TY - JOUR
T1 - Geochemistry and microbial diversity of a trichloroethene-contaminated Superfund site undergoing intrinsic in situ reductive dechlorination
AU - Lowe, Mary
AU - Madsen, Eugene L.
AU - Schindler, Karen
AU - Smith, Courtney
AU - Emrich, Scott
AU - Robb, Frank
AU - Halden, Rolf U.
N1 - Funding Information:
This work was supported by funds from DOE EM-40 under contract W-7405-Eng-48, DOE’s Accelerated Site Technology Deployment Program, Loyola matching funds for students pertaining to DOE NABIR grant DE-FG02-99ER62868, DOE grant DE-FG07-96ER62320, and NSF grant CTS-9253633. We would like to thank L. Semprini, S. Vancheeswaran, S. Yu, and M-Y. Chu for quantifying tetraalkoxysilanes and their transformation products. We also would like to thank S. Gregory and V. Madrid for assisting in groundwater sampling and plume contouring, and D. Brown for assisting in DNA extraction and processing. We acknowledge the assistance of L. Petersen, K. Sorensen and R. Starr in converting the Building 834 Study Area at LLNL Site 300 into an ASTD deployment site for monitored natural attenuation and in situ bioremediation. Finally, we would like to thank the Institute of Genomic Research (TIGR) for sequence data.
PY - 2002
Y1 - 2002
N2 - This study explored the geochemistry and microbial diversity of a Superfund site containing trichloroethene (TCE) and an unusual co-pollutant, tetrakis(2-ethylbutoxy)silane. Geochemical analysis of contaminated groundwater indicated subsurface anaerobiosis, reductive dechlorination of TCE to predominantly cis-1,2-dichloroethene, and (transient) accumulation of 2-ethylbutanol and 2-ethylbutyrate as a result of tetrakis(2-ethylbutoxy)silane breakdown. Comparative analysis of 106 16S rDNA and 61 16S-23S rDNA intergenic spacer region sequences - obtained from pristine and contaminated groundwater via DNA extraction, PCR amplification, cloning and sequencing - revealed that the contaminated groundwater featured (i) a distinct microbial community, (ii) reduced species diversity, (iii) various anaerobes, and (iv) bacteria closely related to the TCE-dechlorinating, dichloroethene-accumulating genus Dehalobacter, whereas (v) the TCE-dechlorinating, ethene-producing species Dehalococcoides ethenogenes was not detectable. Thus, geochemical and molecular biological results were in excellent agreement in this first ecological field study linking in situ reductive dechlorination of TCE to metabolism of tetraalkoxysilanes.
AB - This study explored the geochemistry and microbial diversity of a Superfund site containing trichloroethene (TCE) and an unusual co-pollutant, tetrakis(2-ethylbutoxy)silane. Geochemical analysis of contaminated groundwater indicated subsurface anaerobiosis, reductive dechlorination of TCE to predominantly cis-1,2-dichloroethene, and (transient) accumulation of 2-ethylbutanol and 2-ethylbutyrate as a result of tetrakis(2-ethylbutoxy)silane breakdown. Comparative analysis of 106 16S rDNA and 61 16S-23S rDNA intergenic spacer region sequences - obtained from pristine and contaminated groundwater via DNA extraction, PCR amplification, cloning and sequencing - revealed that the contaminated groundwater featured (i) a distinct microbial community, (ii) reduced species diversity, (iii) various anaerobes, and (iv) bacteria closely related to the TCE-dechlorinating, dichloroethene-accumulating genus Dehalobacter, whereas (v) the TCE-dechlorinating, ethene-producing species Dehalococcoides ethenogenes was not detectable. Thus, geochemical and molecular biological results were in excellent agreement in this first ecological field study linking in situ reductive dechlorination of TCE to metabolism of tetraalkoxysilanes.
KW - 16S rDNA
KW - 16S-23S intergenic spacer region
KW - Bioremediation
KW - Reductive dechlorination
KW - Tetraalkoxysilane
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U2 - 10.1016/S0168-6496(02)00229-5
DO - 10.1016/S0168-6496(02)00229-5
M3 - Article
C2 - 19709219
AN - SCOPUS:0036284215
SN - 0168-6496
VL - 40
SP - 123
EP - 134
JO - FEMS microbiology ecology
JF - FEMS microbiology ecology
IS - 2
ER -