Download or read book Microbial Iron Redox Cycling in Terrestrial Environments written by and published by . This book was released on 2014 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial redox cycling of iron (Fe) plays a central role in controlling terrestrial element partitioning, with broader impacts on subsurface contaminant mobility and the development of geochemical cycles on Earth. This dissertation explores the capacity of native microbial communities to oxidize and reduce Fe in terrestrial circumneutral-pH environments by coupling environmental sampling campaigns to bench-top experiments. Microbial Fe-oxide reduction can result in magnetite production, potentially explaining magnetite in Precambrian sedimentary rocks. The only modern analog occurs in sediments at the Bay of Vidy (Lake Geneva, Switzerland), where in situ magnetite formation is directly associated with microbial reduction. Geochemistry and isotope composition of Fe in these sediments was investigated. Despite extensive microbial reduction, very little Fe isotope variation was observed, indicating Fe isotope homogeneity is not sufficient to rule out a biological mechanism for magnetite formation. Microbial oxidation of solid-phase Fe(II) at circumneutral pH is a key pathway in controlling element partitioning and contaminant stability in modern terrestrial environments. Experimental reactors were constructed with sediment from a contaminated subsurface environment (Hanford 300 Area, Richland, WA) to determine how native microbes responded to oxidant flux. Endogenous microbial communities rapidly responded to chemical oxidant input (O2 or NO3) concurrently stabilizing. Uninoculated oxic reactors showed significant Fe(II) oxidation, enhancing our understanding of the capacity for native microbes in subsurface sediment to maintain redox state. A second series of reactors explored the capacity of native microbes to oxidize solid-phase Fe minerals. The first microbial cultures capable of aerobic pyrite (FeS2) oxidation at circumneutral pH were recovered. These enrichment cultures demonstrated growth tied to pyrite oxidation and sulfate generation for over one year of repeated transfers. Aerobic pyrite oxidation has been proposed to be a dominant pathway in Precambrian sulfur cycling. The mineralogical, microbiological, and geochemical changes observed in these experiments shed light on the role of microbes in sulfur cycling in ancient and modern subsurface environments. Finally, my Teaching and Learning Portfolio, the capstone requirement for the Delta Program's Certificate in Research, Teaching, and Learning, is included to highlight some of the broader impacts of my graduate career.

Download or read book The microbial ferrous wheel iron cycling in terrestrial freshwater and marine environments written by David Emerson and published by Frontiers E-books. This book was released on with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past 15 years, there has been steady growth in work relating to the microbial iron cycle. It is now well established that in anaerobic environments coupling of organic matter utilization to Fe reduction is a major pathway for anaerobic respiration. In iron-rich circumneutral environments that exist at oxic-anoxic boundaries, significant progress has been made in demonstrating that unique groups of microbes can grow either aerobically or anaerobically using Fe as a primary energy source. Likewise, in high iron acidic environments, progress has been made in the study of communities of microbes that oxidize iron, and in understanding the details of how certain of these organisms gain energy from Fe-oxidation. On the iron scarcity side, it is now appreciated that in large areas of the open ocean Fe is a key limiting nutrient; thus, a great deal of research is going into understanding the strategies microbial cells, principally phytoplankton, use to acquire iron, and how the iron cycle may impact other nutrient cycles. Finally, due to its abundance, iron has played an important role in the evolution of Earth’s primary biogeochemical cycles through time. The aim of this Research Topic is to gather contributions from scientists working in diverse disciplines who have common interests in iron cycling at the process level, and at the organismal level, both from the perspective of Fe as an energy source, or as a limiting nutrient for primary productivity in the ocean. The range of disciplines may include: geomicrobiologists, microbial ecologists, microbial physiologists, biological oceanographers, and biogeochemists. Articles can be original research, techniques, reviews, or synthesis papers. An overarching goal is to demonstrate the environmental breadth of the iron cycle, and foster understanding between different scientific communities who may not always be aware of one another’s work.

Download or read book Microbial and Geochemical Iron Redox Cycling in Chocolate Pots Hot Springs Yellowstone National Park written by Nathaniel W. Fortney and published by . This book was released on 2018 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrothermal vent systems, both terrestrial and oceanic, are important environments for astrobiological research because of the hypothesized origin of life on Earth occurring at such environments. Recent and increasing evidence for relic vent deposits on Mars has further piqued the interest of astrobiologists and have become the target for future investigations for potential Martian life. While the origin of life is still highly debated, the redox gradients formed near hydrothermal vents and the energetic advantage this gives life living in such environments is undeniable. Hyperthermophilic prokaryotic organisms are phylogenetically deeply rooted, which supports the notion of originating near hydrothermal vents. Furthermore, many of these deeply rooted organisms encode Fe redox cycling based metabolic pathways suggesting dissimilatory Fe reduction (DIR) and Fe(II) oxidation are ancient microbial metabolisms. Chocolate Pots hot springs (CP) are a collection of Fe-rich circumneutral-pH hydrothermal springs located in northwestern Yellowstone National Park. For the past two decades, one of the more prominent features has been investigated with interest in how oxygenic phototrophs (e.g. cyanobacteria) may have contributed to banded iron formation deposition in the Archean. Here we expand on previous enrichment culture based investigations of the putative Fe cycling microbial community by conducting Fe(III)-reducing incubation experiments and collecting sediment and spring water samples directly from CP to gain a better understanding of the composition of the microbial community and its metabolic potential in situ. High DIR activity was observed in samples collected near the hot spring vent, and diminished further downstream. Results from 16S rRNA gene amplicon and shotgun metagenomic sequencing revealed taxa related to Thermodesulfovibrio and Ignavibacteria which encoded putative extracellular electron transfer pathways as potential indication of the in situ Fe(III)-reducing microbial community. Fe isotope fractionation that occurs as a result of DIR has been recognized as a potential biomarker of microbial activity in the rock record and in modern environments. Although natural variability obfuscated results, samples collected from the vent pool and sediment cores revealed fractionation suggestive of DIR. These studies provide constraint on the potential pathways and signatures of both extant and ancient Fe-based microbial life on Earth, Mars, and other rocky planets.

Download or read book Advances in Microbial Iron Cycling written by Lei Yan and published by Frontiers Media SA. This book was released on 2022-07-13 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biogeochemical Cycles written by Katerina Dontsova and published by John Wiley & Sons. This book was released on 2020-04-14 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Elements move through Earth's critical zone along interconnected pathways that are strongly influenced by fluctuations in water and energy. The biogeochemical cycling of elements is inextricably linked to changes in climate and ecological disturbances, both natural and man-made. Biogeochemical Cycles: Ecological Drivers and Environmental Impact examines the influences and effects of biogeochemical elemental cycles in different ecosystems in the critical zone. Volume highlights include: Impact of global change on the biogeochemical functioning of diverse ecosystems Biological drivers of soil, rock, and mineral weathering Natural elemental sources for improving sustainability of ecosystems Links between natural ecosystems and managed agricultural systems Non-carbon elemental cycles affected by climate change Subsystems particularly vulnerable to global change The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals. Book Review: http://www.elementsmagazine.org/archives/e16_6/e16_6_dep_bookreview.pdf

Download or read book Geochemistry of Marine Sediments written by David J. Burdige and published by Princeton University Press. This book was released on 2020-08-04 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The processes occurring in surface marine sediments have a profound effect on the local and global cycling of many elements. This graduate text presents the fundamentals of marine sediment geochemistry by examining the complex chemical, biological, and physical processes that contribute to the conversion of these sediments to rock, a process known as early diagenesis. Research over the past three decades has uncovered the fact that the oxidation of organic matter deposited in sediment acts as a causative agent for many early diagenetic changes. Summarizing and discussing these findings and providing a much-needed update to Robert Berner's Early Diagenesis: A Theoretical Approach, David J. Burdige describes the ways to quantify geochemical processes in marine sediment. By doing so, he offers a deeper understanding of the cycling of elements such as carbon, nitrogen, and phosphorus, along with important metals such as iron and manganese. No other book presents such an in-depth look at marine sediment geochemistry. Including the most up-to-date research, a complete survey of the subject, explanatory text, and the most recent mathematical formulations that have contributed to our greater understanding of early diagenesis, Geochemistry of Marine Sediments will interest graduate students of geology, geochemistry, and oceanography, as well as the broader community of earth scientists. It is poised to become the standard text on the subject for years to come.

Download or read book Iron and Carbon Dynamics in Redox Active Terrestrial Environments written by Jacqueline Mejia and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Terrestrial environments contain one of the largest pools of iron (Fe) and organic carbon (OC), making the interaction between these two elements important drivers of biogeochemical cycles in soils and sediments, and critical for predicting future atmospheric carbon dioxide concentrations and climate change. This dissertation aims to understand the chemical and biological stability of Fe (hydr)oxides and OC in redox dynamic soils and sediments. A series of wet chemical techniques, advanced surface characterization methods and comparative metagenomic approaches were combined to (1) evaluate biogeochemical processes governing Fe (hydr)oxide mineralogical changes during redox oscillations, and (2) explore the biological stability of OC under Fe(III) reducing conditions. In Chapter 2, the mineralogical transformation of lepidocrocite and ferrihydrite was evaluated in the presence of freshwater sediment microorganisms under oscillating Fe(III) reducing (i.e., anaerobic glucose addition) and Fe(II) oxidizing (i.e., oxygen or nitrate addition) conditions. The results illustrate that the flux of different electron donors and acceptors can greatly impact Fe (hydr)oxide transformations and alter Fe, C, and N dynamics taking place in Fe-rich, redox active soils and sediments. Chapter 3 examined whether isolated humic substances could serve as both electron shuttles and electron donors for dissimilatory iron (hydr)oxide reduction (DIR) by freshwater sediment microorganisms. Both humic acid (HA) and humin (HM) were able to shuttle electrons and enhance DIR in cultures amended with glucose, but only HA could donate electrons for DIR by undergoing microbial degradation. Evidence for HA metabolism was observed by an overrepresentation of genes involved in polysaccharide degradation in cultures containing HA compared to those with only glucose. Chapter 4 evaluated the stability of Fe (hydr)oxide-HA coprecipitates under Fe(III) reducing conditions. HA enhanced DIR by serving as an electron shuttle and donor, but significant HA desorption was not observed. These results call into question the role of DIR in Fe (hydr)oxide-bound OC release. Overall, the transformation of Fe (hydr)oxides in redox active environments plays a central role in subsurface biogeochemical processes including nutrient availability, contaminant mobility and carbon dynamics.

Download or read book Microbial Regulation of Soil Carbon Cycling in Terrestrial Ecosystems written by Hui Li and published by Frontiers Media SA. This book was released on 2023-11-15 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Manual of Environmental Microbiology written by Christon J. Hurst and published by American Society for Microbiology Press. This book was released on 2007-05-14 with total page 3023 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most definitive manual of microbes in air, water, and soil and their impact on human health and welfare. • Incorporates a summary of the latest methodology used to study the activity and fate of microorganisms in various environments. • Synthesizes the latest information on the assessment of microbial presence and microbial activity in natural and artificial environments. • Features a section on biotransformation and biodegradation. • Serves as an indispensable reference for environmental microbiologists, microbial ecologists, and environmental engineers, as well as those interested in human diseases, water and wastewater treatment, and biotechnology.

Download or read book Effects of Redox cycling on Iron mineral Transformations and Metatranscriptome of Iron III reducing Bacteria in a Humid Tropical Forest Soil written by Jared Lee Wilmoth and published by . This book was released on 2016 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reactivity of iron(III)-(oxyhydr)oxides toward microbial iron(III)-reduction is dependent on mineral reactive surface area and solubility, properties that can be altered by redox cycling. Because carbon (C) stability and nutrient availability can be influenced by redox dynamics, there is a need to evaluate the mechanisms that govern iron(III)-(oxyhydr)oxide transformations and strategies of microbial iron(III)-reducers to access these phases under fluctuating redox conditions in soils. To do this, we characterized the native iron phases in soils from the Bisley Watershed, Luquillo Critical Zone Observatory (LCZO), PR using selective chemical extractions, X-ray diffraction and 57Fe-Mössbauer spectroscopy. We then conducted laboratory experiments where we exposed the soils to redox cycles with variable iron(II)-oxidation rates and measured changes in the solution and solid phase iron speciation as well as sequenced mRNA extracted from native iron(III)-reducing bacteria. The native iron composition in the LCZO soil comprised goethite and lepidocrocite, with higher solid phase iron(II) correlated with higher lepidocrocite abundance and citrate-ascorbate extractable (low crystallinity) iron. 57Iron-Mössbauer spectra at 140 Kelvin (K) show that iron-(oxyhydr)oxides underwent either an increase or a decrease in crystal order due to rate of iron(II)-oxidation over multiple redox cycles in laboratory incubations. Soil RNA isolated following multiple redox cycles was subsequently depleted of rRNA and enriched for mRNA by linear amplification. De novo assembly of millions of paired-end Illumina reads was used to further examine the importance of several putative c-type cytochrome, pilin, exopolysaccharide, chemotaxis, TCA cycle and carbon degradation transcripts that were collectively binned to iron(III)-reducer genomes of Anaeromyxobacter, Geobacter and Desulfovibrio. We also enriched 57iron in soil incubations to track iron(III)-(oxyhydr)oxide formation. We found that rapid oxidation of enriched iron(II) generates short-range-ordered (i.e. low crystallinity) iron phases that are more readily solubilized by iron(III)-reducing microorganisms than the bulk native soil iron phases at the onset of iron(III)-reduction. Some 57iron-enriched solid iron(III) that is not reduced becomes incorporated into longer-range-order phases (i.e. higher crystallinity) during iron(III)-reduction. A portion of iron(II) formed in the solid phase during iron(III)-reduction displays weak magnetic order in the Mössbauer spectra collected at 4.5 K, perhaps arising from the formation of nano-magnetite or, more generally, iron(II) adsorbed/incorporated at the surface of short-range-ordered iron(III)-(oxyhydr)oxides. These processes regarding mineral-microbial interactions are expected to be linked to ecosystem-level nutrient cycling, carbon stability and global greenhouse gas emissions in highly-active, humid, tropical forest soils.

Download or read book Bridging Environmental Magnetism with Biogeophysics to Study Biogeochemical Processes of Today written by Luigi Jovane and published by Frontiers Media SA. This book was released on 2021-10-21 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cover Image credit: Topic Editor Dr. Andrea Teixeira Ustra

Download or read book Metals Microbes and Minerals The Biogeochemical Side of Life written by Peter Kroneck and published by Walter de Gruyter GmbH & Co KG. This book was released on 2021-01-18 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Ions in Life Sciences links coordination chemistry and biochemistry in their widest sense and thus increases our understanding of the relationship between the chemistry of metals and life processes; in fact, it is an old wisdom that metals are indispensable for life. The series reflects the interdisciplinary nature of Biological Inorganic Chemistry and coordinates the efforts of scientists in numerous interconnecting research fields.

Download or read book Iron Ores and Iron Oxide Materials written by Volodymyr Shatokha and published by BoD – Books on Demand. This book was released on 2018-07-11 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the multidisciplinary reading audience with a comprehensive state-of-the-art overview of research and innovations in the relationship between iron ores and iron ore materials. The book covers industrial sectors dealing with exploration and processing of iron ores as well as with advanced applications for iron ore materials and therefore entails a wide range of research fields including geology, exploration, beneficiation, agglomeration, reduction, smelting, and so on, thus encouraging life cycle thinking across the entire production chain. Iron remains the basis of modern civilization, and our sustainable future deeply depends upon our ability to satisfy the growing demand for iron and steel while decoupling hazardous emissions from economic growth. Therefore, environmental sustainability aspects are also broadly addressed. In response to socioeconomic and climatic challenges, the iron ore sector faces, this book delivers a vision for the new opportunities linked to deployment of the best available, innovative and breakthrough technologies as well as to advanced material applications.

Download or read book Trace Elements in Terrestrial Environments written by Domy C. Adriano and published by Springer Science & Business Media. This book was released on 2013-03-19 with total page 888 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive reference handbook on the important aspects of trace elements in the land environment. Each chapter addresses a particular element and gives a general introduction to their role in the environment, where they come from, and their biogeochemical cycles. In addition to a complete updating of each of the element chapters, this new edition has new chapters devoted to aluminum and iron, soil contamination, remediation and trace elements in aquatic ecosystems. In short, an essential resource for environmental scientists and chemists, regulators and policy makers.

Download or read book Kinetics Thermodynamics and Habitability of Microbial Iron Redox Cycling written by Brian St Clair and published by . This book was released on 2017 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many acidic hot springs in Yellowstone National Park support microbial iron oxidation, reduction, or microbial iron redox cycling (MIRC), as determined by microcosm rate experiments. Microbial dissimilatory iron reduction (DIR) was detected in numerous systems with a pH

Download or read book Encyclopedia of Ecology written by Brian D. Fath and published by Newnes. This book was released on 2014-11-03 with total page 4292 pages. Available in PDF, EPUB and Kindle. Book excerpt: The groundbreaking Encyclopedia of Ecology provides an authoritative and comprehensive coverage of the complete field of ecology, from general to applied. It includes over 500 detailed entries, structured to provide the user with complete coverage of the core knowledge, accessed as intuitively as possible, and heavily cross-referenced. Written by an international team of leading experts, this revolutionary encyclopedia will serve as a one-stop-shop to concise, stand-alone articles to be used as a point of entry for undergraduate students, or as a tool for active researchers looking for the latest information in the field. Entries cover a range of topics, including: Behavioral Ecology Ecological Processes Ecological Modeling Ecological Engineering Ecological Indicators Ecological Informatics Ecosystems Ecotoxicology Evolutionary Ecology General Ecology Global Ecology Human Ecology System Ecology The first reference work to cover all aspects of ecology, from basic to applied Over 500 concise, stand-alone articles are written by prominent leaders in the field Article text is supported by full-color photos, drawings, tables, and other visual material Fully indexed and cross referenced with detailed references for further study Writing level is suited to both the expert and non-expert Available electronically on ScienceDirect shortly upon publication

Download or read book Soil Microbiology Ecology and Biochemistry written by Eldor Paul and published by Academic Press. This book was released on 2014-11-14 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fourth edition of Soil Microbiology, Ecology and Biochemistry updates this widely used reference as the study and understanding of soil biota, their function, and the dynamics of soil organic matter has been revolutionized by molecular and instrumental techniques, and information technology. Knowledge of soil microbiology, ecology and biochemistry is central to our understanding of organisms and their processes and interactions with their environment. In a time of great global change and increased emphasis on biodiversity and food security, soil microbiology and ecology has become an increasingly important topic. Revised by a group of world-renowned authors in many institutions and disciplines, this work relates the breakthroughs in knowledge in this important field to its history as well as future applications. The new edition provides readable, practical, impactful information for its many applied and fundamental disciplines. Professionals turn to this text as a reference for fundamental knowledge in their field or to inform management practices. New section on "Methods in Studying Soil Organic Matter Formation and Nutrient Dynamics" to balance the two successful chapters on microbial and physiological methodology Includes expanded information on soil interactions with organisms involved in human and plant disease Improved readability and integration for an ever-widening audience in his field Integrated concepts related to soil biota, diversity, and function allow readers in multiple disciplines to understand the complex soil biota and their function