Concurrent Ethene Generation and Growth ofDehalococcoidesContaining Vinyl Chloride Reductive Dehalogenase Genes During an Enhanced Reductive Dechlorination Field Demonstration

2008 ◽  
Vol 42 (24) ◽  
pp. 9302-9309 ◽  
Author(s):  
Charlotte Scheutz ◽  
Neal d. Durant ◽  
Philip Dennis ◽  
Maria Heisterberg Hansen ◽  
Torben Jørgensen ◽  
...  
Keyword(s):  
Vinyl Chloride ◽  
Reductive Dechlorination ◽  
Reductive Dehalogenase ◽  
Reductive Dehalogenase Genes ◽  
Enhanced Reductive Dechlorination

scholarly journals Genome Sequence of “Candidatus Dehalogenimonas etheniformans” Strain GP, a Vinyl Chloride-Respiring Anaerobe

2020 ◽  
Vol 9 (50) ◽  
Author(s):  
Yi Yang ◽  
Jun Yan ◽  
Xiuying Li ◽  
Yan Lv ◽  
Yiru Cui ◽  
...  
Keyword(s):  
Vinyl Chloride ◽  
Genome Sequence ◽  
Reductive Dechlorination ◽  
Reductive Dehalogenase ◽  
Reductive Dehalogenase Genes

ABSTRACT “Candidatus Dehalogenimonas etheniformans” strain GP couples growth with the reductive dechlorination of vinyl chloride and several polychlorinated ethenes. The genome sequence comprises a circular 2.07-Mb chromosome with a G+C content of 51.9% and harbors 50 putative reductive dehalogenase genes.

scholarly journals Genetic Identification of a Putative Vinyl Chloride Reductase in Dehalococcoides sp. Strain BAV1

2004 ◽  
Vol 70 (10) ◽  
pp. 6347-6351 ◽  
Author(s):  
Rosa Krajmalnik-Brown ◽  
Tina Hölscher ◽  
Ivy N. Thomson ◽  
F. Michael Saunders ◽  
Kirsti M. Ritalahti ◽  
...  
Keyword(s):  
Vinyl Chloride ◽  
Reductive Dechlorination ◽  
Complete Sequence ◽  
Mixed Cultures ◽  
Genetic Identification ◽  
Degenerate Primers ◽  
Transcription Analysis ◽  
Reductive Dehalogenase ◽  
Conserved Regions ◽  
Rdase Genes

ABSTRACT Dehalococcoides sp. strain BAV1 couples growth with the reductive dechlorination of vinyl chloride (VC) to ethene. Degenerate primers targeting conserved regions in reductive dehalogenase (RDase) genes were designed and used to PCR amplify putative RDase genes from strain BAV1. Seven unique RDase gene fragments were identified. Transcription analysis of VC-grown BAV1 cultures suggested that bvcA was involved in VC reductive dechlorination, and the complete sequence of bvcA was obtained. bvcA was absent in Dehalococcoides isolates that failed to respire VC, yet was detected in four of eight VC-respiring mixed cultures.

scholarly journals Complete Genome Sequence of Dehalococcoides mccartyi Strain FL2, a Trichloroethene-Respiring Anaerobe Isolated from Pristine Freshwater Sediment

2019 ◽  
Vol 8 (33) ◽  
Author(s):  
Jun Yan ◽  
Yi Yang ◽  
Xiuying Li ◽  
Frank E. Löffler
Keyword(s):  
Complete Genome Sequence ◽  
Reductive Dechlorination ◽  
Complete Genome ◽  
Hydrogen Oxidation ◽  
Protein Coding ◽  
Coding Sequences ◽  
Content Type ◽  
Reductive Dehalogenase ◽  
Dehalococcoides Mccartyi ◽  
Reductive Dehalogenase Genes

Dehalococcoides mccartyi strain FL2 couples growth to hydrogen oxidation and reductive dechlorination of trichloroethene and cis- and trans-1,2-dichloroethenes. Strain FL2 has a 1.42-Mb genome with a G+C content of 47.0% and carries 1,465 protein-coding sequences, including 24 reductive dehalogenase genes.

scholarly journals Expression of Reductive Dehalogenase Genes in Dehalococcoides ethenogenes Strain 195 Growing on Tetrachloroethene, Trichloroethene, or 2,3-Dichlorophenol

2007 ◽  
Vol 73 (14) ◽  
pp. 4439-4445 ◽  
Author(s):  
Jennifer M. Fung ◽  
Robert M. Morris ◽  
Lorenz Adrian ◽  
Stephen H. Zinder
Keyword(s):  
Reductive Dechlorination ◽  
Stop Codon ◽  
Gene Transcript ◽  
High Coverage ◽  
Transcript Levels ◽  
Reductive Dehalogenase ◽  
Dehalococcoides Ethenogenes ◽  
Rd Cells ◽  
Reductive Dehalogenase Genes ◽  
In Cells

ABSTRACT Reductive dehalogenase (RD) gene transcript levels in Dehalococcoides ethenogenes strain 195 were investigated using reverse transcriptase quantitative PCR during growth and reductive dechlorination of tetrachloroethene (PCE), trichloroethene (TCE), or 2,3-dichlorophenol (2,3-DCP). Cells grown with PCE or TCE had high transcript levels (greater than that for rpoB) for tceA, which encodes the TCE RD, pceA, which encodes the PCE RD, and DET0162, which contains a predicted stop codon and is considered nonfunctional. In cells grown with 2,3-DCP, tceA mRNA was less than 1% of that for rpoB, indicating that its transcription was regulated. pceA and DET0162 were the only RD genes with high transcript levels in cells grown with 2,3-DCP. Proteomic analysis of PCE-grown cells detected both PceA and TceA with high peptide coverage but not DET0162, and analysis of 2,3-DCP-grown cells detected PceA with high coverage but not TceA, DET0162, or any other potential RD. Cells grown with PCE or 2,3-DCP were tested for the ability to dechlorinate PCE, TCE, or 2,3-DCP with H2 as the electron donor. 2,3-DCP-grown cells were unable to dechlorinate TCE but dechlorinated PCE to TCE without a lag, and PCE-grown cells dechlorinated 2,3-DCP without a lag. These results show that 2,3-DCP-grown cells do not produce TceA and that DET0162 is transcribed but its translation product is not detectable in cells and are consistent with PceA's being bifunctional, also serving as the 2,3-DCP RD. Chlorophenols naturally occur in soils and are good candidates for the original substrates for PceA.

scholarly journals Multiple Reductive-Dehalogenase-Homologous Genes Are Simultaneously Transcribed during Dechlorination by Dehalococcoides-Containing Cultures

2005 ◽  
Vol 71 (12) ◽  
pp. 8257-8264 ◽  
Author(s):  
Alison S. Waller ◽  
Rosa Krajmalnik-Brown ◽  
Frank E. Löffler ◽  
Elizabeth A. Edwards
Keyword(s):  
Vinyl Chloride ◽  
Electron Acceptor ◽  
Reductive Dechlorination ◽  
Amino Acid Identity ◽  
Degenerate Primers ◽  
Acid Identity ◽  
Reductive Dehalogenase ◽  
Homologous Genes ◽  
Differential Transcription ◽  
Transcribed Sequences

ABSTRACT Degenerate primers were used to amplify 14 distinct reductive-dehalogenase-homologous (RDH) genes from the Dehalococcoides-containing mixed culture KB1. Most of the corresponding predicted proteins were highly similar (97 to >99% amino acid identity) to previously reported Dehalococcoides reductive dehalogenases. To examine the differential transcription of these RDH genes, KB1 was split into five subcultures amended with either trichloroethene, cis-1,2-dichloroethene, vinyl chloride, 1,2-dichlorethane, or no chlorinated electron acceptor. Total RNA was extracted following the onset of reductive dechlorination, and RDH transcripts were reverse transcribed and amplified using degenerate primers. The results indicate that the transcription of RDH genes requires the presence of a chlorinated electron acceptor, and for all treatments, multiple RDH genes were simultaneously transcribed, with transcripts of two of the genes being present under all four electron-accepting conditions. Two of the transcribed sequences were highly similar to reported vinyl chloride reductase genes, namely, vcrA from Dehalococcoides sp. strain VS and bvcA from Dehalococcoides sp. strain BAV1. These findings suggest that multiple RDH genes are induced by a single chlorinated substrate and that multiple reductive dehalogenases contribute to chloroethene degradation in KB1.

Reductive Dechlorination of Chlorinated Ethenes and 1,2-Dichloroethane by “Dehalococcoides ethenogenes” 195

1999 ◽  
Vol 65 (7) ◽  
pp. 3108-3113 ◽  
Author(s):  
Xavier Maymó-Gatell ◽  
Timothy Anguish ◽  
Stephen H. Zinder
Keyword(s):  
Vinyl Chloride ◽  
Growth Medium ◽  
Electron Acceptor ◽  
Reductive Dechlorination ◽  
Electron Acceptors ◽  
Chlorinated Compounds ◽  
Reductive Dehalogenase ◽  
Dehalococcoides Ethenogenes ◽  
Over Time ◽  
Number Of Cells

ABSTRACT “Dehalococcoides ethenogenes” 195 can reductively dechlorinate tetrachloroethene (PCE) completely to ethene (ETH). When PCE-grown strain 195 was transferred (2% [vol/vol] inoculum) into growth medium amended with trichloroethene (TCE),cis-dichloroethene (DCE), 1,1-DCE, or 1,2-dichloroethane (DCA) as an electron acceptor, these chlorinated compounds were consumed at increasing rates over time, which indicated that growth occurred. Moreover, the number of cells increased when TCE, 1,1-DCE, or DCA was present. PCE, TCE, 1,1-DCE, and cis-DCE were converted mainly to vinyl chloride (VC) and then to ETH, while DCA was converted to ca. 99% ETH and 1% VC. cis-DCE was used at lower rates than PCE, TCE, 1,1-DCE, or DCA was used. When PCE-grown cultures were transferred to media containing VC ortrans-DCE, products accumulated slowly, and there was no increase in the rate, which indicated that these two compounds did not support growth. When the intermediates in PCE dechlorination by strain 195 were monitored, TCE was detected first, followed bycis-DCE. After a lag, VC, 1,1-DCE, andtrans-DCE accumulated, which is consistent with the hypothesis that cis-DCE is the precursor of these compounds. Both cis-DCE and 1,1-DCE were eventually consumed, and both of these compounds could be considered intermediates in PCE dechlorination, whereas the small amount oftrans-DCE that was produced persisted. Cultures grown on TCE, 1,1-DCE, or DCA could immediately dechlorinate PCE, which indicated that PCE reductive dehalogenase activity was constitutive when these electron acceptors were used.

scholarly journals Complete Genome Sequence of Sulfurospirillum sp. Strain ACSDCE, an Anaerobic Bacterium That Respires Tetrachloroethene under Acidic pH Conditions

2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Yi Yang ◽  
Leitao Huo ◽  
Xiuying Li ◽  
Jun Yan ◽  
Frank E. Löffler
Keyword(s):  
Genome Sequence ◽  
Reductive Dechlorination ◽  
Anaerobic Bacterium ◽  
Acidic Ph ◽  
Protein Coding ◽  
Coding Sequences ◽  
Reductive Dehalogenase ◽  
Ph Values ◽  
Ph Conditions ◽  
Reductive Dehalogenase Genes

ABSTRACT Sulfurospirillum sp. strain ACSDCE couples growth with reductive dechlorination of tetrachloroethene to cis-1,2-dichloroethene at pH values as low as 5.5. The genome sequence of strain ACSDCE consists of a circular 2,737,849-bp chromosome and a 39,868-bp plasmid and carries 2,737 protein-coding sequences, including two reductive dehalogenase genes.

scholarly journals Auxiliary Substrates for Elimination of Trichloroethene, Monochlorobenzene, and Benzene in a Sequential Anaerobic–Aerobic GAC Biobarrier

2007 ◽  
Vol 7 (1 & 2) ◽  
pp. 68
Author(s):  
M. Gozan ◽  
A. Mueller ◽  
A. Tiehm
Keyword(s):  
Vinyl Chloride ◽  
Reductive Dechlorination ◽  
Biological Degradation ◽  
Anaerobic Conditions ◽  
Batch Studies ◽  
Second Stage ◽  
Competitive Reactions ◽  
Novel Concept ◽  
Tce Degradation ◽  
Granulated Activated Carbon

Sequential anaerobic-aerobic barrier is a novel concept for groundwater bioremediation. Trichloroethene (TCE), monochlorobenzene (MCB), and benzene (BZ) were used as model contaminants representing contaminant cocktails frequently found in the contaminated subsurface. The autochthonous microflora from a contaminated field was inoculated to eliminate model contaminants in a set of sequential anaerobic–aerobic granulated activated carbon (GAC) columns and batch studies. In the anaerobic column, the TCE was reductively dechlorinated through cis-dichloroethene (cis-DCE), vinyl chloride (VC), and ethene (ETH). Ethanol and sucrose as auxiliary substrates were added to donate electrons. In the second stage, MCB, BZ, and the lower chlorinated metabolites of TCE degradation, i.e. cis-Dichloroethene (cisDCE) and vinyl chloride (VC), were oxidatively degraded with addition of hydrogen peroxide and nitrate. This paper examines the influence of auxiliary substrates on the biological degradation of model pollutants. In the anaerobic barrier, the auxiliary substrates supply should be maintained low but stoichiometrically adequate for supporting reductive dechlorination. Supplying higher amount of auxiliary substrates provoked competitive reactions in anaerobic conditions, such as sulfate reduction and methanogenesis. If the auxiliary substrates are not utilized completely in the anaerobic phase, the remaining compounds flow into the aerobic phase. This led to unwanted conditions, i.e. oxidation of auxiliary substrates instead of pollutant elimination, and a higher consumption of electron acceptors. In the aerobic barrier, in particular, ethene proved to be a suitable auxiliary substrate for cometabolic degradation of cisDCE.

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