Characterization of microbial communities in the aqueous phase of a constructed model wetland treating 1,2-dichloroethene-contaminated groundwater

• Published in: FEMS microbiology ecology 2010-04, Vol.72 (1), p.74-88
• Main Authors: Imfeld, Gwenaël, Aragonés, Cristian Estop, Fetzer, Ingo, Mészáros, Éva, Zeiger, Simone, Nijenhuis, Ivonne, Nikolausz, Marcell, Delerce, Sylvain, Richnow, Hans H
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Anoxic conditions; Archaea - classification; Archaea - genetics; Archaea - growth & development; Archaea - metabolism; Artificial wetlands; Bacteria - classification; Bacteria - genetics; Bacteria - growth & development; Bacteria - metabolism; Biodegradation; Biodegradation of pollutants; Biodegradation, Environmental; Biological and medical sciences; Biotechnology; chlorinated ethenes; Communities; Community structure; Composition; compound-specific isotope analysis; Dechlorination; Dehalobacter; Dehalococcoides; DGGE; Dichloroethylenes - analysis; Dichloroethylenes - metabolism; DNA, Bacterial - analysis; Ecology; Electrophoresis; Environment and pollution; Ethene; Ethylene; Ethylenes - metabolism; Fundamental and applied biological sciences. Psychology; Gel electrophoresis; Gene libraries; Gene sequencing; Genes, rRNA; Geobacter; Groundwater; Groundwater pollution; Groundwater treatment; Halogenation; Industrial applications and implications. Economical aspects; Iron Compounds - analysis; Iron Compounds - metabolism; Microbial activity; Microbial ecology; Microbiology; Microbiomes; Microorganisms; ordination methods; Oxidation-Reduction; Phase transitions; Phylogeny; Proteobacteria; rRNA 16S; Sulfides - analysis; Sulfides - metabolism; Various environments (extraatmospheric space, air, water); Vinyl chloride; Vinyl Chloride - metabolism; Water analysis; Water Microbiology; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - metabolism; Water sampling; Wetlands
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1111/j.1574-6941.2009.00825.x

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 ~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.