title: In situ TCE degradation mediated by complex dehalorespiring communities during biostimulation processes.
abstract: The bioremediation of chloroethene contaminants in groundwater polluted systems is still a serious environmental challenge. Many previous studies have shown that cooperation of several dechlorinators is crucial for complete dechlorination of trichloroethene to ethene. In the present study, we used an explorative functional DNA microarray (DechloArray) to examine the composition of specific functional genes in groundwater samples in which chloroethene bioremediation was enhanced by delivery of hydrogen-releasing compounds. Our results demonstrate for the first time that complete biodegradation occurs through spatial and temporal variations of a wide diversity of dehalorespiring populations involving both Sulfurospirillum, Dehalobacter, Desulfitobacterium, Geobacter and Dehalococcoides genera. Sulfurospirillum appears to be the most active in the highly contaminated source zone, while Geobacter was only detected in the slightly contaminated downstream zone. The concomitant detection of both bvcA and vcrA genes suggests that at least two different Dehalococcoides species are probably responsible for the dechlorination of dichloroethenes and vinyl chloride to ethene. These species were not detected on sites where cis-dichloroethene accumulation was observed. These results support the notion that monitoring dechlorinators by the presence of specific functional biomarkers using a powerful tool such as DechloArray will be useful for surveying the efficiency of bioremediation strategies.
authors.affiliation: Clermont Université, Université Blaise Pascal, Laboratoire Microorganismes: Génome et Environnement, BP 10448, F63000, Clermont-Ferrand, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Dugat-Bony
authors.forename: Corinne
authors.initials: C
authors.lastname: Biderre-Petit
authors.forename: Faouzi
authors.initials: F
authors.lastname: Jaziri
authors.forename: Maude M
authors.initials: MM
authors.lastname: David
authors.forename: Jérémie
authors.initials: J
authors.lastname: Denonfoux
authors.forename: Delina Y
authors.initials: DY
authors.lastname: Lyon
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Richard
authors.forename: Cyrille
authors.initials: C
authors.lastname: Curvers
authors.forename: Delphine
authors.initials: D
authors.lastname: Boucher
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Vogel
authors.forename: Eric
authors.initials: E
authors.lastname: Peyretaillade
authors.forename: Pierre
authors.initials: P
authors.lastname: Peyret
mesh_terms: D058448:Biota; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004980:Ethane / Q000378:metabolism; D060587:Groundwater / Q000382:microbiology*; D054892:Metagenome; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D017422:Sequence Analysis, DNA; D014241:Trichloroethylene / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D014874:Water Pollutants, Chemical; D014241:Trichloroethylene; D004980:Ethane