Project description:A functional microarray targeting 24 genes involved in chlorinated solvent biodegradation pathways has been developed and used to monitor the gene diversity present in four trichloroethylene (TCE) contaminated sites under ERD (enhanced reductive dechlorination) treatment. The microarray format provided by NimbleGen and used in this study is 12x135K. 2 µg of labelled gDNA from 30 groundwater samples were hybridized on the microarrays.
Project description:This SuperSeries is composed of the following subset Series: GSE28606: Monitoring of functional gene responses to ERD (enhanced reductive dechlorination) from four TCE-contaminated sites GSE28608: Monitoring of functional gene responses to biostimulation from a TCE-contaminated site Refer to individual Series
Project description:Microbial reductive dechlorination of trichloroethene (TCE) in groundwater often results in the accumulation of dichloroethenes (DCEs). Dehalococcoides mccartyi (Dhc) are the only known bacteria capable of dechlorination beyond DCE to non-toxic ethene. In this study, two newly isolated Dhc strains (11a and 11a5) with dissimilar functional abilities are described. Strain 11a reductively dechlorinates TCE, 1,1-DCE, cis-DCE, trans-DCE, and vinyl chloride (VC) to ethene, while strain 11a5 dechlorinates TCE and all three DCE isomers only to VC. Each of these dechlorination reactions are coupled to growth by these strains. The VC dechlorination rate of strain 11a occurs at a rate of 258 nmol per min per mg of protein, about two times faster than previously reported stains. Strain 11a possesses the vcrA gene while strain 11a5 contains the tceA gene. Strains 11a and 11a5 share 100% 16S rRNA gene sequence identity with previously sequenced Dhc strains BAV1 and CBDB1, placing it within the Pinellas subgroup, and 85.4% and 89.5% of all genes present in the CBDB1 and BAV1 genomes were detected in strains 11a and 11a5, respectively, using a custom-designed microarray targeting four sequenced Dhc strains. Genes that were not detected in strains 11a and 11a5 are mostly within the high plasticity regions or integrated elements of the sequenced strains. This study reports the functional description and comparative genomics of two additional Dhc isolates and provides evidence that the observed functional incongruence between the activity and core genome phylogenies of Dhc strains is likely driven by the horizontal transfer of key reductive dehalogenase-encoding genes.
Project description:A functional microarray targeting 24 genes involved in chlorinated solvent biodegradation pathways has been developed and used to monitor the gene expression in a contaminated site (site B) under ERD (enhanced reductive dechlorination) treatment. The microarray format provided by NimbleGen and used in this study is 12x135K. 4 µg of labelled antisense mRNA from 3 groundwater samples were hybridized on the microarray.
2012-04-03 | GSE28608 | GEO
Project description:Acetylene-fueled TCE reductive dechlorination in a groundwater enrichment culture
Project description:A functional microarray targeting 24 genes involved in chlorinated solvent biodegradation pathways has been developed and used to monitor the gene diversity present in four trichloroethylene (TCE) contaminated sites under ERD (enhanced reductive dechlorination) treatment. The microarray format provided by NimbleGen and used in this study is 12x135K. 2 M-BM-5g of labelled gDNA from 30 groundwater samples were hybridized on the microarrays. A 30-chip study was performed, each chip corresponding to hybridization with 2 M-BM-5g of labelled gDNA retrieved from a monitoring well from one of the four contaminated sites. Each probe (760nt) on the microarray was synthesized in eight replicates, and a total of 5,707 random probes was used to determine the background noise. Groundwater samples were collected from four contaminated sites (B, F, G and H), four monitoring wells per site (P1, P2, P3 and P4). P1: well located upstream to the contamination source. P2: well in the contamination source. P3 and P4: wells located downstream to the contamination source. For site B, the monitoring of ERD demonstration was performed through a total of 5 sampling campaigns: C1 (T=0), C2 (T=104 days), C3 (T=231 days), C4 (T=291 days) and C5 (T=378 days). For the three other sites (F, G and H), only one sampling campaign was performed after the treatment.
Project description:Bacteria of the group “Dehalococcoides” display the ability to respire recalcitrant chlorinated organic compounds in laboratory and field site applications. Though reductive dehalogenases (RDases) have been shown to directly catalyze dechlorination reactions, the respiratory pathways and function of most genome-encoded RDases in Dehalococcoides strains remain incompletely described. In order to broaden the understanding of the biological organization of “Dehalococcoides”, this study monitored the trancriptomic response of “Dehalococcoides ethenogenes” stain 195 through microarray technology. Batch versus continuously fed cultures were examined and compared. When similarly respiring (~120 μeeq PCE/(L-hr)) batch and pseudo steady-state cultures were contrasted, the reductive dehalogenases (RDases) DET1545 and DET0180 were up-regulated in the PSS system indicating their activity at lower overall electron acceptor concentration.
