Download or read book Degradation of PAHs by Indigenous Microbes in Contaminated River Sediment written by Tamara R. Diglaw and published by . This book was released on 2004 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Pleurotus Ostreatus on Bioremediation of Polycyclic Aromatic Hydrocarbon Contaminated River Sediment written by Matthew D. Gacura and published by . This book was released on 2009 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this study was to optimize bioremediation of Mahoning River sediment historically contaminated with polycyclic aromatic hydrocarbons (PAHs) using white rot fungi. Pleurotus ostreatus grown on grain (10% v/v) was added to contaminated sediment amended with sawdust (80% v/v), with and without fungal specific nutritional nitrogen (to enhance fungal growth), and with cyclodextrin (to increase PAH availability). Sediment mixtures were incubated in the dark at 25°C for 6 weeks. Sawdust made the sediment more porous, allowed better colonization by fungi, and did not greatly increase volume. Fungal biomass, determined using fluorescent microscopy, indicated initial fungal colonization but then fungal growth was inhibited, likely by toxic metals or high moisture content in the sediment. Growth of unidentified fungi was observed, especially in treatments amended with nitrogen. Total PAH concentrations (in the order of 100 ppm), analyzed using a gas chromatograph mass spectrometer (GCMS), and significantly decreased ~ 50-60% in all treatments, including sediment only controls within the first two weeks. Thus, aerobic degradation by native bacteria and volatilization were likely responsible for most of the observed decreases in PAH concentrations. High heterogeneity of PAHs in this historically contaminated sediment led to high variance between replicates. There was a slight decrease in 5 ring PAHs associated with sediment inoculated with P. ostreatus and also a slight decrease in total PAH concentrations associated with sediment amended with sawdust and cyclodextrin (with or without P. ostreatus). Increased nitrogen did not enhance PAH degradation. Sediment inoculated with P. ostreatus after two weeks, rather than initially, showed better fungal growth and colonization, but PAH data was not yet available. These data indicate there is great potential for bioremediation of PAH contaminated sediment conditions by stimulating indigenous bacteria under aerobic conditions followed by the addition of white rot fungi. However, further testing and optimization is still required.
Download or read book Biodegradation and Bioavailability Studies on Aged Pah contaminated Sediment written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The degradation of PAHs by bacteria indigenous to chronically field-contaminated sediment was investigated, where the sediment served as both the inoculum and the medium containing PAHs. Microbial composition and dynamics under representative conditions were characterized by Denaturing Gradient Gel Electrophoresis (DGGE). Due to the high content of reduced sulfur compounds in the sediment, rapid oxygen depletion and severe acidification resulted from intensive activities of sulfur-oxidizing bacteria affiliated with the genus Thiovulum . Proper use of crushed limestone and an oxygen delivery protocol successfully avoided acidification and satisfied the oxygen demand of the system. With sufficient oxygen, substantial biodegradation of 2-, 3-, 4-, and 5-ring PAHs was achieved, while no appreciable degradation of 6-ring compounds was observed. Phylogenetic analysis of the microbial communities in various aerobic slurries with different additives revealed the selection of species associated with genera Cytophaga and Sphingomonas .Only phenanthrene showed a significant degradation coupled to sulfate reduction. Two dominant species grouped with the genus Bacteroides were probably involved in the degradation. They related to clones involved in the degradation of aromatic hydrocarbons with sulfate as the electron acceptor. Under denitrifying conditions, no appreciable PAH degradation was observed, while the reduction of nitrate to nitrogen occurred stoichiometrically with the production of sulfate. This was due to the absolute dominance of an autotrophic, Thiomicrospira denitrificans -like denitrifier. The addition of ethanol or acetate, as applied, was unable to encourage the dominance of heterotrophic denitrifiers, which was necessary for PAH biodegradation. An XAD-2 assisted desorption assay was developed for assessing the bioavailability of PAHs in the sediment. Its promise was demonstrated by the strong agreement between final residual levels of all the 2-, 3-, and 4-ring PAHs after biodegradation and desorption. This suggests that bioavailability was the factor limiting the biodegradation of these PAHs, and explains why addition of nutrients, co-substrates, or surfactants, as practiced, did not improve the extent of degradation in aerobic systems, although different dominant species resulted in response to these amendments. Mild extractions using certain isopropanol- or ethanol-water solutions could also approximate the bioavailability of PAHs, which, however, require intensive studies of extraction parameters.
Download or read book Microbial Community Structure by Fatty Acid Analysis During Polycyclic Aromatic Hydrocarbon Degradation in River Sediment Augmented with Pleurotus Ostreatus written by Sarala Kumari Sajja and published by . This book was released on 2008 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research was conducted to determine changes in the microbial community in contaminated sediment during fungal remediation of polycyclic aromatic hydrocarbon (PAH) contaminated Mahoning River sediment. The fungus used for remediation was Pleurotus ostreatus, white rot fungi which is capable of degrading a wide range of organic contaminants including PAHs. Microbial community structure was determined using fatty acid profiles from microbial lipids extracted directly from the sediment. Contaminated sediment was collected from Lowellville, OH and was incubated at 25 °C. There were 4 treatments (1 liter of contaminated river sediment) done in duplicate runs as follows: 1) untreated sediment, 2) sediment amended with sawdust, 3) sediment amended with sawdust and augmented with Pleurotus ostreatus and, 4) sediment amended with sawdust, augmented with Pleurotus ostreatus and amended with extra nitrogen after 21 days. At day 0, 21, and 42, lipids were extracted from each treatment (in triplicate). Microbial fatty acids were purified from the lipid extract, methylated and analyzed by GC-MS. The sediment microbial community structure showed great heterogeneity shown as high variability within triplicate samples and as differences between duplicate treatments. Groups of anaerobic bacteria (sulfate reducers and methanogens) persisted throughout the treatments, even though they were exposed to oxygen during mixing and from the surface during the incubation. The abundance of gram negative bacteria, a group of bacteria associated with PAH degradation, showed highest relative abundance on day 42. Even though the microbial structure changed, the microbial biomass (measured as lipid phosphate) remained consistent between triplicate samples and duplicate runs, and changed little during the incubation.
Download or read book Solid Peroxide Stimulated Phenanthrene Removal from Contaminated River Sediment written by Katherine Stuart Schaffnit and published by . This book was released on 2009 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fungi in Bioremediation written by Geoffrey M. Gadd and published by Cambridge University Press. This book was released on 2001-11-15 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: An authoritative account of the application of fungi to the treatment of environmental pollution.
Download or read book Distribution and Dynamics of Pyrene degrading Mycobacteria in Freshwater Sediments Contaminated with Polycyclic Aromatic Hydrocarbons written by and published by . This book was released on 2008 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial biodegradation of polycyclic aromatic hydrocarbons (PAHs) is the primary means of attenuation of these toxic and carcinogenic compounds from contaminated soils and sediments. The documented toxicity and carcinogenicity of many PAHs demands remedial action for PAH-contaminated soils and sediments. This is especially important for historically contaminated sites, where higher molecular weight PAHs (HMW) are recalcitrant. Recently, fast-growing Mycobacteria have been identified that can degrade HMW PAHs, such as pyrene and benzo[a]pyrene. These bacteria have been isolated from a variety of geographical locations, indicating a cosmopolitan distribution. This dissertation work was driven by the need for a better understanding of the ecology, distribution, and dynamics of indigenous microbial populations that can biodegrade PAHs, with an emphasis on Mycobacteria. Both culture-independent molecular approaches and cultivation were used to 1) determine the presence of pyrene-degrading Mycobacterium genotypes and compare dynamics to proteobacterial naphthalene-degradation genotypes; 2) determine the distribution of these genotypes across environments, including different geographical locations (Chattanooga Creek and Lake Erie) and different physical environments (sediments vs. suspended particles); and 3) provide a link between functional pyrene genotypes and phylogenetic identity of isolated pyrene-degrading organisms. The results of these studies indicate the pyrene-degrading Mycobacteria have broad, cosmopolitan distribution in contaminated sediments and suspended particles. Isolation of pyrene-degrading organisms from both Chattanooga Creek and Lake Erie has provided strong evidence for horizontal transfer of pyrenedegrading genes between diverse genera. This work demonstrates the prevalence of pyrene-degrading organisms in contaminated sediments and implicates an integral role in natural attenuation of HMW PAHs.
Download or read book Cytochrome P450 written by Paul R. Ortiz de Montellano and published by Springer Science & Business Media. This book was released on 2007-02-05 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cytochrome P450: Structure, Mechanism, and Biochemistry, third edition is a revision of a review that summarizes the current state of research in the field of drug metabolism. The emphasis is on structure, mechanism, biochemistry, and regulation. Coverage is interdisciplinary, ranging from bioinorganic chemistry of cytochrome P450 to its relevance in human medicine. Each chapter provides an in-depth review of a given topic, but concentrates on advances of the last 10 years.
Download or read book Polycyclic Aromatic Hydrocarbons PAHs written by Mohammad Osama and published by . This book was released on 2009 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: White rot fungi, Pleurotus ostreatus, is capable of degrading a wide range of organic contaminants including PAHs. Bioremediating polycyclic aromatic hydrocarbons (PAH) contaminated river sediment with P. ostreatus maybe a viable and less invasive method to reduce risk of exposure. The first part of this research was to determine the degradation of PAHs from contaminated sediment. The second part was to determine if sterols (ergosterol) and PAHs can be extracted with a single extraction method. Ergosterol is produced by living fungi and can be used as a measurement of fungal biomass. Contaminated river sediments were treated with P. ostreatus, grown on barley, and various amendments then incubated at 25 °C. Amendments included sawdust and nitrogen supplement to stimulate fungal growth. The treatment with P. ostreatus showed degradation of total PAHs after 21 days using a Lipid Extraction Method and GC/MS. These results show that P. ostreatus is able to colonize in highly contaminated Mahoning River sediment and degrade the PAHs present. To extract ergosterol and PAHs simultaneously an Ergosterol Extraction Method (EEM) was developed. Various samples were prepared with sediment, sediment and fungi grown on barley, sediment and fungi grown on potato dextrose agar (PDA) or only fungi grown on PDA or barley. The EEM was successful in extracting ergosterol from fungi grown on barley resulting in concentrations from 17.5 - 39.9 mcg/g ergosterol. Similar results were seen in the other treatments. PAHs were also found extracted in much greater amounts compared to the Lipid Extraction Method. In addition, cholesterol, usually found in animals, was detected in the fungi P. ostreatus at easily detectable levels. With better optimization of amendments, Ergosterol Extraction Method could be highly useful and effective in analyzing the level of fungal biomass as well as PAH contaminants during bioremediation efforts.
Download or read book Methods in Applied Soil Microbiology and Biochemistry written by Kassem Alef and published by Academic Press. This book was released on 1995-07-11 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quality control and quality assurance in applied soil microbiology and biochemistry. Soil sampling, handling, storage and analysis. Enrichment, isolation and counting of soil microrganisms. Anaerobic microbial activities in soil. Enzyme activities. Microbial biomass. Community structure. Field methods. Bioremediation of soil.
Download or read book Microbial Degradation of Xenobiotics written by Shree Nath Singh and published by Springer Science & Business Media. This book was released on 2011-10-07 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our interest in the microbial biodegradation of xenobiotics has increased many folds in recent years to find out sustainable ways for environmental cleanup. Bioremediation and biotransformation processes harness the naturally occurring ability of microbes to degrade, transform or accumulate a wide range of organic pollutants. Major methodological breakthroughs in recent years through detailed genomic, metagenomic, proteomic, bioinformatic and other high-throughput analyses of environmentally relevant microorganisms have provided us unprecedented insights into key biodegradative pathways and the ability of organisms to adapt to changing environmental conditions. The degradation of a wide spectrum of organic pollutants and wastes discharged into the environment by anthropogenic activities is an emerging need today to promote sustainable development of our society with low environmental impact. Microbial processes play a major role in the removal of recalcitrant compounds taking advantage of the astonishing catabolic versatility of microorganisms to degrade or transform such compounds. New breakthroughs in sequencing, genomics, proteomics, bioinformatics and imaging are generating vital information which opens a new era providing new insights of metabolic and regulatory networks, as well as clues to the evolution of degradation pathways and to the molecular adaptation strategies to changing environmental conditions. Functional genomic and metagenomic approaches are increasing our understanding of the relative importance of different pathways and regulatory networks to carbon flux in particular environments and for particular compounds. New approaches will certainly accelerate the development of bioremediation technologies and biotransformation processes in coming years for natural attenuation of contaminated environments
Download or read book Investigation of Two Microbial Delivery Systems for the in Situ Bioremediation of PAH Contaminated River Sediment written by Don C. Haddox and published by . This book was released on 2000 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biodegradation and Bioremediation written by Ajay Singh and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this volume, experts from universities, government labs and industry share their findings on the microbiological, biochemical and molecular aspects of biodegradation and bioremediation. The text covers numerous topics, including: bioavailability, biodegradation of various pollutants, microbial community dynamics, properties and engineering of important biocatalysts, and methods for monitoring bioremediation processes. Microbial processes are environmentally compatible and can be integrated with non-biological processes to detoxify, degrade and immobilize environmental contaminants.
Download or read book Advances in Environmental Biotechnology written by Raman Kumar and published by Springer. This book was released on 2017-04-19 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book aims to provide a comprehensive view of advanced environmental approaches for wastewater treatment, heavy metal removal, pesticide degradation, dye removal, waste management, microbial transformation of environmental contaminants etc. With advancements in the area of Environmental Biotechnology, researchers are looking for the new opportunities to improve quality standards and environment. Recent technologies have given impetus to the possibility of using renewable raw materials as a potential source of energy. Cost intensive and eco-friendly technology for producing high quality products and efficient ways to recycle waste to minimize environmental pollution is the need of hour. The use of bioremediation technologies through microbial communities is another viable option to remediate environmental pollutants, such as heavy metals, pesticides and dyes etc. Since physico-chemical technologies employed in the past have many potential drawbacks including higher cost, and lower sustainability. So there is need of efficient biotechnological alternatives to overcome increasing environmental pollution. Hence, there is a need for environmental friendly technologies that can reduce the pollutants causing adverse hazards on humans and surrounding environment.
Download or read book Soil and Sediment Remediation written by Piet Lens and published by IWA Publishing. This book was released on 2005-09-30 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil and Sediment Remediation discusses in detail a whole set of remediative technologies currently available to minimise their impact. Technologies for the treatment of soils and sediments in-situ (landfarming, bioscreens, bioventing, nutrient injection, phytoremediation) and ex-situ (landfarming, bio-heap treatment, soil suspension reactor) will be discussed. The microbiological, process technological and socio-economical aspects of these technologies will be addressed. Special attention will be given to novel biotechnological processes that utilise sulfur cycle conversions, e.g. sulfur and heavy metal removal from soils. Also the potential of phytoremediation will be highlighted. In addition, treatment schemes for the clean-up of polluted megasites, e.g. harbours and Manufactured Gaswork Plants (MGP), will be elaborated. The aim of Soil and Sediment Remediation is to introduce the reader in: the biogeochemical characteristics of soil and sediments- new techniques to study soil/sediment processes (molecular probes, microelectrodes, NMR) clean up technologies for soils polluted with organic (PAH, NAPL, solvents) or inorganic (heavy metals) pollutants- preventative and remediative strategies and technologies available in environmental engineering novel process applications and bioreactor designs for bioremediation the impact of soil pollution on society and its economic importance.
Download or read book Soil Contamination written by Marcelo Larramendy and published by BoD – Books on Demand. This book was released on 2016-12-21 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited book, Soil Contamination - Current Consequences and Further Solutions, is intended to provide an overview on the different environmental consequences of our anthropogenic activities, which has introduced a large number of xenobiotics that the soil cannot, or can only slower, decompose or degrade. We hope that this book will continue to meet the expectations and needs of all interested in diverse fields with expertise in soil science, health, toxicology, and other disciplines who contribute and share their findings to take this area forward for future investigations.
