth-order Møller-Plesset perturbation theory and coupled cluster theory. Potential energy surfaces, including activation energies and enthalpies, are determined from the computations. Final products of this degradation include OH, CO(2), CO, CH(2)(O), CH(O)CH(O) (glyoxal), bromine radicals, CH(O)Br, HOBr, and a reservoir for a new atmospheric compound, BrC(O)C(O)Br.

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Evidence for the aerobic degradation of tetrachloroethylene by a bacterial isolate

Cited by 11 publications

References 11 publications

Effect of oceanic uptake on atmospheric lifetimes of selected trace gases

Effect of oceanic uptake on atmospheric lifetimes of selected trace gases

Degradation of perchloroethylene and dichlorophenol by pulsed-electric discharge and bioremediation

Atmospheric Oxidation Mechanism of 1,2-Dibromoethane

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