United States
               Environmental Protection
               Agency
 Environmental
 Research Laboratory
 Athens, GA 30605-2720
               Research and Development
EPA      Project  Summary
 EPA/600/SR-93/131   September 1993
               Anaerobic Dehalogenation  and
               Its Environmental  Implications
               John E. Rogers and Daniel A. Abramowicz
                  In an international conference, rni-
               crobiologists from five countries pre-
               sented  results  of research into  the
               anaerobic  dehalogenation  of  com-
               pounds of  environmental interest be-
               ing performed at selected universities,
               government agencies, and private com-
               panies.  The conference, held from Au-
               gust 30 to September 4, 1992, in Ath-
               ens, GA, was sponsored by the Ameri-
               can  Society for Microbiology.  This
               document provides abstracts of the 33
               papers presented at the conference in
               sessions addressing the environmen-
               tal fate  of chlorinated organic chemi-
               cals; the anaerobic dechloiination  of
               chlorinated  phenols; the dechlorination
               of polychlorinated biphenyls; the
               dehalogenation of aliphatic  com-
               pounds; the abiotic dechlorination  of
               porphryns,  corrins, and non-tetrapyr-
               roles; the kinetics of dehalogenatioris;
               the microbial physiology of dechlori-
               nating systems; and the hydrolytic
               dehalogenation  of compounds.  Re-
               search results were provided for a vari-
               ety of compounds, including polychlo-
               rinated  biphenyls,  pentachloro-
               dibenzodioxin, polychlorinated phenols,
               2,4-dichlorophenol,  aroclors,  1,2-
               dichloroethane, tetrachloroethene, me-
               thyl chloride, perchloroethylene, 2,4,5-
               trichlorophenoxyacetic  acid  and
               pentachlorodibenzofuran.
                This Project Summary was developed
               by  EPA's  Environmental Research
               Laboratory, Athens, GA, to announce
               key findings of the  research project
               that is fully documented in a separate
               report of the same title  (see Project
               Report ordering information at back).
Conference Overview
  Chlorinated chemicals continue to make
an . impact  on  our daily lives. Many of
these impacts are positive.  For example,
chlorinated chemicals currently are used
as solvents, oils, and pesticides. Undesir-
able consequences, however, also can be
associated with these materials.  Many of
these chemicals as well as their degrada-
tion products are considered  hazardous
and can pose  problems to humans and
other life forms when the compounds en-
ter the environment. The extent of the
impact is dependent on the exposure route
and the length of exposure.
   Considerable scientific effort continues
to be directed toward understanding the
chemical and biological processes that af-
fect the fate of chemicals in the environ-
ment. The close relationship between the
susceptibility of chlorinated  chemicals to
microbial degradation and their persistence
in the environment has led to numerous
investigations. These research efforts ini-
tially focused on aerobic degradation with
anaerobic degradation receiving attention
mostly in the last decade. Revealed sus-
ceptibility to microbial degradation also led
to investigations leading to the use of bio-
remediation in the cleanup  of sites con-
taminated with chlorinated chemicals.
   In an effort to integrate the findings of
some of the numerous investigators in
laboratories across the United States and
other countries who are addressing the
many aspects of the environmental fate of
chlorinated chemicals and the potental use
of bioremediation  in contaminated site
cleanup, the U.S. Environmental Protec-
tion Agency and other organizations sup-
ported a conference in the summer of
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1992 that was sponsored by the Ameri-
can Society for Microbiology.  The sup-
porting organizations—EPA, the Depart-
ment of Energy, General Electric, the Na-
tional  Science Foundation, and  the  Na-
tional  Institute of Environmental Health
Sciences—join w'rtn tne American Society
for Microbiology in the belief that a com-
mon sharing of results will lead to better
remedial  options, provide a database for
developing  regulatory options, and focus
on critical basic research needs.

Compiled Abstracts
  1. Fate of Chlorinated Aromatic Com-
pounds in a Sediment Area of the Rhine
River (J.E.M.  Buerskens, J.  deWolf, M.
Swart, and C.G.C.  Dekker), 2. Reductive
Dechlorination of PCBs and PCDDs by
Consort/a Isolated from Dutch Sediments
(J.R.  Parsons, L.C.M. Commandeur, M.
Toussaint, and J.E.M. Buerskens), 3.
Anaerobic  Microbial PCB Dechlorination
in the Environment (J.F.  Brown), 4.
Anaerobic  Dehalogenation of Pesticides
In Subsurface Environments (J.M. Suflita),
5. Anaerobic Degradation of Chlorinated
Aromatic Hydrocarbons Using Acclimated
 Cultures (J.E. Rogers, W.J. Jones,  D.D.
Hale, and D. Wubah).
    6. Sequential Degradation  of 2,4-
 Dlchlorophenol and Analogous Com-
pounds (J. Wiegel), 7. Different Reducing
 Conditions and Chlorophenol Metabolism
 (L.Y.  Young, M.M.  Haggblom, J. Kazumi,
 and M.D.  Rivera,  8. Cross-reactivity of
 PCP-degrading Organisms (J. Struijs), 9.
 Simulation of Reductive Dechlorination of
 Arochlor 1260 Contaminant in Anaerobic
 Slurries  of Woods Pond Sediment  (D.L.
 Bedard,  H.M. Van Dort, S.C. Bunnell, J.M.
 Principe, K.A. DeWeerd,  R.J. May, and
L.A. Smullen), 10. Reductive Dechlorina-
tion  in  Different  Sediments  (M.M.
Haggblom, A.C. Alder, S.R. Oppenheimer,
and L.Y. Young.
  11.   Factors  Affecting  in situ  PCB
Dechlorination and the Expected Toxicity
Reduction (J.F.  Quensen),  12.  Hudson
RiverLaboratory and  Environmental
Changes (D.A.  Abramowicz), 13.  PCB
Dechlorination: Large  Scale Efforts and
Sequential Anaerobic-Aerobic Treatment
(P.A. Anid, L Nies, B.P. Ravest-Webster,
and T.M. Vogel),  14. Anaerobic Biotrans-
formation of PCBs and Determining Fac-
tors (G-Y. Rhee and R.C.,Sokol), 15. Ef-
fect of Temperature on the Dechlorination
of PCBs in Woods Pond  Sediment (J.
Wiegel).
   16. Reductive Dechlorination of 1,2-
Dichloroethane  and  Tetrachloroethene
Catalyzed by Anaerobic  Bacteria (C.
Hollinger),  17.   Complete Anaerobic
Dechlorination of Tetrachloroethane in a
Bioreactor (W.P.  de Bruin, G. Schraa, and
A.R.J. Zehnder), 18.  A CH3CL Utilizing
Homoacetogen (G.  Diekert), 19.  Factors
Effecting PCE Dechlorination in the Sub-
surface (G.W. Sewell, S.A. Gibson, and
H.H. Russell), 20. Simulation of Anaerobic
2,4,5-T Degradation (S.A. Gibson and J.M.
Suflita).
   21.  Dehalogenation of  Highly Chlori-
nated PCDDs and  PCDFs: Retention  of
the 2,3,7,8-Sequence (P. Adriaens and  D.
Grbic-Galic), 22.  Reductive  Dehalo-
genation by Bacteria: A  Competition with
 Oxygen and Oxidation (C.E. Castro), 23.
 The  Use of Porphyrins  and Corrins  in
 Detoxification (T.S. Marks and A. Maule),
24.  Enzymatic and Coenzymatic Reduc-
 tive  Dehalogenation: Mechanisms and
Applications (L.  Wackett), 25.  Electro-
catalytic Dehalogenations (J.F. Rusling).
   26. Natural Chemical Attenuation of
Halogenated Hydrocarbon Compounds Via
Dehalogenation Reactions (M. Reinhard),
27.  Synthetic Nickel Complexes as
Dehalogenation Catalysts  (M. Stiles), 28.
Factors Affecting Dichlorophenol Reduc-
tion  Kinetics (D.D.  Hale), 29. Reductive
Transformation of Halogenated Aromatic
Hydrocarbons  in Anaerobic  Water-Sedi-
ment Systems:  Kinetics,  Mechanisms,
Products  and   QSARs   (W.G.J.M.
Peijnenburg,  N.L.  Bilthoven, and  N.L.
Wolfe), 30. Dechlorination and ATP For-
mation in Desulfomonile tiedje (J. Dolfing).
  31. Development and Characterization
of an Anaerobic Bacterial Co-culture which
Dechlorinates 3-Chlorobenzoate (B.
Sharak Genthner), 32. From Molecular Bi-
ology to Treatment: Activities  and Adapta-
tions of Dehalogenases  (D.B. Janssen,
M. Pentenga, R. Bos, and F. Pries), and
33.  Dechlorination Enzymology: Halido-
hydrolases from  Pseudomonas spec.
Strain CBS3 (S. Fetzer, B. Schneider, F.
Loftier, R. Muller, and F. Lingens).
  The organizing committee  for the con-
ference was composed of Dr.  John
Rogers,  U.S. Environmental Protection
Agency,   Athens  GA;  Dr.   Daniel
Abramowicz,  General  Electric Research
and Development Center,  Schenectady
NY; Dr. Hugh Russell, U.S. Environmental
Protection  Agency, Ada OK; Dr. Joseph
Suflita, University  of Oklahoma, Norman
OK; Dr. Lily  Young,  Rutgers University,
 New Brunswick NJ;  and  Dr. Alexander
Zehnder,    Agricultural   University,
Wageningen, The Netherlands.
                                                                     •A-U.S. GOVERNMENT PRINTING OFFICE: 1993 - 750-071/80077

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John E. Rogers (also the EPA Project Officer, see below) is with the Environmental
  Research Laboratory, Athens, GA 30605-2720;  Daniel A. Abramowicz is with
  the General Electric  Corporate Research and Development Center,
  Schenectady, NY 12301.
The complete report, entitled "Anaerobic Dehalogenation and Its Environmental
  Implications: Abstracts of 1992 American Society for Microbiology Conference,"
  (OrderNo. PB93-217799AS;  Cost: $19.50; subject to change) will be available
  only from:
        National Technical Information Service
        5285 Port Royal Road
        Springfield, VA 22161
        Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
        Environmental Research Laboratory
        U.S. Environmental Protection Agency
        Athens, GA 30605-2720
  United States
  Environmental Protection Agency
  Center for Environmental Research Information
  Cincinnati, OH 45268

  Official Business
  Penalty for Private Use
  $300

  EPA/600/SR-93/131
     BULK RATE
POSTAGE & FEES PAID
         EPA
   PERMIT No. G-35

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