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 Bioavailability of Dissolved Organic Matter in Coastal Waters written by Christian Lønborg and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fraction of DOM is coloured containing a part that absorbs (CDOM), and a part that absorbs and reemits the energy again (Fluorescence, FDOM). The relation between the optical properties of DOM and the bioavailability of DOC was tested in the Ría de Vigo. This study demonstrated that it was possible to derive both the bioavailable DOC and its rate constants from the DOM protein-like fluorescence, whereas refractory DOC could be estimated from in situ CDOM and humic-like substances in the Ría de Vigo. Heterotrophic microbes have often been viewed as the main consumers of DOM, but it is now evident that they can also produce DOM. The heterotrophic microbial production of DOM was studied using microbial communities from Loch Creran. The experiments demonstrated that the microbes produced refractory and labile DOM with a coloured signal.
Download or read book Treatise on Estuarine and Coastal Science written by and published by Academic Press. This book was released on 2012-03-06 with total page 4604 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of estuaries and coasts has seen enormous growth in recent years, since changes in these areas have a large effect on the food chain, as well as on the physics and chemistry of the ocean. As the coasts and river banks around the world become more densely populated, the pressure on these ecosystems intensifies, putting a new focus on environmental, socio-economic and policy issues. Written by a team of international expert scientists, under the guidance of Chief Editors Eric Wolanski and Donald McClusky, the Treatise on Estuarine and Coastal Science, Ten Volume Set examines topics in depth, and aims to provide a comprehensive scientific resource for all professionals and students in the area of estuarine and coastal science Most up-to-date reference for system-based coastal and estuarine science and management, from the inland watershed to the ocean shelf Chief editors have assembled a world-class team of volume editors and contributing authors Approach focuses on the physical, biological, chemistry, ecosystem, human, ecological and economics processes, to show how to best use multidisciplinary science to ensure earth's sustainability Provides a comprehensive scientific resource for all professionals and students in the area of estuarine and coastal science Features up-to-date chapters covering a full range of topics
Download or read book Aquatic Ecosystems Interactivity of Dissolved Organic Matter written by Stuart Findlay and published by Academic Press. This book was released on 2003 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overviews of the source, supply and variability of DOM, surveys of the processes that mediate inputs to microbial food webs, and syntheses consolidating research findings provide a comprehensive review of what is known of DOM in freshwater. This book will be important to anyone interested in understanding the fundamental factors associated with DOM that control aquatic ecosystems."--BOOK JACKET.
Download or read book Bioavailability of Dissolved Organic Matter in Coastal Waters written by Christian Lønborg and published by . This book was released on 2009 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fraction of DOM is coloured containing a part that absorbs (CDOM), and a part that absorbs and reemits the energy again (Fluorescence, FDOM). The relation between the optical properties of DOM and the bioavailability of DOC was tested in the Ría de Vigo. This study demonstrated that it was possible to derive both the bioavailable DOC and its rate constants from the DOM protein-like fluorescence, whereas refractory DOC could be estimated from in situ CDOM and humic-like substances in the Ría de Vigo. Heterotrophic microbes have often been viewed as the main consumers of DOM, but it is now evident that they can also produce DOM. The heterotrophic microbial production of DOM was studied using microbial communities from Loch Creran. The experiments demonstrated that the microbes produced refractory and labile DOM with a coloured signal.
Download or read book Concentration and Transport Data for Selected Dissolved Inorganic Constituents and Dissolved Organic Carbon in Water Collected from the Mississippi River and Some of Its Tributaries July 1991 May 1992 written by and published by . This book was released on 1995 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microbial Utilization and Transformation of Dissolved Organic Matter in Aquatic Environments from Streams to the Deep Ocean written by Johanna Sjöstedt and published by Frontiers Media SA. This book was released on 2021-07-28 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nutrient Control Actions for Improving Water Quality in the Mississippi River Basin and Northern Gulf of Mexico written by National Research Council and published by National Academies Press. This book was released on 2009-07-13 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: A large area of coastal waters in the northern Gulf of Mexico experiences seasonal conditions of low levels of dissolved oxygen, a condition known as hypoxia. Excess discharge of nutrients into the Gulf of Mexico from the Mississippi and Atchafalaya rivers causes nutrient overenrichment in the gulf's coastal waters and stimulates the growth of large algae blooms. When these algae die, the process of decomposition depletes dissolved oxygen from the water column and creates hypoxic conditions. In considering how to implement provisions of the Clean Water Act to strengthen nutrient reduction objectives across the Mississippi River basin, the U.S. Environmental Protection Agency (EPA) requested advice from the National Research Council. This book represents the results of the committee's investigations and deliberations, and recommends that the EPA and U.S. Department of Agriculture should jointly establish a Nutrient Control Implementation Initiative to learn more about the effectiveness of actions meant to improve water quality throughout the Mississippi River basin and into the northern Gulf of Mexico. Other recommendations include how to move forward on the larger process of allocating nutrient loading caps-which entails delegating responsibilities for reducing nutrient pollutants such as nitrogen and phosphorus-across the basin.
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 Characterization of Dissolved Organic Matter and Determination of Its Biogeochemical Significance in Coastal and Inland Water Bodies written by M.S. Sankar and published by . This book was released on 2019 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) is a major component of natural waters and provides essential nutrients for aquatic organisms. However, excess DOM in the water results in water quality issues and affects the aquatic life negatively. The present research evaluated the source, composition, reactivity, dynamics, and the spatial distribution of DOM in diverse water bodies using spectrofluorometric methods in tandem with multivariate statistics. The study was conducted in the inland and coastal water bodies of Mississippi, Louisiana, and Alabama over a period of three years (2016 to 2018). Surface water samples were collected from spatially separated waterbodies with diverse land use and land cover classes. In addition, reactivity of DOM was assessed by conducting a series of laboratory experiments at varying magnitudes of sunlight and bacterial activity. Spatial distribution and mobility of DOM, nutrients and trace elements with respect to land cover classes and hydrology was evaluated using watershed delineation and multivariate statistics. Results suggest that microbial humic-like or protein-like DOM compositions derived from microbial/anthropogenic sources were less reactive than the terrestrial humic-like compositions originated from forests and woody wetlands. Furthermore, the sunlight was the major factor causing the degradation of DOM in the water bodies, while temperature had a minor effect. Additionally, the results also suggest that livestock fields in the pastoral and rangelands release a high amount of microbial humic-like DOM along with nutrients such as phosphates and nitrates into the water bodies. Present research identified the presence of four types of DOM in the study areas and were terrestrial humic-like, microbial humic-like, soil-derived humic-like and protein-like compositions. Additionally, trace element availability and mobility of coastal areas is influenced by local hydrology and precipitation. Research also identified forested areas as the major source of DOM to the water bodies of Mississippi. In conclusion, present research found that watershed land use and land cover, hydrology, and climate control the dynamics of DOM, other nutrients, and trace element delivery to the water bodies, while combined effects of light and bacteria are more efficient in reprocessing DOM chemistry within the waterbody.
Download or read book Investigating the Bioavailability of Terrestrial Organic Matter to Marine Microorganisms written by Lindsey Potts and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Terrestrial organic matter is an important source of dissolved organic matter (DOM) to the global ocean, however, the fate and cycling of this DOM is poorly understood. While it is believed that this carbon pool is essential to marine heterotrophic bacteria in pelagic surface waters, several studies attribute variable levels of lability to this DOM fraction. This study attempts to characterize the bioavailability of terrestrial DOM to a marine isolate through carbon isotope analysis of microbially respired carbon dioxide (CO2) using a novel bioreactor system. Potential contributions of background carbon, such as media off-gassing and vitamin additions, were evaluated and characterized to constrain isotopic measurements. Bioreactor incubations using Suwannee River DOM and Vibrio sp. 1A01 yielded rates of carbon respiration rates up to ~0.7 [mu]g C L-1 min-1 and a maximum cell density of ~9.9 x 106 CFU/mL. The [Delta]14C values of respired CO2 fractions were -28.80 to -72.10 suggesting preferential degradation of older organic matter. The [delta]13CCO2 values were -35.30 and -20.90 consistent with degradation of organic matter derived from modern macrophytes as well as aged C3 and C4 plants. The results of this study highlight the utility of carbon isotopes in tracing the origins of labile DOM and shed light on how marine microbes may interact with terrestrial DOM transported to the ocean"--
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 Suspended and dissolved solids effects on freshwater biota written by Darwin L. Sorensen and published by . This book was released on 1977 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flux and Sources of Nutrients in the Mississippi Atchafalaya River Basin written by and published by . This book was released on 1999 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nutrients in the Upper Mississippi River written by and published by . This book was released on 2003 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aquatic Organic Matter Fluorescence written by Paula G. Coble and published by Cambridge University Press. This book was released on 2014-07-14 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: A core text on principles, laboratory/field methodologies, and data interpretation for fluorescence applications in aquatic science, for advanced students and researchers.
Download or read book The Role of Dissolved Organic Matter in Structuring Microbial Community Composition written by Rachel Elizabeth Sipler and published by . This book was released on 2009 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) is an important source of nutrients in aquatic systems contributing to the growth of phytoplankton and bacteria. The overall response appears to be driven by the phytoplankton and bacteria species present as well as the composition of DOM provided. This dissertation explores the bioavailability of allochthonous and autochthonous DOM sources to, and its affect on, the growth of marine phytoplankton and bacterial community abundance and composition. This research utilizes advanced chemical (electrospray ionization mass spectrometry (ESI-MS)) and molecular (terminal restriction fragment length polymorphism (TRFLP)) techniques to characterize the DOM and microbial community. To investigate the role of allochthonous DOM in phytoplankton growth, DOM from two different riverine sources from watersheds with different land use practices, was supplied to a natural cyanobacteria population. The bioavailability of autochthonous DOM was investigated by supplying DOM produced by a single culture of cyanobacteria to a natural dinoflagellate bloom community. The potential negative effect of an individual autochthonous DOM compound was investigated through the addition of marine toxin, brevetoxin, to three different natural bacterial communities. This dissertation resulted in the first ESI-MS characterization spectra of the DOM associated with three different natural phytoplankton blooms, a culture of cyanobacteria, and two different South Florida rivers. It was also the first study to identify previously uncharacterized allochthonous and autochthonous DOM masses bioavailable to natural marine phytoplankton communities. Bulk level analyses within these experiments quantified lower limits for the bioavailability of allochthonous and autochthonous DOM sources and the relative community response to each of these sources. This dissertation also represents the first molecular evaluation of the bacteria associated with a bloom and the first investigation of the allelopathic properties of brevetoxin. It has discussed and applied the use of ESI-MS to investigate the bioavailability of complex DOM, identified and quantified potential nutrient sources and linked marine toxin production to changes in bacterial community composition.
