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 Linking Structure and Function to Manage Microbial Communities Carrying Out Chlorinated Ethene Reductive Dechlorination written by Michal Ziv-El and published by . This book was released on 2012 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contamination by chlorinated ethenes is widespread in groundwater aquifers, sediment, and soils worldwide. The overarching objectives of my research were to understand how the bacterial genus Dehalococcoides function optimally to carry out reductive dechlorination of chlorinated ethenes in a mixed microbial community and then apply this knowledge to manage dechlorinating communities in the hydrogen-based membrane biofilm reactor (MBfR). The MBfR is used for the biological reduction of oxidized contaminants in water using hydrogen supplied as the electron donor by diffusion through gas-transfer fibers. First, I characterized a new anaerobic dechlorinating community developed in our laboratory, named DehaloR^2, in terms of chlorinated ethene turnover rates and assessed its microbial community composition. I then carried out an experiment to correlate performance and community structure for trichloroethene (TCE)-fed microbial consortia. Fill-and-draw reactors inoculated with DehaloR^2 demonstrated a direct correlation between microbial community function and structure as the TCE-pulsing rate was increased. An electron-balance analysis predicted the community structure based on measured concentrations of products and constant net yields for each microorganism. The predictions corresponded to trends in the community structure based on pyrosequencing and quantitative PCR up to the highest TCE pulsing rate, where deviations to the trend resulted from stress by the chlorinated ethenes. Next, I optimized a method for simultaneous detection of chlorinated ethenes and ethene at or below the Environmental Protection Agency maximum contaminant levels for groundwater using solid phase microextraction in a gas chromatograph with a flame ionization detector. This method is ideal for monitoring biological reductive dechlorination in groundwater, where ethene is the ultimate end product. The major advantage of this method is that it uses a small sample volume of 1 mL, making it ideally suited for bench-scale feasibility studies, such as the MBfR. Last, I developed a reliable start-up and operation strategy for TCE reduction in the MBfR. Successful operation relied on controlling the pH-increase effects of methanogenesis and homoacetogenesis, along with creating hydrogen limitation during start-up to allow dechlorinators to compete against other microorgansims. Methanogens were additionally minimized during continuous flow operation by a limitation in bicarbonate resulting from strong homoacetogenic activity.
Download or read book Characterization of Anaerobic Dechlorinating Enrichment Cultures Maintained on Different Chlorinated Ethenes written by Stephan Dieter Wehr and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An anaerobic mixed microbial culture previously enriched from soil and groundwater contaminated with trichloroethene (TCE) was divided into four subcultures amended separately with either perchloroethene (PCE), TCE, ' cis'-dichloroethene ('cis'-DCE) or vinyl chloride (VC). The sustained and complete conversion of chloroethenes, including VC, to ethene was observed in all subcultures. Differences in rates and community composition developed between the different subcultures, including the loss of the VC enrichment culture's ability to dechlorinate PCE. Results of denaturing gradient gel electrophoresis using 16S ribosomal RNA (rRNA) genes indicated that three different organisms, all related to 'Dehalococcoides ethenogenes', were present in all four subcultures. Molecular cloning and sequencing of 16S rRNA genes identified further similarities and differences in community composition between the VC and TCE enrichment subcultures. Due to biases in DNA amplification, further molecular cloning efforts are required to completely characterize the enrichment subcultures.
Download or read book The Effects of Fe III Reduction on Biodegradation of Fuel Oxygenates and Chlorinated Ethenes written by Na Wei and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA), and chlorinated ethenes (TCE, cis-DCE and VC) are two groups of contaminants prevalent in groundwater systems. Fe(III) reducing conditions are dominant in many sedimentary environments. However, the effects of Fe(III) reduction on biotransformation of MTBE/TBA and chlorinated ethenes are not well understood. This research investigated the biodegradation of these contaminants and related microbial ecology under Fe(III)-reducing conditions in both sediment microcosms and enrichment cultures. The primary limitation to understanding anaerobic MTBE biodegradation is the lack of liquid cultures with consistent activity. This study enriched three distinct MTBE-degrading, anaerobic cultures from contaminated aquifer material, and they use anthraquinone-2,6-disulfonate, sulfate and fumarate as the terminal electron acceptor, respectively. Phylogenetic analyses based on 16S rRNA gene suggested novel microorganisms involved in anaerobic MTBE biodegradation. These cultures are the first stable, sediment-free anaerobic MTBE-degrading cultures, which provide model systems for mechanistic studies of anaerobic MTBE biodegradation. Substantial [U-14C]-TBA mineralization occurred under Fe(III)-reducing conditions. The TBA biodegradation activity was correlated with the abundance of one dominant clone, which is closely associated with organisms belonging to the Alphaproteobacteria. The results provide the original evidence of the stimulative effect of Fe(III) reduction on anaerobic TBA mineralization, and give initial insight to the organisms that may catalyze the anaerobic TBA mineralization reactions. The experimental study on the effects of Fe(III) reduction on reductive dechlorination demonstrated that Fe(III) reduction did not inhibit complete dechlorination, which is in contrast to the common opinion that TCE dechlorination will be inhibited wherever there is bioavailable Fe(III). Fe(III) speciation has an impact on daughter product distribution and dechlorination kinetics. Quantitative PCR analysis revealed that Dehalococcoides and Geobacteraceae organisms were enriched concurrently in the dechlorinating Fe(III)-reducing sediments/cultures; Dehalococcoides abundance in the presence of Fe(III) was not significantly different from that in the cultures without Fe(III), meaning Fe(III) reducers would not outcompete and inhibit Dehalococcoides growth. Also, Fe(III) reduction may stimulate growth of G. lovleyi like organisms and contribute to TCE dechlorination to cis-DCE. Enrichment culture study demonstrated that Fe(III) reduction poised the hydrogen concentration at an appropriate steady-state that is within the ideal range for reductive dechlorination when acetate was amended as the sole electron donor. 10X excessive electron donor addition did not facilitate chlorinated ethene dechlorination, but led to considerably high methane production and enrichment of methanogens. The results suggest that adding surplus electron donor will not only cause substrate wastage and unnecessary cost in bioremediation, but also have adverse effects such as enhanced methane release.
Download or read book Chemical Biomarkers in Aquatic Ecosystems written by Thomas S. Bianchi and published by Princeton University Press. This book was released on 2011-02-28 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook provides a unique and thorough look at the application of chemical biomarkers to aquatic ecosystems. Defining a chemical biomarker as a compound that can be linked to particular sources of organic matter identified in the sediment record, the book indicates that the application of these biomarkers for an understanding of aquatic ecosystems consists of a biogeochemical approach that has been quite successful but underused. This book offers a wide-ranging guide to the broad diversity of these chemical biomarkers, is the first to be structured around the compounds themselves, and examines them in a connected and comprehensive way. This timely book is appropriate for advanced undergraduate and graduate students seeking training in this area; researchers in biochemistry, organic geochemistry, and biogeochemistry; researchers working on aspects of organic cycling in aquatic ecosystems; and paleoceanographers, petroleum geologists, and ecologists. Provides a guide to the broad diversity of chemical biomarkers in aquatic environments The first textbook to be structured around the compounds themselves Describes the structure, biochemical synthesis, analysis, and reactivity of each class of biomarkers Offers a selection of relevant applications to aquatic systems, including lakes, rivers, estuaries, oceans, and paleoenvironments Demonstrates the utility of using organic molecules as tracers of processes occurring in aquatic ecosystems, both modern and ancient
Download or read book Conserving Bogs written by Rob E. Stoneman and published by Stationery Office Books (TSO). This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bogs are fascinating landscapes for ecologists, climatologists, archaeologists, environmental historians and water managers. But many bogs have been damaged, and legislative protection - as 29 case studies demonstrate - is not enough to conserve the rest.
Download or read book Microbial Strategies for Crop Improvement written by Mohammad Saghir Khan and published by Springer Science & Business Media. This book was released on 2009-08-25 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: With an ever-increasing human population, the demand placed upon the agriculture sector to supply more food is one of the greatest challenges for the agrarian community. In order to meet this challenge, environmentally unfriendly agroch- icals have played a key role in the green revolution and are even today commonly recommended to circumvent nutrient de?ciencies of the soils. The use of ag- chemicals is, though, a major factor for improvement of plant production; it causes a profound deteriorating effect on soil health (soil fertility) and in turn negatively affects the productivity and sustainability of crops. Concern over disturbance to the microbial diversity and consequently soil fertility (as these microbes are involved in biogeochemical processes), as well as economic constraints, have prompted fun- mental and applied research to look for new agro-biotechnologies that can ensure competitive yields by providing suf?ciently not only essential nutrients to the plants but also help to protect the health of soils by mitigating the toxic effects of certain pollutants. In this regard, the role of naturally abundant yet functionally fully unexplored microorganisms such as biofertilizers assume a special signi?cance in the context of supplementing plant nutrients, cost and environmental impact under both conventional practices and derelict environments. Therefore, current devel- ments in sustainability involve a rational exploitation of soil microbial communities and the use of inexpensive, though less bio-available, sources of plant nutrients, which may be made available to plants by microbially-mediated processes.
Download or read book Cold Adapted Organisms written by Rosa Margesin and published by Springer Science & Business Media. This book was released on 1999-05-06 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Major parts of the oceans and lands of our planet are permanently, or temporarily, exposed to temperatures below 10 C. Microorganisms, plants and animals living under these conditions have adapted to their environments in such a way that metabolic processes, reproduction and survival strategies are optimal for their natural biotopes. This book presents the most recent knowledge of the ecology and the physiology of cold-adapted microorganisms, plants and animals, and explains the mechanisms of cold-adaptation on the enzymatic and molecular level, including results from the first crystal structures of enzymes of cold-adapted organisms.
Download or read book Endospore forming Soil Bacteria written by Niall A. Logan and published by Springer Science & Business Media. This book was released on 2011-07-06 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerobic endospore-forming bacteria are found in soils of all kinds, ranging from acid to alkaline, hot to cold, and fertile to desert. It is well known that endospores confer special properties upon their owners and play dominant parts in their life cycles and dispersal, and much has been written about the spores, genetics, and economic importance of these organisms. Much has also been written about soil ecology, but there is a relative dearth of literature that brings together different aspects of the behaviour and characters of endospore-formers with their contributions to soil ecosystems. This Soil Biology volume fills that gap. Following chapters that describe the current classification of these organisms, that review methods for their detection and for studying their life cycles in soils, and that examine their dispersal, other chapters show that they are active and dynamic members of soil floras that interact widely with other soil inhabitants, with roles in nitrogen fixation, denitrification, and soil remediation.
Download or read book Metal Nanoparticles in Microbiology written by Mahendra Rai and published by Springer Science & Business Media. This book was released on 2011-04-02 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Following an introduction to biogenic metal nanoparticles, this book presents how they can be biosynthesized using bacteria, fungi and yeast, as well as their potential applications in biomedicine. It is shown that the synthesis of nanoparticles using microbes is eco-friendly and results in reproducible metal nanoparticles of well-defined sizes, shapes and structures. This biotechnological approach based on the process of biomineralization exploits the effectiveness and flexibility of biological systems. Chapters include practical protocols for microbial synthesis of nanoparticles and microbial screening methods for isolating a specific nanoparticle producer as well as reviews on process optimization, industrial scale production, biomolecule-nanoparticle interactions, magnetosomes, silver nanoparticles and their numerous applications in medicine, and the application of gold nanoparticles in developing sensitive biosensors.
Download or read book Biogenesis of Hydrocarbons written by Alfons J. M. Stams and published by Springer. This book was released on 2019-08-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book covers the microbiological, environmental and biotechnological aspects of alkane production. Alkanes are important energy-rich compounds on earth. Microbial synthesis of methane and other alkanes is an essential part of the geochemical cycling of carbon and offers perspectives for our biobased economy. This book discusses different aspects of current knowledge of microbial alkane production. Chapters with state of the art information are written by renowned scientists in the field. The chapters are organised into four themed parts:1. Biochemistry of Biogenesis - Hydrocarbons2. Taxonomy, Ecophysiology and Genomics of Biogenesis - Hydrocarbons3. Biogenic Communities: Members, Functional Roles4. Global Consequences of Methane Production
Download or read book Bio Geo Interactions in Metal Contaminated Soils written by Erika Kothe and published by Springer Science & Business Media. This book was released on 2012-01-05 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal contamination is an increasing ecological and eco-toxicological risk. Understanding the processes involved in metal mobilization, sorption and mineralization in soils are key features for soil bioremediation. Following an introduction to the physical, chemical and biological components of contaminated soils, various chapters address the interactions of soil, microorganisms, plants and the water phase necessary to transfer metals into biological systems. These include topics such as potential hazards at mining sites; rare earth elements in biotic and abiotic acidic systems; manganese redox reactions; biomineralisation, uranium in seepage water; metal-resistant streptomycetes; mycorrhiza in re-forestation; metal (hyper)accummulation in plants; microbial metal uptake; and their potential for bioremediation. This book will be of interest to soil biologists, geologists and chemists, researchers and graduate students, as well as consulting companies and small enterprises involved in bioremediation.
Download or read book Innovative Approaches to the On Site Assessment and Remediation of Contaminated Sites written by Danny Reible and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: 2 DANNY D. REIBLEI AND KATERINA DEMNEROVA 1 Hazardous Substance Research Center/South and Southwest, Louisiana State University, Baton Rouge, LA 70803 2 Department of Biochemistry and Microbiology, Institute of Chemical Technology, Prague, Czech Republic On May 24, 2001, a total of 102 students and lecturers participated in an Advanced Study Institute (ASI) sponsored by the North Atlantic Treaty Organization (NATO) under our direction. The Institute was focused on in situ and onsite management of contaminated sites. The objective of the Institute was to balance state of the art science with techniques for field application of a variety of technologies for in situ assessment and remediation of contaminated sites. Many of the lecturers were drawn from the ranks of the Hazardous Substance Research Centers, multi-university consortia that have been funded by the US Environmental Protection Agency to conduct research and technology transfer designed to promote risk-based management and control of hazardous substances for the nation. The Centers have made special contributions to the areas of in situ and onsite assessment and remediation of contaminated sites. Such approaches have the potential for being significantly less expensive than other assessment and remediation approaches while maintaining accuracy and effectiveness. Cost-effective remedial and management approaches that are also effective in minimizing exposure and risk to human health and the environment are a critical need throughout the world but particularly in Eastern Europe and the former Soviet Union where resources that can be devoted to environmental cleanup are especially limited.
Download or read book Urban Land written by Dieter D. Genske and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Urban land is an environmental key topic considering the increasing urbani sation of our world. The amounting pressure on resources especially in the urban environment demand awareness across technical and political sectors and solid concepts for workable solutions. This book will address those people, who are key in coping with the challenges of sustainable urban land use management: Professionals in the growing field of urban land recycling and graduate students from different disciplines including urban planning, environmental sciences and geotechnics. Processes that lead to urban land degradation include the extraction of resources, their transformation into goods, the production of waste and conflicts in the allocation of land. Industrial soil pollution, soil sealing and urban sprawl pose serious challenges to resource management in urban environments. The possible implications are not necessarily restricted to the urban area but do have feedback into the countryside. The reduction of arable land in urban peripheries often causes enhanced pressure on back-country natural ecosystems such as forests, grass- and wetlands. Urban land recycling especially in the developing world is to be seen in the context of poverty alleviation and sustainable development. Ifwe don't get a proper sustainable use of urban land, as well as of water and other natural resources that relate to them, sustainable development will not be reached.
Download or read book The Commercial Storage of Fruits Vegetables and Florist and Nursery Stocks written by Robert E. Hardenburg and published by . This book was released on 1986 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Note for the electronic edition: This draft has been assembled from information prepared by authors from around the world. It has been submitted for editing and production by the USDA Agricultural Research Service Information Staff and should be cited as an electronic draft of a forthcoming publication. Because the 1986 edition is out of print, because we have added much new and updated information, and because the time to publication for so massive a project is still many months away, we are making this draft widely available for comment from industry stakeholders, as well as university research, teaching and extension staff.
Download or read book Current Advances in Anaerobic Digestion Technology written by Marcell Nikolausz and published by MDPI. This book was released on 2021-03-17 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anaerobic digestion (AD) is one of the oldest biotechnological processes and originally referred to biomass degradation under anoxic conditions in both natural and engineered systems. It has been used for decades to treat various waste streams and to produce methane-rich biogas as an important energy carrier, and it has become a major player in electrical power production. AD is a popular, mature technology, and our knowledge about the influencing process parameters as well as about the diverse microbial communities involved in the process has increased dramatically over the last few decades. To avoid competition with food and feed production, the AD feedstock spectrum has constantly been extended to waste products either rich in recalcitrant lignocellulose or containing inhibitory substances such as ammonia, which requires application of various pre-treatments or specific management of the microbial resources. Extending the definition of AD, it can also convert gases rich in hydrogen and carbon dioxide into methane that can substitute natural gas, which opens new opportunities by a direct link to traditional petrochemistry. Furthermore, AD can be coupled with emerging biotechnological applications, such as microbial electrochemical technologies or the production of medium-chain fatty acids by anaerobic fermentation. Ultimately, because of the wide range of applications, AD is still a very vital field in science. This Special Issue highlights some key topics of this research field.
Download or read book Plastics from Bacteria written by George Guo-Qiang Chen and published by Springer Science & Business Media. This book was released on 2009-12-02 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the possibility that petroleum supplies will be exhausted in the next decades to come, more and more attention has been paid to the production of bacterial pl- tics including polyhydroxyalkanoates (PHA), polylactic acid (PLA), poly(butylene succinate) (PBS), biopolyethylene (PE), poly(trimethylene terephthalate) (PTT), and poly(p-phenylene) (PPP). These are well-studied polymers containing at least one monomer synthesized via bacterial transformation. Among them, PHA, PLA and PBS are well known for their biodegradability, whereas PE, PTT and PPP are probably less biodegradable or are less studied in terms of their biodegradability. Over the past years, their properties and appli- tions have been studied in detail and products have been developed. Physical and chemical modifications to reduce their cost or to improve their properties have been conducted. PHA is the only biopolyester family completely synthesized by biological means. They have been investigated by microbiologists, molecular biologists, b- chemists, chemical engineers, chemists, polymer experts, and medical researchers for many years. PHA applications as bioplastics, fine chemicals, implant biomate- als, medicines, and biofuels have been developed. Companies have been est- lished for or involved in PHA related R&D as well as large scale production. It has become clear that PHA and its related technologies form an industrial value chain in fermentation, materials, feeds, and energy to medical fields.
