scholarly journals Dual Element (C/Cl) Isotope Analysis Indicates Distinct Mechanisms of Reductive Dehalogenation of Chlorinated Ethenes and Dichloroethane in Dehalococcoides mccartyi Strain BTF08 With Defined Reductive Dehalogenase Inventories

2020 ◽  
Vol 11 ◽  
Author(s):  
Steffi Franke ◽  
Katja Seidel ◽  
Lorenz Adrian ◽  
Ivonne Nijenhuis
Keyword(s):  
Isotope Analysis ◽  
Chlorinated Ethenes ◽  
Reductive Dehalogenation ◽  
Reductive Dehalogenase ◽  
Dehalococcoides Mccartyi

scholarly journals Molecular Characterization of the PceA Reductive Dehalogenase of Desulfitobacterium sp. Strain Y51

2002 ◽  
Vol 184 (13) ◽  
pp. 3419-3425 ◽  
Author(s):  
Akiko Suyama ◽  
Masaki Yamashita ◽  
Sadazo Yoshino ◽  
Kensuke Furukawa
Keyword(s):  
Escherichia Coli ◽  
Molecular Characterization ◽  
Specific Activity ◽  
Chlorinated Ethenes ◽  
Reductive Dehalogenation ◽  
Reductive Dehalogenase ◽  
Dna Fragment

ABSTRACT The tetrachloroethene (PCE) reductive dehalogenase (encoded by the pceA gene and designated PceA dehalogenase) of Desulfitobacterium sp. strain Y51 was purified and characterized. The expression of the enzyme was highly induced in the presence of PCE and trichloroethene (TCE). The purified enzyme catalyzed the reductive dehalogenation of PCE via TCE to cis-1,2-dichloroethene at a specific activity of 113.6 nmol · min−1 · mg of protein−1. The apparent Km values for PCE and TCE were 105.7 and 535.3 μM, respectively. Chlorinated ethenes other than PCE and TCE were not dehalogenated. However, the enzyme exhibited dehalogenation activity for various chlorinated ethanes such as hexachloroethane, pentachloroethane, 1,1,1,2-tetrachloroethane, and 1,1,2,2-tetrachloroethane. The pceA gene of Desulfitobacterium sp. strain Y51 was identified in a 2.8-kb DNA fragment and used to express the protein in Escherichia coli for the preparation of antibodies. Immunoblot analyses located PceA in the periplasm of the cell.

scholarly journals Molecular Identification of the Catabolic Vinyl Chloride Reductase from Dehalococcoides sp. Strain VS and Its Environmental Distribution

2004 ◽  
Vol 70 (8) ◽  
pp. 4880-4888 ◽  
Author(s):  
Jochen A. Müller ◽  
Bettina M. Rosner ◽  
Gregory von Abendroth ◽  
Galit Meshulam-Simon ◽  
Perry L. McCarty ◽  
...  
Keyword(s):  
Vinyl Chloride ◽  
Chlorinated Ethenes ◽  
Reductive Dehalogenation ◽  
Predicted Amino Acid Sequence ◽  
Environmental Distribution ◽  
Iron Sulfur Cluster ◽  
Reductive Dehalogenase ◽  
The Family ◽  
Small Hydrophobic Protein

ABSTRACT Reductive dehalogenation of vinyl chloride (VC) to ethene is the key step in complete anaerobic degradation of chlorinated ethenes. VC-reductive dehalogenase was partially purified from a highly enriched culture of the VC-respiring Dehalococcoides sp. strain VS. The enzyme reduced VC and all dichloroethene (DCE) isomers, but not tetrachloroethene (PCE) or trichloroethene (TCE), at high rates. By using reversed genetics, the corresponding gene (vcrA) was isolated and characterized. Based on the predicted amino acid sequence, VC reductase is a novel member of the family of corrinoid/iron-sulfur cluster containing reductive dehalogenases. The vcrA gene was found to be cotranscribed with vcrB, encoding a small hydrophobic protein presumably acting as membrane anchor for VC reductase, and vcrC, encoding a protein with similarity to transcriptional regulators of the NosR/NirI family. The vcrAB genes were subsequently found to be present and expressed in other cultures containing VC-respiring Dehalococcoides organisms and could be detected in water samples from a field site contaminated with chlorinated ethenes. Therefore, the vcrA gene identified here may be a useful molecular target for evaluating, predicting, and monitoring in situ reductive VC dehalogenation.

scholarly journals A Microcosm Treatability Study for Evaluating Wood Mulch-Based Amendments as Electron Donors for Trichloroethene (TCE) Reductive Dechlorination

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1949
Author(s):  
Edoardo Masut ◽  
Alessandro Battaglia ◽  
Luca Ferioli ◽  
Anna Legnani ◽  
Carolina Cruz Viggi ◽  
...  
Keyword(s):  
Electron Donor ◽  
Environmental Sustainability ◽  
Reductive Dechlorination ◽  
Environmental Remediation ◽  
Low Cost ◽  
Chlorinated Solvents ◽  
Electron Donors ◽  
Chlorinated Ethenes ◽  
Dehalococcoides Mccartyi ◽  
Wood Mulch

In this study, wood mulch-based amendments were tested in a bench-scale microcosm experiment in order to assess the treatability of saturated soils and groundwater from an industrial site contaminated by chlorinated ethenes. Wood mulch was tested alone as the only electron donor in order to assess its potential for stimulating the biological reductive dechlorination. It was also tested in combination with millimetric iron filings in order to assess the ability of the additive to accelerate/improve the bioremediation process. The efficacy of the selected amendments was compared with that of unamended control microcosms. The results demonstrated that wood mulch is an effective natural and low-cost electron donor to stimulate the complete reductive dechlorination of chlorinated solvents to ethene. Being a side-product of the wood industry, mulch can be used in environmental remediation, an approach which perfectly fits the principles of circular economy and addresses the compelling needs of a sustainable and low environmental impact remediation. The efficacy of mulch was further improved by the co-presence of iron filings, which accelerated the conversion of vinyl chloride into the ethene by increasing the H2 availability rather than by catalyzing the direct abiotic dechlorination of contaminants. Chemical analyses were corroborated by biomolecular assays, which confirmed the stimulatory effect of the selected amendments on the abundance of Dehalococcoides mccartyi and related reductive dehalogenase genes. Overall, this paper further highlights the application potential and environmental sustainability of wood mulch-based amendments as low-cost electron donors for the biological treatment of chlorinated ethenes.

scholarly journals Extrachromosomal circular elements targeted by CRISPR-Cas in Dehalococcoides mccartyi are linked to mobilization of reductive dehalogenase genes

2018 ◽  
Vol 13 (1) ◽  
pp. 24-38 ◽  
Author(s):  
Olivia Molenda ◽  
Shuiquan Tang ◽  
Line Lomheim ◽  
Vasu K. Gautam ◽  
Sofia Lemak ◽  
...  
Keyword(s):  
Reductive Dehalogenase ◽  
Dehalococcoides Mccartyi ◽  
Reductive Dehalogenase Genes

scholarly journals Transcriptomic and Proteomic Responses of the Organohalide-Respiring Bacterium Desulfoluna spongiiphila to Growth with 2,6-Dibromophenol as the Electron Acceptor

2019 ◽  
Vol 86 (5) ◽  
Author(s):  
Jie Liu ◽  
Lorenz Adrian ◽  
Max M. Häggblom
Keyword(s):  
Gene Expression ◽  
Secondary Metabolites ◽  
Electron Acceptor ◽  
Marine Sponge ◽  
Reductive Dehalogenation ◽  
Important Process ◽  
Organohalide Respiration ◽  
Content Type ◽  
Reductive Dehalogenase ◽  
Significant Difference

ABSTRACT Organohalide respiration is an important process in the global halogen cycle and for bioremediation. In this study, we compared the global transcriptomic and proteomic analyses of Desulfoluna spongiiphila strain AA1, an organohalide-respiring member of the Desulfobacterota isolated from a marine sponge, with 2,6-dibromophenol or with sulfate as an electron acceptor. The most significant difference of the transcriptomic analysis was the expression of one reductive dehalogenase gene cluster (rdh16), which was significantly upregulated with the addition of 2,6-dibromophenol. The corresponding protein, reductive dehalogenase RdhA16032, was detected in the proteome under treatment with 2,6-dibromophenol but not with sulfate only. There was no significant difference in corrinoid biosynthesis gene expression levels between the two treatments, indicating that the production of corrinoid in D. spongiiphila is constitutive or not specific for organohalide versus sulfate respiration. Electron-transporting proteins or mediators unique for reductive dehalogenation were not revealed in our analysis, and we hypothesize that reductive dehalogenation may share an electron-transporting system with sulfate reduction. The metabolism of D. spongiiphila, predicted from transcriptomic and proteomic results, demonstrates high metabolic versatility and provides insights into the survival strategies of a marine sponge symbiont in an environment rich in organohalide compounds and other secondary metabolites. IMPORTANCE Respiratory reductive dehalogenation is an important process in the overall cycling of both anthropogenic and natural organohalide compounds. Marine sponges produce a vast array of bioactive compounds as secondary metabolites, including diverse halogenated compounds that may enrich for dehalogenating bacteria. Desulfoluna spongiiphila strain AA1 was originally enriched and isolated from the marine sponge Aplysina aerophoba and can grow with both brominated compounds and sulfate as electron acceptors for respiration. An understanding of the overall gene expression and the protein production profile in response to organohalides is needed to identify the full complement of genes or enzymes involved in organohalide respiration. Elucidating the metabolic capacity of this sponge-associated bacterium lays the foundation for understanding how dehalogenating bacteria may control the fate of organohalide compounds in sponges and their role in a symbiotic organobromine cycle.

scholarly journals Unexpected Specificity of Interspecies Cobamide Transfer from Geobacter spp. to Organohalide-Respiring Dehalococcoides mccartyi Strains

2012 ◽  
Vol 78 (18) ◽  
pp. 6630-6636 ◽  
Author(s):  
Jun Yan ◽  
Kirsti M. Ritalahti ◽  
Darlene D. Wagner ◽  
Frank E. Löffler
Keyword(s):  
Reductive Dechlorination ◽  
De Novo ◽  
Synthetic Medium ◽  
Geobacter Sulfurreducens ◽  
Rrna Gene ◽  
Content Type ◽  
Reductive Dehalogenase ◽  
Dehalococcoides Mccartyi ◽  
Gene Copies ◽  
Pure Cultures

ABSTRACTDehalococcoides mccartyistrains conserve energy from reductive dechlorination reactions catalyzed by corrinoid-dependent reductive dehalogenase enzyme systems.Dehalococcoideslacks the ability forde novocorrinoid synthesis, and pure cultures require the addition of cyanocobalamin (vitamin B12) for growth. In contrast,Geobacter lovleyi, which dechlorinates tetrachloroethene tocis-1,2-dichloroethene (cis-DCE), and the nondechlorinating speciesGeobacter sulfurreducenshave complete sets of cobamide biosynthesis genes and produced 12.9 ± 2.4 and 24.2 ± 5.8 ng of extracellular cobamide per liter of culture suspension, respectively, during growth with acetate and fumarate in a completely synthetic medium.G. lovleyi-D. mccartyistrain BAV1 or strain FL2 cocultures provided evidence for interspecies corrinoid transfer, andcis-DCE was dechlorinated to vinyl chloride and ethene concomitant withDehalococcoidesgrowth. In contrast, negligible increase inDehalococcoides16S rRNA gene copies and insignificant dechlorination occurred inG. sulfurreducens-D. mccartyistrain BAV1 or strain FL2 cocultures. Apparently,G. lovleyiproduces a cobamide that complementsDehalococcoides' nutritional requirements, whereasG. sulfurreducensdoes not. Interestingly,Dehalococcoidesdechlorination activity and growth could be restored inG. sulfurreducens-Dehalococcoidescocultures by adding 10 μM 5′,6′-dimethylbenzimidazole. Observations made with theG. sulfurreducens-Dehalococcoidescocultures suggest that the exchange of the lower ligand generated a cobalamin, which supportedDehalococcoidesactivity. These findings have implications forin situbioremediation and suggest that the corrinoid metabolism ofDehalococcoidesmust be understood to faithfully predict, and possibly enhance, reductive dechlorination activities.

scholarly journals A Novel Reductive Dehalogenase, Identified in a Contaminated Groundwater Enrichment Culture and in Desulfitobacterium dichloroeliminans Strain DCA1, Is Linked to Dehalogenation of 1,2-Dichloroethane

2007 ◽  
Vol 73 (9) ◽  
pp. 2990-2999 ◽  
Author(s):  
Massimo Marzorati ◽  
Francesca de Ferra ◽  
Hilde Van Raemdonck ◽  
Sara Borin ◽  
Elena Allifranchini ◽  
...  
Keyword(s):  
Amino Acid ◽  
Gene Cluster ◽  
Enrichment Culture ◽  
Gene Copy Number ◽  
Gene Clusters ◽  
Amino Acid Identity ◽  
Chlorinated Ethenes ◽  
Gene Copy ◽  
Direct Pcr ◽  
Reductive Dehalogenase

ABSTRACT A mixed culture dechlorinating 1,2-dichloroethane (1,2-DCA) to ethene was enriched from groundwater that had been subjected to long-term contamination. In the metagenome of the enrichment, a 7-kb reductive dehalogenase (RD) gene cluster sequence was detected by inverse and direct PCR. The RD gene cluster had four open reading frames (ORF) showing 99% nucleotide identity with pceB, pceC, pceT, and orf1 of Dehalobacter restrictus strain DSMZ 9455T, a bacterium able to dechlorinate chlorinated ethenes. However, dcaA, the ORF encoding the catalytic subunit, showed only 94% nucleotide and 90% amino acid identity with pceA of strain DSMZ 9455T. Fifty-three percent of the amino acid differences were localized in two defined regions of the predicted protein. Exposure of the culture to 1,2-DCA and lactate increased the dcaA gene copy number by 2 log units, and under these conditions the dcaA and dcaB genes were actively transcribed. A very similar RD gene cluster with 98% identity in the dcaA gene sequence was identified in Desulfitobacterium dichloroeliminans strain DCA1, the only known isolate that selectively dechlorinates 1,2-DCA but not chlorinated ethenes. The dcaA gene of strain DCA1 possesses the same amino acid motifs as the new dcaA gene. Southern hybridization using total genomic DNA of strain DCA1 with dcaA gene-specific and dcaB- and pceB-targeting probes indicated the presence of two identical or highly similar dehalogenase gene clusters. In conclusion, these data suggest that the newly described RDs are specifically adapted to 1,2-DCA dechlorination.

Sign in / Sign up

Export Citation Format

Share Document