Dual C–Cl Isotope Analysis for Characterizing the Reductive Dechlorination of α- and γ-Hexachlorocyclohexane by Two Dehalococcoides mccartyi Strains and an Enrichment Culture

2020 ◽  
Vol 54 (12) ◽  
pp. 7250-7260 ◽  
Author(s):  
Yaqing Liu ◽  
Jia Liu ◽  
Julian Renpenning ◽  
Ivonne Nijenhuis ◽  
Hans-Hermann Richnow
Keyword(s):  
Reductive Dechlorination ◽  
Enrichment Culture ◽  
Isotope Analysis ◽  
Dehalococcoides Mccartyi

scholarly journals Complete Genome Sequence of Dehalococcoides mccartyi Strain WBC-2, Capable of Anaerobic Reductive Dechlorination of Vinyl Chloride

2016 ◽  
Vol 4 (6) ◽  
Author(s):  
Olivia Molenda ◽  
Shuiquan Tang ◽  
Elizabeth A. Edwards
Keyword(s):  
Vinyl Chloride ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Reductive Dechlorination ◽  
Complete Genome ◽  
Microbial Consortium ◽  
Enrichment Culture ◽  
Metagenomic Sequencing ◽  
The West ◽  
Dehalococcoides Mccartyi

Dehalococcoides mccartyi strain WBC-2 dechlorinates carcinogen vinyl chloride to ethene in the West Branch Canal Creek (WBC-2) microbial consortium used for bioaugmentation. We assembled and closed the complete genome sequence of this prokaryote using metagenomic sequencing from an enrichment culture.

scholarly journals Acetylene-Fueled Trichloroethene Reductive Dechlorination in a Groundwater Enrichment Culture

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sara Gushgari-Doyle ◽  
Ronald S. Oremland ◽  
Ray Keren ◽  
Shaun M. Baesman ◽  
Denise M. Akob ◽  
...  
Keyword(s):  
Microbial Community ◽  
Reductive Dechlorination ◽  
Enrichment Culture ◽  
The United States ◽  
Degradation Pathway ◽  
Content Type ◽  
Dehalococcoides Mccartyi ◽  
Abiotic Degradation ◽  
Laboratory Microcosm ◽  
Microcosm Studies

ABSTRACT In aquifers, acetylene (C2H2) is a product of abiotic degradation of trichloroethene (TCE) catalyzed by in situ minerals. C2H2 can, in turn, inhibit multiple microbial processes including TCE dechlorination and metabolisms that commonly support dechlorination, in addition to supporting the growth of acetylenotrophic microorganisms. Previously, C2H2 was shown to support TCE reductive dechlorination in synthetic, laboratory-constructed cocultures containing the acetylenotroph Pelobacter sp. strain SFB93 and Dehalococcoides mccartyi strain 195 or strain BAV1. In this study, we demonstrate TCE and perchloroethene (PCE) reductive dechlorination by a microbial community enriched from contaminated groundwater and amended with C2H2 as the sole electron donor and organic carbon source. The metagenome of the stable, enriched community was analyzed to elucidate putative community functions. A novel anaerobic acetylenotroph in the phylum Actinobacteria was identified using metagenomic analysis. These results demonstrate that the coupling of acetylenotrophy and reductive dechlorination can occur in the environment with native bacteria and broaden our understanding of biotransformation at contaminated sites containing both TCE and C2H2. IMPORTANCE Understanding the complex metabolisms of microbial communities in contaminated groundwaters is a challenge. PCE and TCE are among the most common groundwater contaminants in the United States that, when exposed to certain minerals, exhibit a unique abiotic degradation pathway in which C2H2 is a product. C2H2 can act as both an inhibitor of TCE dechlorination and of supporting metabolisms and an energy source for acetylenotrophic bacteria. Here, we combine laboratory microcosm studies with computational approaches to enrich and characterize an environmental microbial community that couples two uncommon metabolisms, demonstrating unique metabolic interactions only yet reported in synthetic, laboratory-constructed settings. Using this comprehensive approach, we have identified the first reported anaerobic acetylenotroph in the phylum Actinobacteria, demonstrating the yet-undescribed diversity of this metabolism that is widely considered to be uncommon.

scholarly journals Effects of the Feeding Solution Composition on a Reductive/Oxidative Sequential Bioelectrochemical Process for Perchloroethylene Removal

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 405
Author(s):  
Edoardo Dell’Armi ◽  
Marco Zeppilli ◽  
Bruna Matturro ◽  
Simona Rossetti ◽  
Marco Petrangeli Papini ◽  
...  
Keyword(s):  
Reductive Dechlorination ◽  
Nitrate Reduction ◽  
Coulombic Efficiency ◽  
Reducing Power ◽  
Mineral Medium ◽  
Process Conditions ◽  
Microbial Electrolysis Cells ◽  
Dehalococcoides Mccartyi ◽  
In Series ◽  
Synthetic Groundwater

Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants due to their improper use in several industrial activities. Specialized microorganisms are able to perform the reductive dechlorination (RD) of high-chlorinated CAHs such as perchloroethylene (PCE), while the low-chlorinated ethenes such as vinyl chloride (VC) are more susceptible to oxidative mechanisms performed by aerobic dechlorinating microorganisms. Bioelectrochemical systems can be used as an effective strategy for the stimulation of both anaerobic and aerobic microbial dechlorination, i.e., a biocathode can be used as an electron donor to perform the RD, while a bioanode can provide the oxygen necessary for the aerobic dechlorination reaction. In this study, a sequential bioelectrochemical process constituted by two membrane-less microbial electrolysis cells connected in series has been, for the first time, operated with synthetic groundwater, also containing sulphate and nitrate, to simulate more realistic process conditions due to the possible establishment of competitive processes for the reducing power, with respect to previous research made with a PCE-contaminated mineral medium (with neither sulphate nor nitrate). The shift from mineral medium to synthetic groundwater showed the establishment of sulphate and nitrate reduction and caused the temporary decrease of the PCE removal efficiency from 100% to 85%. The analysis of the RD biomarkers (i.e., Dehalococcoides mccartyi 16S rRNA and tceA, bvcA, vcrA genes) confirmed the decrement of reductive dechlorination performances after the introduction of the synthetic groundwater, also characterized by a lower ionic strength and nutrients content. On the other hand, the system self-adapted the flowing current to the increased demand for the sulphate and nitrate reduction, so that reducing power was not in defect for the RD, although RD coulombic efficiency was less.

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 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 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 Use of C–Cl CSIA to elucidate origin and fate of DCM in complex contaminated field sites

2019 ◽  
Vol 98 ◽  
pp. 12003
Author(s):  
Natàlia Blázquez-Pallí ◽  
Orfan Shouakar-Stash ◽  
Jordi Palau ◽  
Alba Trueba-Santiso ◽  
Joan Varias ◽  
...  
Keyword(s):  
Field Data ◽  
Enrichment Culture ◽  
Isotope Analysis ◽  
Data Interpretation ◽  
Dual Isotope ◽  
Isotopic Compositions ◽  
The Common ◽  
Microcosm Studies ◽  
Groundwater Pollutant ◽  
Contaminated Field

We used C-Cl dual isotope analysis and microcosm studies for elucidating the origin and fate of the common groundwater pollutant dichloromethane (DCM) in two different multi-contaminant field sites in Catalonia, Spain; where DCM contamination could be the result of direct solvent releases and/or chloroform (CF) transformation. Known commercial solvents isotopic compositions as well as characteristic C-Cl dual isotope slopes from our anaerobic enrichment culture containing Dehalobacterium sp., capable of fermenting DCM, and other bacteria from the literature were used for field data interpretation.

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