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Dehalococcoides

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https://www.readbyqxmd.com/read/28919889/dehalococcoides-as-a-potential-biomarker-evidence-for-uncharacterized-organohalides-in-environmental-samples
#1
Qihong Lu, Ling Yu, Zhiwei Liang, Qingyun Yan, Zhili He, Tiangang Luan, Dawei Liang, Shanquan Wang
The massive production and improper disposal of organohalides resulted in worldwide contamination in soil and water. However, their environmental survey based on chromatographic methods was hindered by challenges in testing the extremely wide variety of organohalides. Dehalococcoides as obligate organohalide-respiring bacteria exclusively use organohalides as electron acceptors to support their growth, of which the presence could be coupled with organohalides and, therefore, could be employed as a biomarker of the organohalide pollution...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28914537/coupling-bioflocculation-of-dehalococcoides-mccartyi-to-high-rate-reductive-dehalogenation-of-chlorinated-ethenes
#2
Anca G Delgado, Devyn Fajardo-Williams, Emily Bondank, Sofia Esquivel-Elizondo, Rosa Krajmalnik-Brown
Continuous bioreactors operated at low hydraulic retention times have rarely been explored for reductive dehalogenation of chlorinated ethenes. The inability to consistently develop such bioreactors affects the way growth approaches for Dehalococcoides mccartyi bioaugmentation cultures are envisioned. It also affects interpretation of results from in situ continuous treatment processes. We report bioreactor performance and dehalogenation kinetics of a D. mccartyi-containing consortium in an upflow bioreactor...
September 15, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28894752/identification-of-multiple-dehalogenase-genes-involved-in-tetrachloroethene-to-ethene-dechlorination-in-a-dehalococcoides-dominated-enrichment-culture
#3
Mohamed Ismaeil, Naoko Yoshida, Arata Katayama
Chloroethenes (CEs) are widespread groundwater toxicants that are reductively dechlorinated to nontoxic ethene (ETH) by members of Dehalococcoides. This study established a Dehalococcoides-dominated enrichment culture (designated "YN3") that dechlorinates tetrachloroethene (PCE) to ETH with high dechlorination activity, that is, complete dechlorination of 800 μM PCE to ETH within 14 days in the presence of Dehalococcoides species at 5.7 ± 1.9 × 10(7) copies of 16S rRNA gene/mL. The metagenome of YN3 harbored 18 rdhA genes (designated YN3rdhA1-18) encoding the catalytic subunit of reductive dehalogenase (RdhA), four of which were suggested to be involved in PCE-to-ETH dechlorination based on significant increases in their transcription in response to CE addition...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28843895/dechlorinating-bacteria-are-abundant-but-anaerobic-dechlorination-of-weathered-polychlorinated-dibenzo-p-dioxins-and-dibenzofurans-in-contaminated-sediments-is-limited
#4
Sanna Mäntynen, Anna-Lea Rantalainen, Max M Häggblom
The potential for microbial dechlorination of the weathered polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) was determined in sediments with historical contamination by the chlorophenol wood preservative Ky-5 and its associated dimeric impurities. Sediments were collected from four sites of the Kymijoki River in South-Eastern Finland located at 0, 20, 30, and 60 km downstream from the source of contamination, and at a reference site. We examined the congener profiles of historical PCDD/Fs, including non-2,3,7,8-substituted congeners, and determined the dechlorination potential in sediments at the different sites of the river...
August 24, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28809851/grape-pomace-compost-harbors-organohalide-respiring-dehalogenimonas-species-with-novel-reductive-dehalogenase-genes
#5
Yi Yang, Steven A Higgins, Jun Yan, Burcu Şimşir, Karuna Chourey, Ramsunder Iyer, Robert L Hettich, Brett Baldwin, Dora M Ogles, Frank E Löffler
Organohalide-respiring bacteria have key roles in the natural chlorine cycle; however, most of the current knowledge is based on cultures from contaminated environments. We demonstrate that grape pomace compost without prior exposure to chlorinated solvents harbors a Dehalogenimonas (Dhgm) species capable of using chlorinated ethenes, including the human carcinogen and common groundwater pollutant vinyl chloride (VC) as electron acceptors. Grape pomace microcosms and derived solid-free enrichment cultures were able to dechlorinate trichloroethene (TCE) to less chlorinated daughter products including ethene...
August 15, 2017: ISME Journal
https://www.readbyqxmd.com/read/28803405/pcb-dechlorination-hotspots-and-reductive-dehalogenase-genes-in-sediments-from-a-contaminated-wastewater-lagoon
#6
Timothy E Mattes, Jessica M Ewald, Yi Liang, Andres Martinez, Andrew Awad, Patrick Richards, Keri C Hornbuckle, Jerald L Schnoor
Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants that are distributed worldwide. Although industrial PCB production has stopped, legacy contamination can be traced to several different commercial mixtures (e.g., Aroclors in the USA). Despite their persistence, PCBs are subject to naturally occurring biodegradation processes, although the microbes and enzymes involved are poorly understood. The biodegradation potential of PCB-contaminated sediments in a wastewater lagoon located in Virginia (USA) was studied...
August 12, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28777963/biochar-accelerates-microbial-reductive-debromination-of-2-2-4-4-tetrabromodiphenyl-ether-bde-47-in-anaerobic-mangrove-sediments
#7
Juan Chen, Chao Wang, Ying Pan, Shazia Shyla Farzana, Nora Fung-Yee Tam
A common congener of polybrominated diphenyl ethers, 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), is a prevalent, persistent and toxic pollutant. It could be removed by reduction debromination by microorganisms but the rate is often slow. The study hypothesized that spent mushroom substrate derived biochar amendment could accelerate the microbial reductive debromination of BDE-47 in anaerobic mangrove sediment slurries and evaluated the mechanisms behind. At the end of 20-week experiment, percentages of residual BDE-47 in slurries amended with biochar were significantly lower but debromination products were higher than those without biochar...
July 28, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28764859/modeling-3d-csia-data-carbon-chlorine-and-hydrogen-isotope-fractionation-during-reductive-dechlorination-of-tce-to-ethene
#8
Boris M Van Breukelen, Héloïse A A Thouement, Philip E Stack, Mindy Vanderford, Paul Philp, Tomasz Kuder
Reactive transport modeling of multi-element, compound-specific isotope analysis (CSIA) data has great potential to quantify sequential microbial reductive dechlorination (SRD) and alternative pathways such as oxidation, in support of remediation of chlorinated solvents in groundwater. As a key step towards this goal, a model was developed that simulates simultaneous carbon, chlorine, and hydrogen isotope fractionation during SRD of trichloroethene, via cis-1,2-dichloroethene (and trans-DCE as minor pathway), and vinyl chloride to ethene, following Monod kinetics...
September 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28738864/identification-of-two-organohalide-respiring-dehalococcoidia-associated-to-different-dechlorination-activities-in-pcb-impacted-marine-sediments
#9
Andrea Nuzzo, Andrea Negroni, Giulio Zanaroli, Fabio Fava
BACKGROUND: Microbial reductive dechlorination of polychlorinated biphenyls (PCBs) plays a major role in detoxifying anoxic contaminated freshwater and marine sediments from PCBs. Known members of the phylum Chloroflexi are typically responsible for this activity in freshwater sediments, whereas less is known about the microorganisms responsible for this activity in marine sediments. PCB-respiring activities were detected in PCB-impacted marine sediments of the Venice Lagoon. The aim of this work was to identify the indigenous organohalide-respiring microorganisms in such environments and assess their dechlorination specificity against spiked Aroclor™ 1254 PCBs under laboratory conditions resembling the in situ biogeochemistry...
July 24, 2017: Microbial Cell Factories
https://www.readbyqxmd.com/read/28672697/stratification-of-chlorinated-ethenes-natural-attenuation-in-an-alluvial-aquifer-assessed-by-hydrochemical-and-biomolecular-tools
#10
Jan Němeček, Iva Dolinová, Jiřina Macháčková, Roman Špánek, Alena Ševců, Tomáš Lederer, Miroslav Černík
Biomolecular and hydrochemical tools were used to evaluate natural attenuation of chlorinated ethenes in a Quaternary alluvial aquifer located close to a historical source of large-scale tetrachloroethylene (PCE) contamination. Distinct stratification of redox zones was observed, despite the aquifer's small thickness (2.8 m). The uppermost zone of the target aquifer was characterised by oxygen- and nitrate-reducing conditions, with mixed iron- to sulphate-reducing conditions dominant in the lower zone, along with indications of methanogenesis...
October 2017: Chemosphere
https://www.readbyqxmd.com/read/28665587/organohalide-respiration-with-chlorinated-ethenes-under-low-ph-conditions
#11
Yi Yang, Natalie L Cápiro, Tyler F Marcet, Jun Yan, Kurt D Pennell, Frank E Löffler
Bioremediation at chlorinated solvent sites often leads to groundwater acidification due to electron donor fermentation and enhanced dechlorination activity. The microbial reductive dechlorination process is robust at circumneutral pH, but activity declines at groundwater pH values below 6.0. Consistent with this observation, the activity of tetrachloroethene (PCE) dechlorinating cultures declined at pH 6.0 and was not sustained in pH 5.5 medium, with one notable exception. Sulfurospirillum multivorans dechlorinated PCE to cis-1,2-dichloroethene (cDCE) in pH 5...
July 24, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28631290/a-h2-oxidizing-1-2-3-trichlorobenzene-reducing-multienzyme-complex-isolated-from-the-obligately-organohalide-respiring-bacterium-dehalococcoides-mccartyi-strain-cbdb1
#12
Stefanie Hartwig, Nadya Dragomirova, Anja Kublik, Dominique Türkowsky, Martin von Bergen, Ute Lechner, Lorenz Adrian, R Gary Sawers
Dehalococcoides mccartyi is a small, slow-growing bacterium of the phylum Chloroflexi that conserves energy using aliphatic and aromatic organohalides as electron acceptors, and hydrogen as sole electron donor. A recent study identified a protein complex in the membrane of strain CBDB1 comprising a Hup hydrogenase, a complex iron-sulphur molybdoprotein and a reductive dehalogenase (RdhA) that catalyses reduction of 1,2,3,4-tetrachlorobenzene. Using a combination of size-exclusion chromatography, in-gel hydrogenase activity-staining, immunological analysis and mass spectrometry, we identified here a large molecular mass protein complex solubilized from the cytoplasmic membrane of D...
June 19, 2017: Environmental Microbiology Reports
https://www.readbyqxmd.com/read/28629104/efficient-2-4-dichloronitrobenzene-removal-in-the-coupled-bes-uasb-reactor-effect-of-external-voltage-mode
#13
Hui Chen, Xinyi Gao, Caiqin Wang, Junjie Shao, Xiangyang Xu, Liang Zhu
In this study, bioelectrochemical-upflow anaerobic sludge blanket (BES-UASB) system was developed for treatment of 2,4-dichloronitrobenzen (DClNB) containing wastewater to investigate the effect of external voltage with different supplying modes. Results showed that 2,4-dichloroaniline (DClAN) was under detection limit in R1 (applied with intermittent voltage) and R2 (applied with continuous voltage) when the DClNB loading increased from 25 to 100gm(3)d(-1) (hydraulic retention time (HRT) was decreased from 24 to 6h) while sudden accumulation of DClAN (1...
October 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28618081/loss-of-the-ssra-genome-island-led-to-partial-debromination-in-the-pbde-respiring-dehalococcoides-mccartyi-strain-gy50
#14
Chang Ding, Matthew J Rogers, Kun-Lin Yang, Jianzhong He
Polybrominated diphenyl ethers (PBDEs), chemicals commonly used as flame-retardants in consumer products, are emerging persistent organic pollutants that are ubiquitous in the environment. In this study, we report a PBDE-respiring isolate - Dehalococcoides mccartyi strain GY50, which debrominates the most toxic tetra- and penta-BDE congeners (∼1.4 µM) to diphenyl ether within 12 days with hydrogen as the electron donor. The complete genome sequence revealed 26 reductive dehalogenase homologous genes (rdhAs), among which three genes (pbrA1, pbrA2 and pbrA3) were highly expressed during PBDE debromination...
June 15, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28533514/isolation-and-genomic-characterization-of-a-dehalococcoides-strain-suggests-genomic-rearrangement-during-culture
#15
Masafumi Yohda, Kentaro Ikegami, Yuto Aita, Mizuki Kitajima, Ayane Takechi, Megumi Iwamoto, Tomomi Fukuda, Noriyoshi Tamura, Junji Shibasaki, Seiji Koike, Daisuke Komatsu, Sakari Miyagi, Minoru Nishimura, Yoshihito Uchino, Akino Shiroma, Makiko Shimoji, Hinako Tamotsu, Noriko Ashimine, Misuzu Shinzato, Shun Ohki, Kazuma Nakano, Kuniko Teruya, Kazuhito Satou, Takashi Hirano, Osami Yagi
We have developed and characterized a bacterial consortium that reductively dechlorinates trichloroethene to ethene. Quantitative PCR analysis for the 16S rRNA and reductive dehalogenase genes showed that the consortium is highly enriched with Dehalococcoides spp. that have two vinyl chloride reductive dehalogenase genes, bvcA and vcrA, and a trichloroethene reductive dehalogenase gene, tceA. The metagenome analysis of the consortium by the next generation sequencer SOLiD 3 Plus suggests that a Dehalococcoides sp...
May 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28431359/reconstruction-of-microbial-community-structures-as-evidences-for-soil-redox-coupled-reductive-dechlorination-of-pcp-in-a-mangrove-soil
#16
Yan Xu, Yan He, Xianjin Tang, Philip C Brookes, Jianming Xu
The aim was to investigate the influence of pentachlorophenol (PCP) on the soil microbial communities and the coupled mechanism between PCP reductive dechlorination and soil redox under anaerobic condition. Accordingly, a slurry incubation experiment was carried out in which bacterial and archaeal communities were detected by MiSeq amplicon sequencing. The original microbial community balance was gradually disrupted and new microbial structure was reconstructed subsequently through self-regulation and acclimation during PCP transformation, coupling with the changes of soil biogeochemical redox dynamics...
April 18, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28328216/natural-attenuation-in-streambed-sediment-receiving-chlorinated-solvents-from-underlying-fracture-networks
#17
Burcu Şimşir, Jun Yan, Jeongdae Im, Duane Graves, Frank E Löffler
Contaminant discharge from fractured bedrock formations remains a remediation challenge. We applied an integrated approach to assess the natural attenuation potential of sediment that forms the transition zone between upwelling groundwater from a chlorinated solvent-contaminated fractured bedrock aquifer and the receiving surface water. In situ measurements demonstrated that reductive dechlorination in the sediment attenuated chlorinated compounds before reaching the water column. Microcosms established with creek sediment or in situ incubated Bio-Sep beads degraded C1-C3 chlorinated solvents to less-chlorinated or innocuous products...
May 2, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28273571/detoxification-of-1-1-2-trichloroethane-to-ethene-in-a-bioreactor-co-culture-of-dehalogenimonas-and-dehalococcoides-mccartyi-strains
#18
Siti Hatijah Mortan, Lucía Martín-González, Teresa Vicent, Gloria Caminal, Ivonne Nijenhuis, Lorenz Adrian, Ernest Marco-Urrea
1,1,2-Trichloroethane (1,1,2-TCA) is a non-flammable organic solvent and common environmental contaminant in groundwater. Organohalide-respiring bacteria are key microorganisms to remediate 1,1,2-TCA because they can gain metabolic energy during its dechlorination under anaerobic conditions. However, all current isolates produce hazardous end products such as vinyl chloride, monochloroethane or 1,2-dichloroethane that accumulate in the medium. Here, we constructed a syntrophic co-culture of Dehalogenimonas and Dehalococcoides mccartyi strains to achieve complete detoxification of 1,1,2-TCA to ethene...
February 27, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28238079/development-and-application-of-a-rapid-user-friendly-and-inexpensive-method-to-detect-dehalococcoides-sp-reductive-dehalogenase-genes-from-groundwater
#19
Yogendra H Kanitkar, Robert D Stedtfeld, Paul B Hatzinger, Syed A Hashsham, Alison M Cupples
TaqMan probe-based quantitative polymerase chain reaction (qPCR) specific to the biomarker reductive dehalogenase (RDase) genes is a widely accepted molecular biological tool (MBT) for determining the abundance of Dehalococcoides sp. in groundwater samples from chlorinated solvent-contaminated sites. However, there are significant costs associated with this MBT. In this study, we describe an approach that requires only low-cost laboratory equipment (a bench top centrifuge and a water bath) and requires less time and resources compared to qPCR...
February 25, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28213734/dehalococcoides-and-general-bacterial-ecology-of-differentially-trichloroethene-dechlorinating-flow-through-columns
#20
Babur S Mirza, Darwin L Sorensen, Daniel J McGlinn, R Ryan Dupont, Joan E McLean
The diversity of Dehalococcoides mccartyi (Dhc) and/or other organohalide respiring or associated microorganisms in parallel, partial, or complete trichloroethene (TCE) dehalogenating systems has not been well described. The composition of Dhc populations and the associated bacterial community that developed over 7.5 years in the top layer (0-10 cm) of eight TCE-fed columns were examined using pyrosequencing. Columns biostimulated with one of three carbon sources, along with non-stimulated controls, developed into complete (ethene production, whey amended), partial (cis-dichloroethene (DCE) and VC, an emulsified oil with nonionic surfactant), limited (<5 % cis-DCE and 95 % TCE, an emulsified oil), and non- (controls) TCE dehalogenating systems...
February 17, 2017: Applied Microbiology and Biotechnology
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