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Xinwei Mao, Ronald S Oremland, Tong Liu, Sara Gushgari, Abigail A Landers, Shaun M Baesman, Lisa Alvarez-Cohen
Acetylene (C2 H2 ) can be generated in contaminated groundwater sites as a consequence of chemical degradation of trichloroethene (TCE) by in situ minerals, and C2 H2 is known to inhibit bacterial dechlorination. In this study, we show that while high C2 H2 (1.3 mM) concentrations reversibly inhibit reductive dechlorination of TCE by Dehalococcoides mccartyi isolates as well as enrichment cultures containing D. mccartyi sp., low C2 H2 (0.4 mM) concentrations do not inhibit growth or metabolism of D. mccartyi...
February 21, 2017: Environmental Science & Technology
Bryan Jk Smith, Melissa A Boothe, Brice A Fiddler, Tania M Lozano, Russel K Rahi, Mark J Krzmarzick
Organohalide contaminants such as triclosan and triclocarban have been well documented in municipal wastewater treatment plants (WWTPs), but the degradation of these contaminants is not well understood. One possible removal mechanism is organohalide respiration by which bacteria reduce the halogenated compound. The purpose of this study was to determine the abundance of organohalide-respiring bacteria in eight WWTP anaerobic digesters. The obligate organohalide respiring Dehalococcoides mccartyi was the most abundant and averaged 3...
2015: Microbiology Insights
Tobias Goris, Christian L Schiffmann, Jennifer Gadkari, Torsten Schubert, Jana Seifert, Nico Jehmlich, Martin von Bergen, Gabriele Diekert
Organohalide respiration is an environmentally important but poorly characterized type of anaerobic respiration. We compared the global proteome of the versatile organohalide-respiring Epsilonproteobacterium Sulfurospirillum multivorans grown with different electron acceptors (fumarate, nitrate, or tetrachloroethene [PCE]). The most significant differences in protein abundance were found for gene products of the organohalide respiration region. This genomic region encodes the corrinoid and FeS cluster containing PCE reductive dehalogenase PceA and other proteins putatively involved in PCE metabolism such as those involved in corrinoid biosynthesis...
September 21, 2015: Scientific Reports
Xiaoming Liang, Olivia Molenda, Shuiquan Tang, Elizabeth A Edwards
Many reductive dehalogenases (RDases) have been identified in organohalide-respiring microorganisms, and yet their substrates, specific activities, and conditions for expression are not well understood. We tested whether RDase expression varied depending on the substrate-exposure history of reductive dechlorinating communities. For this purpose, we used the enrichment culture KB-1 maintained on trichloroethene (TCE), as well as subcultures maintained on the intermediates cis-dichloroethene (cDCE) and vinyl chloride (VC)...
July 2015: Applied and Environmental Microbiology
Tobias Goris, Bastian Hornung, Thomas Kruse, Anika Reinhold, Martin Westermann, Peter J Schaap, Hauke Smidt, Gabriele Diekert
This genome report describes the draft genome and the physiological characteristics of Desulfitobacterium hafniense PCE-S, a Gram-positive bacterium known to dechlorinate tetrachloroethene (PCE) to dichloroethene by a PCE reductive dehalogenase. The draft genome has a size of 5,666,696 bp with a G + C content of 47.3%. The genome is very similar to the already sequenced Desulfitobacterium hafniense Y51 and the type strain DCB-2. We identified two complete reductive dehalogenase (rdh) genes in the genome of D...
2015: Standards in Genomic Sciences
Eric M Adetutu, Taylor D Gundry, Sayali S Patil, Aida Golneshin, Joy Adigun, Vijay Bhaskarla, Samuel Aleer, Esmaeil Shahsavari, Elizabeth Ross, Andrew S Ball
Bioremediation of trichloroethene (TCE) polluted groundwater is challenging, with limited next generation sequencing (NGS) derived information available on microbial community dynamics associated with dechlorination. Understanding these dynamics is important for designing and improving TCE bioremediation. In this study, biostimulation (BS), biostimulation-bioaugmentation (BS-BA) and monitored natural attenuation (MNA) approaches were applied to contaminated groundwater wells resulted in ≥ 95% dechlorination within 7 months...
December 30, 2015: Journal of Hazardous Materials
Chao Yang, Anja Kublik, Cindy Weidauer, Bettina Seiwert, Lorenz Adrian
Dehalococcoides mccartyi strains transform many halogenated compounds and are used for bioremediation. Such anaerobic transformations were intensively studied with chlorinated and simply structured compounds such as chlorinated benzenes, ethenes, and ethanes. However, many halogenated oligocyclic aromatic compounds occur in nature as either naturally produced materials or as part of commercial products such as pharmaceuticals, pesticides, or flame retardants. Here, we demonstrate that the D. mccartyi strain CBDB1 reductively debrominated two oligocyclic aromatic phenolic compounds, tetrabromobisphenol A (TBBPA) and bromophenol blue (BPB)...
July 21, 2015: Environmental Science & Technology
Huixin Zhang, Ania C Ulrich, Yang Liu
The influence of solution chemistry on microbial transport was examined using the strictly anaerobic trichloroethene (TCE) bioaugmentation culture KB-1(®). A column was employed to determine transport behaviors and deposition kinetics of three distinct functional species in KB-1(®), Dehalococcoides, Geobacter, and Methanomethylovorans, over a range of ionic strengths under a well-controlled anaerobic condition. A quantitative polymerase chain reaction (qPCR) was utilized to enumerate cell concentration and complementary techniques were implemented to evaluate cell surface electrokinetic potentials...
June 1, 2015: Colloids and Surfaces. B, Biointerfaces
R Satpathy, V B Konkimalla, J Ratha
Microbial dehalogenation is a biochemical process in which the halogenated substances are catalyzed enzymatically in to their non-halogenated form. The microorganisms have a wide range of organohalogen degradation ability both explicit and non-specific in nature. Most of these halogenated organic compounds being pollutants need to be remediated; therefore, the current approaches are to explore the potential of microbes at a molecular level for effective biodegradation of these substances. Several microorganisms with dehalogenation activity have been identified and characterized...
January 2015: Prikladnaia Biokhimiia i Mikrobiologiia
Julian Renpenning, Insa Rapp, Ivonne Nijenhuis
This study investigated the effect of intracellular microscale mass transfer on microbial carbon isotope fractionation of tetrachloroethene (PCE) and trichloroethene (TCE). Significantly stronger isotope fractionation was observed for crude extracts vs intact cells of Sulfurospirillum multivorans, Geobacter lovleyi, Desulfuromonas michiganensis, Desulfitobacterium hafniense strain PCE-S, and Dehalobacter restrictus. Furthermore, carbon stable isotope fractionation was stronger for microorganisms with a Gram-positive cell envelope compared to those with a Gram-negative cell envelope...
April 7, 2015: Environmental Science & Technology
Yan Xu, Yan He, Qian Zhang, Jianming Xu, David Crowley
Carbon isotopic analysis and molecular-based methods were used in conjunction with geochemical data sets to assess the dechlorination of pentachlorophenol (PCP) when coupled to biogeochemical processes in a mangrove soil having no prior history of anthropogenic contamination. The PCP underwent 96% dechlorination in soil amended with acetate, compared to 21% dehalogenation in control soil. Carbon isotope analysis of residual PCP demonstrated an obvious enrichment of 13C (εC, -3.01±0.1%). Molecular and statistical analyses demonstrated that PCP dechlorination and Fe(III) reduction were synergistically combined electron-accepting processes...
May 5, 2015: Environmental Science & Technology
Anutthaman Parthasarathy, Troy A Stich, Svenja T Lohner, Ann Lesnefsky, R David Britt, Alfred M Spormann
Reductive dehalogenases play a critical role in the microbial detoxification of aquifers contaminated with chloroethenes and chlorethanes by catalyzing the reductive elimination of a halogen. We report here the first heterologous production of vinyl chloride reductase VcrA from Dehalococcoides mccartyi strain VS. Heterologously expressed VcrA was reconstituted to its active form by addition of hydroxocobalamin/adenosylcobalamin, Fe(3+), and sulfide in the presence of mercaptoethanol. The kinetic properties of reconstituted VcrA catalyzing vinyl chloride reduction with Ti(III)-citrate as reductant and methyl viologen as mediator were similar to those obtained previously for VcrA as isolated from D...
March 18, 2015: Journal of the American Chemical Society
Siyan Zhao, Chang Ding, Jianzhong He
1,1,2-trichloroethane (1,1,2-TCA) has become a common groundwater pollutant due to historically extensive utilization, improper disposal, as well as from incomplete dechlorination of 1,1,2,2-tetrachloroethane. Currently, limited information is available on microbial detoxification of 1,1,2-TCA. Desulfitobacterium sp. strain PR, which was isolated from an anaerobic bioreactor maintained to dechlorinate chloroethenes/ethanes, exhibited the capacity to dechlorinate 1,1,1-trichloroethane and chloroform. In this study, the dechlorinating ability of strain PR was further explored...
2015: PloS One
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