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Hui Wan, Xiaoyun Yi, Xiaoping Liu, Chunhua Feng, Zhi Dang, Chaohai Wei
Applying an electric field to stimulate the microbial reductive dechlorination of polychlorinated biphenyls (PCBs) represents a promising approach for bioremediation of PCB-contaminated sites. This study aimed to demonstrate the biocathodic film-facilitated reduction of PCB 61 in a sediment-based bioelectrochemical reactor (BER) and, more importantly, the characterizations of electrode-microbe interaction from microbial and electrochemical perspectives particularly in a time-dependent manner. The application of a cathodic potential (-0...
May 2018: Environmental Pollution
Holly L Sewell, Anne-Kristin Kaster, Alfred M Spormann
The deep marine subsurface is one of the largest unexplored biospheres on Earth and is widely inhabited by members of the phylum Chloroflexi In this report, we investigated genomes of single cells obtained from deep-sea sediments of the Peruvian Margin, which are enriched in such Chloroflexi 16S rRNA gene sequence analysis placed two of these single-cell-derived genomes (DscP3 and Dsc4) in a clade of subphylum I Chloroflexi which were previously recovered from deep-sea sediment in the Okinawa Trough and a third (DscP2-2) as a member of the previously reported DscP2 population from Peruvian Margin site 1230...
December 19, 2017: MBio
Jan Němeček, Jana Steinová, Roman Špánek, Tomáš Pluhař, Petr Pokorný, Petra Najmanová, Vladislav Knytl, Miroslav Černík
In situ bioremediation (ISB) using reductive dechlorination is a widely accepted but relatively slow approach compared to other technologies for the treatment of groundwater contaminated by chlorinated ethenes (CVOCs). Due to the known positive kinetic effect on microbial metabolism, thermal enhancement may be a viable means of accelerating ISB. We tested thermally enhanced ISB in aquifers situated in sandy saprolite and underlying fractured granite. The system comprised pumping, heating and subsequent injection of contaminated groundwater aiming at an aquifer temperature of 20-30°C...
May 1, 2018: Science of the Total Environment
Jacob E Munro, Önder Kimyon, Deborah J Rich, Joanna Koenig, Sihui Tang, Adrian Low, Matthew Lee, Mike Manefield, Nicholas V Coleman
1,2-Dichloroethane (DCA) is a problematic groundwater pollutant. Factors influencing the distribution and activities of DCA-degrading bacteria are not well understood, which has hampered their application for bioremediation. Here, we used quantitative PCR to investigate the distribution of putative DCA-dehalogenating bacteria at a DCA-impacted site in Sydney (Australia). The dehalogenase genes dhlA, tceA and bvcA were detected in all groundwater samples (n = 15), while vcrA was found in 11/15 samples. The 16S rRNA gene sequences specific to the dehalogenating genera Dehalobacter, Desulfitobacterium and Dehalogenimonas were detected in 15/15, 13/15 and 13/15 samples, respectively, while Dehalococcoides sequences were found in 9/15 samples...
November 1, 2017: FEMS Microbiology Ecology
Juan Chen, Pei-Fang Wang, Chao Wang, Jia-Jia Liu, Han Gao, Xun Wang
It is acknowledged that organohalide-respiring bacteria (OHRB) can degrade polybrominated diphenyl ethers (PBDEs); however, very little is known about the distribution of OHRB or their response to PBDE contamination in natural sediments. We collected sediments from 28 sampling sites in Taihu Lake, China, and investigated the spatial distribution and diversity of OHRB, and the relationships between the PBDE contamination levels and the PBDE removal potential. The abundances of five typical OHRB genera, namely Dehalobacter, Dehalococcoides, Dehalogenimonas, Desulfitobacterium, and Geobacter, ranged from 0...
January 2018: Environmental Pollution
Simon Leitner, Harald Berger, Markus Gorfer, Thomas G Reichenauer, Andrea Watzinger
Reductive dechlorination performed by organohalide-respiring bacteria (OHRB) enables the complete detoxification of certain emerging groundwater pollutants such as perchloroethene (PCE). Environmental samples from a contaminated site incubated in a lab-scale microcosm (MC) study enable documentation of such reductive dechlorination processes. As compound-specific isotope analysis is used to monitor PCE degradation processes, nucleic acid analysis-like 16S-rDNA analysis-can be used to determine the key OHRB that are present...
November 2017: Environmental Science and Pollution Research International
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...
December 2017: ISME Journal
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...
January 5, 2018: Journal of Hazardous Materials
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...
June 5, 2017: Journal of Hazardous Materials
J Palau, R Yu, S Hatijah Mortan, O Shouakar-Stash, M Rosell, D L Freedman, C Sbarbati, S Fiorenza, R Aravena, E Marco-Urrea, M Elsner, A Soler, D Hunkeler
This study investigates, for the first time, dual C-Cl isotope fractionation during anaerobic biodegradation of 1,2-dichloroethane (1,2-DCA) via dihaloelimination by Dehalococcoides and Dehalogenimonas-containing enrichment cultures. Isotopic fractionation of 1,2-DCA (εbulk(C) and εbulk(Cl)) for Dehalococcoides (-33.0 ± 0.4‰ and -5.1 ± 0.1‰) and Dehalogenimonas-containing microcosms (-23 ± 2‰ and -12.0 ± 0.8‰) resulted in distinctly different dual element C-Cl isotope correlations (Λ = Δδ(13)C/Δδ(37)Cl ≈ εbulk(C)/εbulk(Cl)), 6...
March 7, 2017: Environmental Science & Technology
Trent A Key, Kimberly S Bowman, Imchang Lee, Jongsik Chun, Luciana Albuquerque, Milton S da Costa, Fred A Rainey, William M Moe
A strictly anaerobic, Gram-stain-negative, non-spore-forming bacterium designated NSZ-14T, isolated from contaminated groundwater in Louisiana (USA), was characterized using a polyphasic approach. Strain NSZ-14T reductively dehalogenated a variety of polychlorinated aliphatic alkanes, producing ethene from 1,2-dichloroethane, propene from 1,2-dichloropropane, a mixture of cis- and trans-1,2-dichloroethene from 1,1,2,2-tetrachloroethane, vinyl chloride from 1,1,2-trichloroethane and allyl chloride (3-chloro-1-propene) from 1,2,3-trichloropropane...
May 2017: International Journal of Systematic and Evolutionary Microbiology
Hui Yu, Hui Wan, Chunhua Feng, Xiaoyun Yi, Xiaoping Liu, Yuan Ren, Chaohai Wei
The necessity for developing an efficient and cost-effective in situ bioremediation technology for sediments contaminated with polychlorinated biphenyls (PCBs) has prompted the application of low-voltage electrical fields to anaerobic digestion systems. Here we show that the use of a sediment-based bio-electrochemical reactor (BER) poised at a potential of -0.50V (vs. a standard calomel electrode, SCE) substantially enhanced the reduction of 2,3,4,5-tetrachlorobiphenyl (PCB 61) when acetate was added as a carbon source...
February 15, 2017: Science of the Total Environment
Trent A Key, Dray P Richmond, Kimberly S Bowman, Yong-Joon Cho, Jongsik Chun, Milton S da Costa, Fred A Rainey, William M Moe
Dehalogenimonas alkenigignens IP3-3(T) is a strictly anaerobic, mesophilic, Gram negative staining bacterium that grows by organohalide respiration, coupling the oxidation of H2 to the reductive dehalogenation of polychlorinated alkanes. Growth has not been observed with any non-polyhalogenated alkane electron acceptors. Here we describe the features of strain IP3-3(T) together with genome sequence information and its annotation. The 1,849,792 bp high-quality-draft genome contains 1936 predicted protein coding genes, 47 tRNA genes, a single large subunit rRNA (23S-5S) locus, and a single, orphan, small unit rRNA (16S) locus...
2016: Standards in Genomic Sciences
Chris M D Kocur, Line Lomheim, Olivia Molenda, Kela P Weber, Leanne M Austrins, Brent E Sleep, Hardiljeet K Boparai, Elizabeth A Edwards, Denis M O'Carroll
Nanoscale zerovalent iron (nZVI) is an emerging technology for the remediation of contaminated sites. However, there are concerns related to the impact of nZVI on in situ microbial communities. In this study, the microbial community composition at a contaminated site was monitored over two years following the injection of nZVI stabilized with carboxymethyl cellulose (nZVI-CMC). Enhanced dechlorination of chlorinated ethenes to nontoxic ethene was observed long after the expected nZVI oxidation. The abundance of Dehalococcoides (Dhc) and vinyl chloride reductase (vcrA) genes, monitored using qPCR, increased by over an order of magnitude in nZVI-CMC-impacted wells...
July 19, 2016: Environmental Science & Technology
Ivonne Nijenhuis, Kevin Kuntze
Contamination and remediation of groundwater with halogenated organics and understanding of involved microbial reactions still poses a challenge. Over the last years, research in anaerobic microbial dehalogenation has advanced in many aspects providing information about the reaction, physiology of microorganisms as well as approaches to investigate the activity of microorganisms in situ. Recently published crystal structures of reductive dehalogenases (Rdh), heterologous expression systems and advanced analytical, proteomic and stable isotope approaches allow addressing the overall reaction and specific enzymes as well as co-factors involved during anaerobic microbial dehalogenation...
April 2016: Current Opinion in Biotechnology
Chih-Ming Kao, Hung-Yu Liao, Chih-Ching Chien, Yi-Kuan Tseng, Petrus Tang, Chih-En Lin, Ssu-Ching Chen
The compositions of bacterial community in one site contaminated with PCE/TCE after the slow polycolloid-releasing substrate (SPRS) (contained vegetable oil, cane molasses, and surfactants) addition were analyzed. Results show that SPRS caused a rapid enhancement of reductive dechlorination of TCE. The transformation of PCE/TCE into ethene was observed after 20 days of operation. To compare the change of bacterial communities before and after SPRS addition, 16S rRNA amplicon sequencing using the metagenome analysis was performed...
January 25, 2016: Journal of Hazardous Materials
Olivia Molenda, Andrew T Quaile, Elizabeth A Edwards
The Dehalogenimonas population in a dechlorinating enrichment culture referred to as WBC-2 was previously shown to be responsible for trans-dichloroethene (tDCE) hydrogenolysis to vinyl chloride (VC). In this study, blue native polyacrylamide gel electrophoresis (BN-PAGE) followed by enzymatic assays and protein identification using liquid chromatography coupled with mass spectrometry (LC-MS/MS) led to the functional characterization of a novel dehalogenase, TdrA. This new reductive dehalogenase (RDase) catalyzes the dechlorination of tDCE to VC...
January 1, 2016: Applied and Environmental Microbiology
L Martín-González, S Hatijah Mortan, M Rosell, E Parladé, M Martínez-Alonso, N Gaju, G Caminal, L Adrian, E Marco-Urrea
A stable enrichment culture derived from Besòs river estuary sediments stoichiometrically dechlorinated 1,2-dichloropropane (1,2-DCP) to propene. Sequential transfers in defined anaerobic medium with the inhibitor bromoethanesulfonate produced a sediment-free culture dechlorinating 1,2-DCP in the absence of methanogenesis. Application of previously published genus-specific primers targeting 16S rRNA gene sequences revealed the presence of a Dehalogenimonas strain, and no amplification was obtained with Dehalococcoides-specific primers...
July 21, 2015: Environmental Science & Technology
Jie Chen, Kimberly S Bowman, Fred A Rainey, William M Moe
Representatives from the genus Dehalogenimonas have the metabolic capacity to anaerobically transform a variety of environmentally important polychlorinated aliphatic compounds. In light of the recent isolation of additional strains, description of a new species, and an expanded number of uncultured DNA sequences, PCR primers and protocols intended to uniquely target members of this organohalide-respiring genus were reevaluated. Nine of fourteen primer combinations reported previously as genus-specific failed to amplify 16S rRNA genes of recently isolated Dehalogenimonas strains...
September 2014: Biodegradation
Dasha A Ravinesan, Radhey S Gupta
The bacteria belonging to the class Dehalococcoidia, due to their ability to dehalogenate chlorinated compounds, are of much interest for bioremediation of contaminated sites. We report here comparative analyses on different genes/proteins from the genomes of members of the class Dehalococcoidia. These studies have identified numerous novel molecular markers in the forms of conserved signature indels (CSIs) in broadly distributed proteins and conserved signature genes/proteins (CSPs), which are uniquely found in members of the class Dehalococcoidia, but except for an isolated exception, they are not found in other sequenced bacterial genomes...
June 2014: International Journal of Systematic and Evolutionary Microbiology
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