Download or read book Uptake of Dissolved Organic Matter and Phosphate by Phototrophic and Heterotrophic Bacteria written by Vanessa K. Michelou and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Bacterioplankton communities play a crucial role in marine biogeochemical cycles because they mediate the flux of dissolved organic matter (DOM), which is equal to about half of primary production in the ocean. These bacterial communities are also known to be very diverse and are comprised of bacteria from several different phylogenetic groups. Most biogeochemical studies of marine environments use the dichotomy of grouping microorganisms into two boxes, photoautotrophs and heterotrophs. My dissertation is about organisms and processes not described by these two boxes. An important component of my research work was the identification and quantification of organic matter uptake by marine cyanobacteria Prochlorococcus and Synechococcus. The goal of the first part of my dissertation was to identify the microbial groups responsible for light-dependent leucine incorporation and to examine the effect of light on the uptake of amino acids added at tracer levels. My hypothesis was that stimulation of bacterial production by light was due to photoheterotrophy by Prochlorococcus. My results indicated that this was in fact the case, but other groups of photoheterotrophic bacteria contributed to the light effect as well. The uptake of essential elements in reduced organic forms could provide an additional source of macronutrients to be used in protein synthesis, and help explain the success of Prochlorococcus and Synechococcus in oligorophic environments. These marine cyanobacteria are capable of accessing a wide variety of organic compounds. These results allowed me to hypothesize that these marine cyanobacteria take up dissolved organic matter for limiting elements like nitrogen and phosphorus. To determine if these cyanobacteria were also capable of assimilating non-limiting organic compounds without nitrogen or phosphorus, uptake rates of amino acids and glucose by Prochlorococcus, Synechococcus and heterotrophic bacteria were determined in the Sargasso Sea in May and September of 2008 using flow cytometry. This study revealed that glucose uptake by Synechococcus was significantly higher than uptake by both Prochlorococcus and heterotrophic bacteria in all samples, while uptake by Prochlorococcus and heterotrophic bacteria was similar. These results suggested that coccoid cyanobacteria are competitive at assimilating dissolved organic compounds without nitrogen or phosphorus, though these microbes accounted for a small fraction of total uptake. Phosphorus potentially limits the growth and productivity of microbial communities in many oligotrophic oceans. Both dissolved inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP) could be an important resource in these regimes. Assimilation rates of inorganic and organic phosphorus by marine cyanobacteria and heterotrophic bacteria in the oligotrophic ocean are not well quantified. For the last chapter of my dissertation, I used radioisotope tracers of orthophosphate and ATP combined with flow cytometry sorting to quantify assimilation by heterotrophic bacteria, Prochlorococcus and Synechococcus during the fall of 2007 and 2008 and the spring of 2009 in the western Sargasso Sea. Phosphate and ATP uptake rates were 50-fold and 80-fold higher for Synechococcus compared to the other two groups. However, there was no significant difference between ATP and phosphate uptake by Prochlorococcus and heterotrophic bacteria. Total uptake of phosphate and ATP was dominated by heterotrophic bacteria, while uptake by Prochlorococcus and Synechococcus was a smaller fraction of the total. This coincided with the lower abundance of these cyanobacteria (25% and 2.5% of total prokaryotes respectively) compared to heterotrophic bacteria during my study. Phosphate and ATP turnover was surprisingly similar for the three groups analyzed, suggesting P uptake by marine cyanobacteria is not that different from uptake by heterotrophic bacteria. Collectively, these data suggest that inorganic and organic P play an important role in the ecological success of marine cyanobacteria in the Sargasso Sea. The current study added to the growing information regarding the role of specific bacterial groups, such as cyanobacteria, in DOM assimilation. In particular, this study was the first to unfold the contribution of photoheterotrophic microbes to leucine assimilation in the North Atlantic Ocean. My results not only provided new evidence of carbon uptake by phototrophic picoplankton, they lay the foundation for a number of new interesting questions regarding these extremely successful microorganisms.
Download or read book Investigations on the Role of Dissolved Organic Matter in Determining Ecosystem Structure and Function written by Kelton Ray McKinley and published by . This book was released on 1975 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Nitrogen Fixation written by Jonathan P. Zehr and published by Springer Nature. This book was released on 2021-04-02 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book aims to serve as a centralized reference document for students and researchers interested in aspects of marine nitrogen fixation. Although nitrogen is a critical element in both terrestrial and aquatic productivity, and nitrogen fixation is a key process that balances losses due to denitrification in both environments, most resources on the subject focuses on the biochemistry and microbiology of such processes and the organisms involved in the terrestrial environment on symbiosis in terrestrial systems, or on largely ecological aspects in the marine environment. This book is intended to provide an overview of N2 fixation research for marine researchers, while providing a reference on marine research for researchers in other fields, including terrestrial N2 fixation. This book bridges this knowledge gap for both specialists and non-experts, and provides an in-depth overview of the important aspects of nitrogen fixation as it relates to the marine environment. This resource will be useful for researchers in the specialized field, but also useful for scientists in other disciplines who are interested in the topic. It would provide a possible text for upper division classes or graduate seminars.
Download or read book Examining the Bioavailability of Dissolved Organic Matter and Inorganic Nutrients to Heterotrophic Bacteria in Mississippi Coastal Waters written by Katie Grace Carpenter and published by . This book was released on 2010 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissolved Organic Matter in Lacustrine Ecosystems written by K. Salonen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concentrations of dissolved organic matter (DOM) in lakes are often an order of magnitude greater than concentrations of particulate organic matter; nevertheless, the biogeochemical analysis of DOM is described in only a few textbooks on limnology (most thoroughly by Wetzel). The orgins of dissolved organic substances are largely photosynthetic; DOM is either autochthonously synthesized by littoral and pelagic flora through secretions and autolysis of cellular contents, or allochthonously generated in terrestrial systems of the drainage basin, composing largely of humic substances refractory to rapid microbial degradation. The role of DOM in lacustrine ecosystems, as energy source and system regulator, however, is still poorly known. The aim of this book is: (1) to present state-of-the-art reviews of the role of dissolved autochthonous and allochthonous organic matter in pelagial and littoral zones; and (2) to focus attention on poorly understood but critical topics and hence to provide direction for future research activity.
Download or read book Limnology written by Robert G. Wetzel and published by Academic Press. This book was released on 2001-05-10 with total page 1023 pages. Available in PDF, EPUB and Kindle. Book excerpt: Limnology is the study of the structural and functional interrelationships of organisms of inland waters as they are affected by their dynamic physical, chemical, and biotic environments. Limnology: Lake and River Ecosystems, Third Edition, is a new edition of this established classic text. The coverage remains rigorous and uncompromising and has been thoroughly reviewed and updated with evolving recent research results and theoretical understanding. In addition, the author has expanded coverage of lakes to reservoir and river ecosystems in comparative functional analyses.
Download or read book Biogeochemistry of Marine Dissolved Organic Matter written by Dennis A. Hansell and published by Academic Press. This book was released on 2014-10-02 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine dissolved organic matter (DOM) is a complex mixture of molecules found throughout the world's oceans. It plays a key role in the export, distribution, and sequestration of carbon in the oceanic water column, posited to be a source of atmospheric climate regulation. Biogeochemistry of Marine Dissolved Organic Matter, Second Edition, focuses on the chemical constituents of DOM and its biogeochemical, biological, and ecological significance in the global ocean, and provides a single, unique source for the references, information, and informed judgments of the community of marine biogeochemists. Presented by some of the world's leading scientists, this revised edition reports on the major advances in this area and includes new chapters covering the role of DOM in ancient ocean carbon cycles, the long term stability of marine DOM, the biophysical dynamics of DOM, fluvial DOM qualities and fate, and the Mediterranean Sea. Biogeochemistry of Marine Dissolved Organic Matter, Second Edition, is an extremely useful resource that helps people interested in the largest pool of active carbon on the planet (DOC) get a firm grounding on the general paradigms and many of the relevant references on this topic. Features up-to-date knowledge of DOM, including five new chapters The only published work to synthesize recent research on dissolved organic carbon in the Mediterranean Sea Includes chapters that address inputs from freshwater terrestrial DOM
Download or read book Utilization of Dissolved Organic Carbon by Heterotrophic Bacteria and Protozoa written by James M. Graham and published by . This book was released on 1979 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microbial Communities of Coastal Eutrophic Systems written by Savvas Genitsaris and published by Frontiers Media SA. This book was released on 2021-12-31 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Algal Biology A Commemoration of the Work of Rex Lowe written by R. Jan Stevenson and published by Springer Science & Business Media. This book was released on 2007-12-03 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Algal Biology: A Commemoration of the Work of Rex Lowe was written by students and colleagues of Rex Lowe to acknowledge his esteemed career that included exceptional contributions to research and teaching. Papers in the book cover a variety of topics in algal ecology, focusing on benthic algal ecology in freshwater ecosystems. The studies provide an unusual combination of small-scale experiments and large-scale regional surveys that bridge both basic and applied ecology. Ecologists, limnologists, phycologists, and environmental scientists will find valuable contributions to the development and application of algal research.
Download or read book Photochemical alterations of dissolved organic matter impact on heterotrophic bacteria and carbon cycling in lakes written by Stefan Bertilsson and published by . This book was released on 1999 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Algal Ecology written by and published by Academic Press. This book was released on 1996-06-03 with total page 781 pages. Available in PDF, EPUB and Kindle. Book excerpt: Algae are an important component of aquatic benthic ecosystems because they reflect the health of their environment through their density, abundance, and diversity. This comprehensive and authoritative text is divided into three sections to offer complete coverage of the discussion in this field. The first section introduces the locations of benthic algae in different ecosystems, like streams, large rivers, lakes, and other aquatic habitats. The second section is devoted to the various factors, both biotic and abiotic, that affect benthic freshwater algae. The final section of the book focuses on the role played by algae in a variety of complex freshwater ecosystems. As concern over environmental health escalates, the keystone and pivotal role played by algae is becoming more apparent. This volume in the Aquatic Ecology Series represents an important compilation of the latest research on the crucial niche occupied by algae in aquatic ecosystems. Presents algae as the important player in relation to environmental health Prepared by leading authorities in the field Includes comprehensive treatment of the functions of benthic algae as well as the factors that affect these important aquatic organisms Acts as an important reference for anyone interested in understanding and managing freshwater ecosystems
Download or read book Riverine Ecosystem Management written by Stefan Schmutz and published by Springer. This book was released on 2018-05-08 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book surveys the frontier of scientific river research and provides examples to guide management towards a sustainable future of riverine ecosystems. Principal structures and functions of the biogeosphere of rivers are explained; key threats are identified, and effective solutions for restoration and mitigation are provided. Rivers are among the most threatened ecosystems of the world. They increasingly suffer from pollution, water abstraction, river channelisation and damming. Fundamental knowledge of ecosystem structure and function is necessary to understand how human acitivities interfere with natural processes and which interventions are feasible to rectify this. Modern water legislation strives for sustainable water resource management and protection of important habitats and species. However, decision makers would benefit from more profound understanding of ecosystem degradation processes and of innovative methodologies and tools for efficient mitigation and restoration. The book provides best-practice examples of sustainable river management from on-site studies, European-wide analyses and case studies from other parts of the world. This book will be of interest to researchers in the field of aquatic ecology, river system functioning, conservation and restoration, to postgraduate students, to institutions involved in water management, and to water related industries.
Download or read book Ecology of Harmful Algae written by E. Granéli and published by Springer Science & Business Media. This book was released on 2007-10-04 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Harmful algal can cause a variety of deleterious effects, including the poisoning of fish and shellfish, habitat disruptions for many organisms, water discoloration, beach fouling, and even toxic effects for humans. In this volume, international experts provide an in-depth analysis of harmful algae topics and offer a comprehensive synthesis of the latest research in the field.
Download or read book Boreal Peatland Ecosystems written by R.K. Wieder and published by Springer Science & Business Media. This book was released on 2006-10-16 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first truly ecosystem-oriented book on peatlands. It adopts an ecosystems approach to understanding the world's boreal peatlands. The focus is on biogeochemical patterns and processes, production, decomposition, and peat accumulation, and it provides additional information on animal and fungal diversity. A recurring theme is the legacy of boreal peatlands as impressive accumulators of carbon as peat over millennia.
Download or read book The Interrelation of Carbon Phosphorus in Regulating Heterotrophic and Autotrophic Populations in Aquatic Ecosystems written by Pat C. Kerr and published by . This book was released on 1970 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metabolic Interactions Between Bacteria and Phytoplankton written by Xavier Mayali and published by Frontiers Media SA. This book was released on 2018-06-06 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cycling of energy and elements in aquatic environments is controlled by the interaction of autotrophic and heterotrophic processes. In surface waters of lakes, rivers, and oceans, photosynthetic microalgae and cyanobacteria fix carbon dioxide into organic matter that is then metabolized by heterotrophic bacteria (and perhaps archaea). Nutrients are remineralized by heterotrophic processes and subsequently enable phototrophs to grow. The organisms that comprise these two major ecological guilds are numerous in both numbers and in their genetic diversity, leading to a vast array of physiological and chemical responses to their environment and to each other. Interactions between bacteria and phytoplankton range from obligate to facultative, as well as from mutualistic to parasitic, and can be mediated by cell-to-cell attachment or through the release of chemicals. The contributions to this Research Topic investigate direct or indirect interactions between bacteria and phytoplankton using chemical, physiological, and/or genetic approaches. Topics include nutrient and vitamin acquisition, algal pathogenesis, microbial community structure during algal blooms or in algal aquaculture ponds, cell-cell interactions, chemical exudation, signaling molecules, and nitrogen exchange. These studies span true symbiosis where the interaction is evolutionarily derived, as well as those of indirect interactions such as bacterial incorporation of phytoplankton-produced organic matter and man-made synthetic symbiosis/synthetic mutualism.
