title: Characterization of microbial communities in the aqueous phase of a constructed model wetland treating 1,2-dichloroethene-contaminated groundwater.
abstract: The dynamics and composition of microbial communities in the aqueous phase of a model wetland supplied with cis- and trans-1,2-dichloroethenes (DCE)-contaminated groundwater was characterized. PCR-denaturing gradient gel electrophoresis analysis of water samples obtained from different parts of the wetland revealed that changes of the bacterial community structure coincided with a succession of the hydrochemical conditions in the wetland, from oxic towards anoxic conditions. During this transition phase, the appearance of vinyl chloride and ethene correlated with the presence of putative dechlorinating bacteria (Dehalococcoides spp., Geobacter spp. and Dehalobacter spp.). Additionally, a shift of the DCE isotopic composition indicated the progressive prevalence of reductive dechlorination in the wetland. Although the DCE degradation processes varied over time, biodegradation activity was maintained in the wetland system. 16S rRNA gene libraries revealed that Proteobacteria accounted for >50% of 16S rRNA genes clone libraries, whereas approximately 17% of the sequences from the wetland were related to sulphate reducers. Based on a multiple-method approach, this study illustrates the linkage between microbial community dynamics and composition, changes of hydrochemical conditions and processes of DCE degradation in a wetland system.
authors.affiliation: Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany. gwenael.imfeld@engees.u-strasbg.fr
authors.forename: Gwenaël
authors.initials: G
authors.lastname: Imfeld
authors.forename: Cristian Estop
authors.initials: CE
authors.lastname: Aragonés
authors.forename: Ingo
authors.initials: I
authors.lastname: Fetzer
authors.forename: Eva
authors.initials: E
authors.lastname: Mészáros
authors.forename: Simone
authors.initials: S
authors.lastname: Zeiger
authors.forename: Ivonne
authors.initials: I
authors.lastname: Nijenhuis
authors.forename: Marcell
authors.initials: M
authors.lastname: Nikolausz
authors.forename: Sylvain
authors.initials: S
authors.lastname: Delerce
authors.forename: Hans H
authors.initials: HH
authors.lastname: Richnow
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D001673:Biodegradation, Environmental; D004269:DNA, Bacterial / Q000032:analysis; D004000:Dichloroethylenes / Q000032:analysis / Q000378:metabolism*; D005030:Ethylenes / Q000378:metabolism; D020459:Genes, rRNA; D054879:Halogenation; D058085:Iron Compounds / Q000032:analysis / Q000378:metabolism; D010084:Oxidation-Reduction; D010802:Phylogeny; D013440:Sulfides / Q000032:analysis / Q000378:metabolism; D014752:Vinyl Chloride / Q000378:metabolism; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D053833:Wetlands
chemical_list: D004269:DNA, Bacterial; D004000:Dichloroethylenes; D005030:Ethylenes; D058085:Iron Compounds; D013440:Sulfides; D014874:Water Pollutants, Chemical; C036216:ethylene; D014752:Vinyl Chloride; C035384:1,2-dichloroethylene