Download or read book Characterization of a Dehalococcoides containing Tetrachloroethene Dechlorinating Enrichment Culture written by Brendan Joseph Lazar and published by . This book was released on 2006 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dehalococcoides Ethenogenes Strain 195 written by Xavier Maymó-Gatell and published by . This book was released on 1997 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tetrachioroethene (PCE) is a human carcinogen, and together with trichloroethane (TCE), is widely used. Due to improper handling, they are among the most frequently found groundwater pollutants. A purified, PCE-dechlorinating enrichment culture was developed. This non-methanogenic, non-acetogenic culture could grow with H2 as the electron donor, indicating that H2/PCE serves as an electron donor/acceptor for energy conservation and growth. A novel anaerobic bacterium which dechlorinates PCE to the non-toxic product ethene (ETH), "Dehalococcoides ethenogenes' strain 195, was isolated from this enrichment. This is the first pure culture capable of complete PCE dechlorination. 'D. ethenogenes' strain 195 is an irregular coccus with an optimal growth temperature of 35 deg C and pH of 6.8-7.5. Phylogenetic analysis indicates that it is a eubacterium which shows no affiliation to known groups. Electron donors tested other than H2 were not utilized nor were electron donors other than TCE, cis-dichloroethene (cis-DCE), 1,1-DCE, and dichloroethane, which could be freely interchanged and were dechlorinated to ETH. This organism could not grow on vinyl chloride or trans-DCE when provided as sole electron acceptors, but both were dechlorinated cometabolically by cells previously grown on PCE. The reduction of VC to ETH was the rate-limiting reaction to the complete dechlorination of PCE. PCE, TCE, cis-DCE, and 1,1-DCE inhibited ETH formation from VC when present, but, at low concentrations, their dechlorination coexisted with ETH production. Cultures grown on cis-DCE as sole electron acceptor could not dechlorinate PCE unless PCE and cis-DCE were added together.

Download or read book Development and Characterization of a Rapid Dechlorinating Enrichment Stimulated from an Aquifer Contaminated with Chlorinated Ethenes and Ethanes written by Haekyung Kim and published by . This book was released on 2004 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Metagenome Based Examination of Dechlorinating Enrichment Cultures written by Laura Audrey Hug and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular and Stable Isotope Analysis of Dehalococcoides Bacteria in Chlorinated Ethene Degrading Communities written by Patrick Kwan Hon Lee and published by . This book was released on 2007 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Organohalide Respiring Bacteria written by Lorenz Adrian and published by Springer. This book was released on 2016-08-03 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the current state of knowledge concerning bacteria that use halogenated organic compounds as respiratory electron acceptors. The discovery of organohalide-respiring bacteria has expanded the range of electron acceptors used for energy conservation, and serves as a prime example of how scientific discoveries are enabling innovative engineering solutions that have transformed remediation practice. Individual chapters provide in-depth background information on the discovery, isolation, phylogeny, biochemistry, genomic features, and ecology of individual organohalide-respiring genera, including Dehalococcoides, Dehalogenimonas, Dehalobacter, Desulfitobacterium and Sulfurospirillum, as well as organohalide-respiring members of the Deltaproteobacteria. The book introduces readers to the fascinating biology of organohalide-respiring bacteria, offering a valuable resource for students, engineers and practitioners alike.

Download or read book Novel Insights into Algal Biology and Biotechnology written by Yuval Kaye and published by Frontiers Media SA. This book was released on 2019-05-23 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of a Trichloroethene dechlorinating Mixed Culture written by Minho Lee and published by . This book was released on 2001 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecology of Organohalide respiring Dehalococcoides Mccarty written by Burcu Şimşir and published by . This book was released on 2016 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organohalides such as tetrachloroethene (PCE) and trichloroethene (TCE) are among the most prevalent toxic groundwater contaminants. Remediation of organohalide-contaminated sites has high priority, and efficient and cost-effective remedies are needed to prevent environment and human exposure through contaminated water. Bacterial organohalide-respiration plays a major role in organohalide detoxification. Dehalococcoides mccartyi (Dhc) are key mediators in bioremediation, since only Dhc strains have been documented in complete detoxification of chlorinated ethenes to benign ethene. Dhc depends on other microorganisms in the environment for essential growth requirements (e.g., hydrogen and vitamins). For successful implementation of the reductive dechlorination to remediate contaminated sites, microbial interactions controlling Dhc reductive dechlorination must be elucidated. The overall objective of this research was to address the key gaps in the scientific understanding of the controls over Dhc reductive dechlorination activity, including Dhc corrinoid-related interactions with other microorganisms. Detailed hydrogeological and microbial characterization of mixed chlorinated solvent contaminated Third Creek site (Knoxville, TN) attributed an important role to the creek sediment, where organohalide-respiring bacteria (e.g., Dhc and Dehalobacter) co-exist, for detoxification of contaminants. Different chlorinated solvent-amendments affected Dhc strain selection and non-dechlorinating microbial composition in enrichment cultures derived from Third Creek sediment. Corrinoid-auxotroph Dhc require corrinoid cofactor for the reductive dehalogenase enzyme systems. Microorganisms including Acetobacterium, Clostridium, Geobacter, and methanogens were identified as corrinoid-producers in the enrichment cultures. 5,6- dimethyl-benzimidazole cobamide (DMB-Cba) was the most abundant corrinoid in enrichment cultures to support Dhc reductive dechlorination. Different lower base-amendments affected Dhc reductive dechlorination rates and extents. Lower base-amendments to enrichment cultures caused a shift from production of DMB-Cba to production of corrinoids with the amended lower bases, some of which caused lower dechlorination rates. In addition, different Dhc strains became abundant with different lower base-amendment in cultures, demonstrating the role of corrinoid in Dhc strain selection. Lastly this research demonstrated that different geochemical conditions and corresponding microbial populations determined the composition and concentration of bioavailable corrinoid pools; thus directly controlling Dhc reductive dechlorination activity. The findings of this research are relevant to environmental remediation practitioners and provide valuable information for improving bioremediation strategies to achieve successful contaminated-site cleanup.

Download or read book Characterization of Tetrachloroethene Dechlorinating Cultures and Isolation of a Novel Tetrachloroethene to Cis 1 2 dichloroethene Halorespiring Bacterium written by Jaana M. H. Pietari and published by . This book was released on 2002 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Reductive Dehalogenases in a Chlorinated Ethene Degrading Bioaugmentation Culture written by Winnie Wing Man Chan and published by . This book was released on 2010 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perchloroethene and trichloroethene are among the most persistent groundwater pollutants, and Dehalococcoides is the only known species that can degrade these compounds completely to non-toxic ethene. Characterization of the reductive dehalogenase (RDase) enzymes responsible for dechlorination is important to understanding this process. A series of dechlorination assays were performed with whole cell suspensions and cell-free extracts of three Dehalococcoides-containing mixed microbial consortia to compare dechlorination kinetics and to characterize co-contaminant inhibition. Michaelis-Menten kinetic parameters Vmax and Km, as well as non-competitive inhibition coefficients for 1,1,1-trichloroethane and 1,1-dichloroethane inhibitors are reported. Secondly, blue native gel electrophoresis was developed as a method to isolate active protein complexes containing RDases. Thirdly, sources of variability in the isotopic fractionation of vinyl chloride to ethene reaction step were examined using cell-free extracts and whole-cell suspensions. Understanding the function and range of RDases are goals towards the successful application of Dehalococcoides-containing cultures to remediate contaminated sites.

Download or read book Biodegradation of Hazardous and Special Products written by Rolando Chamy and published by BoD – Books on Demand. This book was released on 2013-06-14 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains a collection of different research activities that include the biodegradation compounds with contaminant characteristics and special products of different interests as an added value product or that allows following up various biological processes. The chapters consider the degradation of contaminant compounds generated by industrial activities, i.e., oil industry by-product compounds and halogen compounds or compound generated by natural phenomena such as tsunamis, which require interventions to recover damaged soils. In addition, the book contains chapters that involve special product degradation processes such as chlorophyll, which corresponds to a biological process indicator as photosynthesis.

Download or read book Bioaugmentation for Groundwater Remediation written by Hans F. Stroo and published by Springer Science & Business Media. This book was released on 2012-10-02 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: ​This volume provides a review of the past 10 to 15 years of intensive research, development and demonstrations that have been on the forefront of developing bioaugmentation into a viable remedial technology. This volume provides both a primer on the basic microbial processes involved in bioaugmentation, as well as a thorough summary of the methodology for implementing the technology. This reference volume will serve as a valuable resource for environmental remediation professionals who seek to understand, evaluate, and implement bioaugmentation.

Download or read book Investigation of Community Dynamics and Dechlorination Processes in Chlorinated Ethane degrading Microbial Cultures written by Ariel Grostern and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this research was to investigate the microorganisms, genetics and biochemistry of anaerobic dechlorination of chlorinated ethanes, which are common groundwater contaminants. Specifically, this project used mixed microbial cultures to study the dechlorination of 1,2-dichloroethane (1,2-DCA), 1,1,2-trichloroethane (1,1,2-TCA) and 1,1,1-trichloroethane (1,1,1-TCA).A mixed microbial culture enriched from a contaminated multilayered aquifer in West Louisiana dechlorinated 1,2-DCA, 1,1,2-TCA, tetrachloroethene, trichloroethene, cis-dichloroethene and vinyl chloride (VC) to non-toxic ethene when amended with ethanol as the electron donor. 16S rRNA gene sequence analysis revealed the presence of the putative dechlorinating organisms Dehalobacter and Dehalococcoides spp. Denaturing gradient gel electrophoresis analysis and quantitative PCR (qPCR) with species-specific primers demonstrated that both organisms grew during the dichloroelimination of 1,2-DCA to ethene. Conversely, during the dichloroelimination of 1,1,2-TCA to VC only Dehalobacter grew, while during the reductive dechlorination of VC to ethene only Dehalococcoides grew. Further enrichment with 1,2-DCA, H2 and acetate yielded a co-culture of Dehalobacter and Acetobacterium spp. that did not dechlorinate other chlorinated ethanes or ethenes. Dehalobacter grew in the presence but not in the absence of 1,2-DCA, while Acetobacterium growth was not affected by 1,2-DCA. A novel putative Dehalobacter -associated 1,2-DCA reductive dehalogenase gene was identified and was shown to be transcribed only in the presence of 1,2-DCA. An enrichment microbial culture derived from a 1,1,1-TCA-contaminated site in the northeastern United States was also studied. This culture, referred to as MS, reductively dechlorinated 1,1,1-TCA to 1,1-dichloroethane (1,1-DCA) and then to monochloroethane (CA) when amended with methanol, ethanol, acetate and lactate. 16S rRNA gene sequence analysis revealed the presence of the putative dechlorinating organism Dehalobacter sp., whose growth during 1,1,1-TCA and 1,1-DCA dechlorination was confirmed by qPCR. In the presence of chlorinated ethenes, dechlorination 1,1,1-TCA by the culture MS was slowed, while dechlorination of 1,1-DCA was completely inhibited. Experiments with cell-free extracts and whole cell suspensions of culture MS suggested that chlorinated ethenes have direct inhibitory effects on 1,1,1-TCA reductive dehalogenase(s), while the inhibition of 1,1-DCA dechlorination may be due to effects on non-dehalogenase components of Dehalobacter sp. cells. Additionally, two novel reductive dehalogenase genes associated with 1,1,1-TCA reductive dechlorination were identified.

Download or read book Community Structure and Dynamics of Anaerobic Chlorinated Ethene degrading Enrichment Cultures microform written by Melanie Annette Duhamel and published by Library and Archives Canada = Bibliothèque et Archives Canada. This book was released on 2005 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this research was to characterize a set of anaerobic chlorinated ethene-degrading cultures referred to as KB-1. PCR-denaturing gradient gel electrophoresis and 16S rRNA gene sequence analysis were used to identify key populations in cultures enriched on each chlorinated ethene. Two Dehalococcoides populations were detected in KB-1. One, designated KB-1/VC, was found in all cultures. The other, designated KB-1/PCE, was absent in highly enriched cultures maintained on vinyl chloride. Novel SYBRRTM Green real-time quantitative PCR methods were developed for thirteen of the populations detected: Acetobacterium, Bacteroides, Dehalococcoides, Geobacter, Spirochaetes, Sporomusa, Sulfurospirillum, Syntrophobacter, Syntrophus, Methanomethylovorans, Methanomicrobiales, Methanosaeta, and Methanosarcina. These quantitative PCR techniques were used on thirty DNA samples from various KB-1 cultures, revealing that Dehalococcoides spp. were the dominant detectable members of most cultures, followed by Sporomusa, Spirochaetes, and Methanomethylovorans populations. A Geobacter population was present only in cultures maintained on perchloroethene and trichloroethene, suggesting that this population degraded perchloroethene to cis-1,2-dichloroethene. This hypothesis was supported by a timecourse experiment during which the Geobacter population grew alongside Dehalococcoides spp. during trichloroethene degradation to cis-1,2-dichloroethene, while complete dechlorination to ethene was associated with Dehalococcoides growth. Dehalococcoides was also associated with dihaloelimination of 1,2-dichlorethane to ethene. The acetogenic Sporomusa population grew on methanol as well as H2/CO 2 and may have converted methanol to H2 for Dehalococcoides spp. Dehalococcoides KB-1/PCE and KB-1/VC had identical 16S rRNA gene sequences to published strains with different substrate ranges. Ribosomal intergenic spacer analysis was unable to resolve differences between Dehalococcoides populations because Dehalococcoides does not have the usual arrangement of rRNA genes. Gyrase B gene sequence analysis using the novel Dehalococcoides-specific primer sets was also unable to distinguish between organisms with identical 16S rRNA gene sequences. Efforts to isolate a Dehalococcoides population capable of rapid growth on vinyl chloride and H2 yielded a nonmethanogenic,>95% pure Dehalococcoides KB-1/VC culture that grew on all dechlorination steps from trichloroethene to ethene. Amending this culture with methanol resulted in higher dechlorination rates, which may have been attributable to the sudden growth of Sporomusa in these cultures.

Download or read book Reductive Dechlorination of High Concenrations of Tetrachloroethylene by Anaerobic Enrichment Culture written by Tao Wang and published by . This book was released on 1997 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Anaerobic Degradation of 1 1 2 2 tetrachloroethane and Association with Microbial Communities in a Freshwater Tidal Wetland Aberdeen Proving Ground Maryland written by Michelle M. Lorah and published by . This book was released on 2003 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: