1 Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark2 Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark3 CFB - Metagenomic Systems Biology, Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark4 Department of Environmental Engineering, Technical University of Denmark5 Residual Resource Engineering, Department of Environmental Engineering, Technical University of Denmark6 Water Resources Engineering, Department of Environmental Engineering, Technical University of Denmark7 Department of Systems Biology, Technical University of Denmark8 Office for Study Programmes and Student Affairs, Administration, Technical University of Denmark9 Geological Survey of Denmark and Greenland10 University of Copenhagen11 Geological Survey of Denmark and Greenland
We used current knowledge of cellular processes involved in reductive dechlorination to develop a conceptual model to describe the regulatory system of dechlorination at the cell level; the model links bacterial growth and substrate consumption to the abundance of messenger RNA of functional genes involved in the dechlorination process. The applicability of the model was tested on a treatability study of biostimulated and bioaugmented microcosms. Using quantitative real time PCR, high-resolution expression profiles of the functional reductive dehalogenase genes bvcA and vcrA were obtained during two consecutive dechlorination events of trichlorethene, cis-dichlorethene and vinyl chloride. Up-regulation of the bvcA (for the biostimulated microcosms) and vcrA (for the bioaugmented microcosms) gene expression fitted well with high rates of dechlorination of vinyl chloride, while no known transcripts could be measured during trichloroethene and cis-dichlorethene dechlorination. Maximum concentrations of 2.1 and 1.7 transcripts per gene of the bvcA and vcrA genes, respectively, were measured at the same time points as maximum dechlorination rates were observed. The developed model compared well with the experimental data for both biostimulated and bioaugmented microcosms under non-steady state conditions and was supported by results from a recently published study under steady state conditions.
Water Research, 2013, Vol 47, Issue 7, p. 2467-2478