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 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 Biokinetic Modeling Laboratory Examination and Field Analysis of DNA RNA and Protein as Robust Molecular Biomarkers of Chloroethene Reductive Dechlorination in Dehalococcoides Mccartyi written by Gretchen Lee Watson Heavner and published by . This book was released on 2013 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: DNA, RNA and protein were tested as specific and robust biomarkers of anaerobic reductive dechlorination by Dehalococcoides (DMC) species in predictive modeling, with mixed microbial cultures and at a field site. A comprehensive biokinetic model of a community containing DMC strain 195 was updated to describe continuously fed reactors with specific biomass levels based on quantitative PCR (qPCR)-based population data (DNA and RNA). The model was calibrated and validated with subsets of chemical and molecular biological data from various continuous feed experiments (n=24) with different loading rates of the electron acceptor (1.5 to 482 [MICRO SIGN]eeq/L-h), types of electron acceptor (PCE, TCE, cis-DCE) and electron donor to electron acceptor ratios. Based on early model results, both competitive inhibition of chloroethene degradation and empirically derived mRNA "adjustment factors" were added to the model. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) data were taken from microcosms containing the KB-1TM consortium (SiREM Labs of Guelph, Ontario, Canada), operated under continuous, chlorinated ethene feed conditions, with the aim of clarifying relationships and creating more robust set of biomarkers that could be used at field sites bioaugmented with the KB-1TM culture. The correlation between respiration rate and mRNA transcript number was upheld for the hydrogenase HupL, and significant differences were observed for reductive dehalogenases (RDases) TceA and DET1545 when comparing the two mixed cultures studied (KB-1TM and D2). A correlation was also observed for RDase VcrA expression compared to respiration rate in the KB-1TM mixed culture. Additionally, correlation trends for HupL and VcrA were upheld when looking at proteomic ion intensities as compared to respiration rates, though protein changes were not as drastic as they were for mRNA transcripts. Additional experiments were conducted to quantify these biomarkers under stress conditions (presence of oxygen or low pH). Addition of stressors caused respiration rates to decrease significantly, whereas transcript abundances exhibited a slow decay (0.02-0.03 per hr) over the time period studied, indicating that transcript abundance alone cannot predict respiration rate in stressed conditions within hours to days following stress. A successful proteomics-based method was developed for identifying DMC and Geobacter biomarkers of reductive dechlorination at a trichloroethene-contaminated industrial site in Ft. Erie, Ontario that had been bio-augmented with the commercially-available KB-1TM microbial culture two years prior. Samples were obtained from two wells with high hydraulic connectivity to the enhanced in-situ bioremediation system, and two with low hydraulic connectivity. The DNA and RNA biomarkers detected were a set of reductive dehalogenases, and the highly-conserved hydrogenase, HupL. Proteomic biomarkers of organohalide respiration were detected in all four field samples' metaproteomes, and the key reductive dehalogenases present in the bioaugmentation culture were the most highly detected proteins overall, suggesting that deployed DMC strains maintain devotion to high RDase concentrations in the field.

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 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 Smart Bioremediation Technologies written by Pankaj Bhatt and published by Academic Press. This book was released on 2019-06-07 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: Smart Bioremediation Technologies: Microbial Enzymes provides insights into the complex behavior of enzymes and identifies metabolites and their degradation pathways. It will help readers work towards solutions for sustainable medicine and environmental pollution. The book highlights the microbial enzymes that have replaced many plant and animal enzymes, also presenting their applications in varying industries, including pharmaceuticals, genetic engineering, biofuels, diagnostics and therapy. In addition, new methods, including genomics and?metagenomics, are being employed for the discovery of new enzymes from microbes. This book brings all of these topics together, representing the first resource on how to solve problems in bioremediation. Provides the most novel approaches in enzyme studies Gives insights in real-time enzymology that are correlated with bioremediation Serves as a valuable resource on the use of genomes, transcriptomes and proteomes with bioremediation Refers to enzymes as diagnostic tools

Download or read book Bioremediation of Chlorinated Ethenes written by Yi Yang and published by . This book was released on 2016 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chlorinated solvents have been widely used in different areas of modern society. Usage of these chlorinated solvents was not necessarily accompanied with proper handling and disposal of these hazardous compounds, which caused a variety of environmental problems and continues to affect human health. Remediation of chlorinated ethenes contaminated sites has high priority for state regulators and site owners. Among the available treatment technologies, bioremediation shows great promise as a cost-effective corrective strategy for a variety of environmental pollutants. Prerequisites are that the microbiology involved in contaminant degradation and geochemical factors, such as pH, are understood, so that bioremediation technologies can be confidently implemented. The aims of this dissertation work were 1) to enrich and isolate PCE dechlorinators under low pH conditions, 2) to investigate how pH fluctuations affect the microbial community of a PCE-to-ethene consortium, 3) to determine the pH tolerance of Dehalococcoides mccartyi (Dhc), 4) to identify a non-Dehalococcoides type microorganism responsible for reductive dechlorination of vinyl chloride, 5) to identify and characterize a novel vinyl chloride reductase gene and 6) to develop an Excel-based tool to guide remedial practitioners to select suitable remediation strategies. Only one enrichment culture out of total sixteen sites samples showed PCE dechlorination activity at pH 5.5 and stoichiometric conversion to cDCE occurred after repeated transfers. The analysis of 16S rRNA gene sequencing data revealed the genera Desulfovibrio, Sulfurospirillum, and Megasphaera were most abundant in pH 5.5 enrichment. Two PCE-dechlorinating isolates (strains PLC-TCE and PLC-DCE) were obtained from a pH 5.5 enrichment, and identified as members of the genus Sulfurospirillum. Experiments with a Dhc-containing consortium demonstrated that exposure time affected Dhc ability to recover reductive dechlorination activity following low pH exposure. Low pH conditions affected Dhc strains differently, and Dhc strains carrying the vcrA gene responsible for reductive dechlorination of the human carcinogen vinyl chloride (VC) were least tolerant to low pH. Enrichment and isolation efforts led to the discovery of a Dehalogenimonas (Dhgm) species capable of respiring chlorinated ethenes, including VC. These research findings advance understanding of the microbial reductive dechlorination process and will improve the implementation of in situ bioremediation.

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 Comprehensive Biotechnology written by and published by Elsevier. This book was released on 2019-07-17 with total page 4876 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Biotechnology, Third Edition, Six Volume Set unifies, in a single source, a huge amount of information in this growing field. The book covers scientific fundamentals, along with engineering considerations and applications in industry, agriculture, medicine, the environment and socio-economics, including the related government regulatory overviews. This new edition builds on the solid basis provided by previous editions, incorporating all recent advances in the field since the second edition was published in 2011. Offers researchers a one-stop shop for information on the subject of biotechnology Provides in-depth treatment of relevant topics from recognized authorities, including the contributions of a Nobel laureate Presents the perspective of researchers in different fields, such as biochemistry, agriculture, engineering, biomedicine and environmental science

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 2012-10-04 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 Natural Attenuation of Chlorinated Ethenes by Anaerobic Reductive Dechlorination Coupled with Aerobic Cometabolism written by DEREK. VEERKAMP and published by . This book was released on 1999-03-01 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chlorinated solvents and their daughter products are the most common contaminants of groundwater at industrial and military facilities in the United States. Limitations of conventional technologies have intensified efforts to find alternative methods to remediate contaminated sites to regulatory goals set by CERCLA. Natural attenuation of chlorinated solvents is a promising alternative to traditional pump and treat methods but has not been well understood or widely accepted. This modeling study investigated the ability of TCE to completely degrade under various aquifer conditions and rate order constants. It also examined a case study of a former landfill site at Moody AFB. We found unusually high flow of ground water by advection or dispersion inhibits the complete degradation of TCE. High concentrations of sulfate or nitrate inhibit the creation of methanogenic conditions and therefore inhibit reductive dechlorination of TCE. We also found an electron donor co-contaminant a critical factor for the complete destruction of TCE because it creates anaerobic conditions. The model illustrated a possible explanation for the lack of down gradient contaminants at the landfill site may be the coupling of reductive dechlorination and cometabolism naturally attenuation the contaminants.

Download or read book Handbook of Solvents written by George Wypych and published by ChemTec Publishing. This book was released on 2001 with total page 1446 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive, extensive textual analysis of the principles of solvent selection and use, the handbook is intended to help formulators select ideal solvents, safety coordinators to protect workers, and legislators and inspectors to define and implement technically correct public safeguards for use, handling, and disposal.

Download or read book Advances in In Situ Biological and Chemical Groundwater Treatment written by Sabrina Saponaro and published by MDPI. This book was released on 2020-12-03 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book collects the peer-reviewed contributions accepted for the publication in the Special Issue “Advances in In Situ Biological and Chemical Groundwater Treatment” of the MDPI journal Water. As such, the contributions refer to a variety of widespread pollutants (chlorinated ethenes, chlorinated phenols, chromium, copper, nickel, and arsenic phenols) and new remediation approaches (bioremediation, bioelectrochemical systems, and sorption), covering lab and field studies.

Download or read book Abstracts of the General Meeting of the American Society for Microbiology written by American Society for Microbiology. General Meeting and published by . This book was released on 2008 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Bioremediation written by Mirza Hasanuzzaman and published by Academic Press. This book was released on 2020-10-18 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Bioremediation: Physiological, Molecular and Biotechnological Interventions discusses the mechanisms of responding to inorganic and organic pollutants in the environment using different approaches of phytoremediation and bioremediation. Part One focuses specifically on inorganic pollutants and the use of techniques such as metallothionein-assisted remediation, phytoextraction and genetic manipulation. Part Two covers organic pollutants and consider topics such as plant enzymes, antioxidant defense systems and the remediation mechanisms of different plant species. This comprehensive volume is a must-read for researchers interested in plant science, agriculture, soil science and environmental science. The techniques covered in this book will ensure scientists have the knowledge to practice effective bioremediation techniques themselves. Provides a comprehensive review of the latest advances in bioremediation of organic and inorganic pollutants Discusses a range of different phytoremediation techniques Evaluates the role of genomics and bioinformatics within bioremediation

Download or read book Xenobiotics in the Soil Environment written by Muhammad Zaffar Hashmi and published by Springer. This book was released on 2017-02-15 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the vast variety of xenobiotics, such as pesticides, antibiotics, antibiotic resistance genes, agrochemicals and other pollutants, their interactions with the soil environment, and the currently available strategies and techniques for soil decontamination and bioremediation. Topics covered include: transport mechanisms of pollutants along the Himalayas; use of earthworms in biomonitoring; metagenomic strategies for assessing contaminated sites; xenobiotics in the food chain; phyto-chemical remediation; biodegradation by fungi; and the use of enzymes and potential microbes in biotransformation. Accordingly, the book offers a valuable guide for scientists in the fields of environmental ecology, soil and food sciences, agriculture, and applied microbiology.