Download or read book Linkages Between Molecular Composition Bioavailability and Microbial Utilization of Dissolved Organic Matter in the Western Arctic Ocean written by Jenny Davis (Ph. D.) and published by . This book was released on 2007 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biogeochemistry of Marine Dissolved Organic Matter written by Dennis A. Hansell and published by Elsevier. This book was released on 2024-07-04 with total page 870 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biogeochemistry of Marine Dissolved Organic Matter, 3rd edition is the most up-to-date revision of the fundamental reference for the biogeochemistry of marine dissolved organic matter. Since its original publication in June 2002, the science, questions, and priorities have advanced, and the editors of this essential guide, have added nine new chapters, including one on the South China Sea. An indispensable manual edited by the most distinguished experts in the field, this book is addressed to graduate students, marine scientists, and all professionals interested in advancing their knowledge of the field. Features up-to-date knowledge on DOM, including 9 new chapters Presents the only published work to synthesize recent research on dissolved organic carbon in the South China, a region receiving a great deal of attention in recent decades Offers contributions by world-class research leaders
Download or read book Linking Optical and Chemical Properties of Dissolved Organic Matter in Natural Waters written by Christopher L. Osburn and published by Frontiers Media SA. This book was released on 2017-01-17 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: A substantial increase in the number of studies using the optical properties (absorbance and fluorescence) of dissolved organic matter (DOM) as a proxy for its chemical properties in estuaries and the coastal and open ocean has occurred during the last decade. We are making progress on finding the actual chemical compounds or phenomena responsible for DOM’s optical properties. Ultrahigh resolution mass spectrometry, in particular, has made important progress in making the key connections between optics and chemistry. But serious questions remain and the last major special issue on DOM optics and chemistry occurred nearly 10 years ago. Controversies remain from the non-specific optical properties of DOM that are not linked to discrete sources, and sometimes provide conflicting information. The use of optics, which is relatively easier to employ in synoptic and high resolution sampling to determine chemistry, is a critical connection to make and can lead to major advances in our understanding of organic matter cycling in all aquatic ecosystems. The contentions and controversies raised by our poor understanding of the linkages between optics and chemistry of DOM are bottlenecks that need to be addressed and overcome.
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 Structure and Function of Microbial Communities Processing Dissolved Organic Matter in Marine Environments written by Hila Elifantz and published by . This book was released on 2007 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current study added to the growing information regarding the composition of bacterial community in aquatic environments and the role of specific bacterial groups in DOM assimilation. In particular, this study was the first to unfold the relation between structure and function of the bacterial community in the Arctic Ocean, the only cold environment studied in that aspect to date. The molecular study of GH5 revealed the potential of the community for polysaccharides degradation, however, more need to be done to broaden our understanding of the mineralization of these compounds in the marine environment.
Download or read book Dissolved Organic Matter Dynamics in an Arctic Catchment written by Kristin Eulene Judd and published by . This book was released on 2004 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
Download or read book Aquatic Ecosystems Interactivity of Dissolved Organic Matter written by and published by Elsevier. This book was released on 2002-11-06 with total page 533 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aquatic Ecosystems explains the interplay between various movements of matter and energy through ecosystems mediated by Dissolved Organic Matter. This book provides information on how much DOM there is in a particular aquatic ecosystem and where it originates. It explains whether the DOM composition varies from time to time and place to place. It also details how DOM becomes incorporated into microbial food webs, and gives a better, clarifying, understanding to its significance of DOM. There are many ways to study DOM and this book focuses on several central questions: How much DOM is there in a particular aquatic ecosytem? Where does it come from? Does the composition of the DOM vary from time to time and place to palce? How does DOM become incorporated into microbial food webs, which are the basis of plant, invertebrate and vertebrate food webs? How can the answers to these and other questions about DOM be considered together so that a better understanding of the significance of DOM can emerge?
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 From Freshly Produced Compounds to Refractory Molecules written by Helena Osterholz and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis includes the results of two field studies and one laboratory incubation experiment focusing on the production and turnover of freshly produced dissolved organic matter (DOM) by microorganisms. High resolution methods were applied to elucidate the DOM molecular composition and the microbial community structure, and the data was analyzed via multivariate statistics to provide novel insights into the relationship between the two key players. Main findings include 1. DOM in high latitude environments is rapidly transformed due to microbial activity, 2. the North Sea is highly impacted by the input of terrigenous DOM and the molecular DOM composition can be connected with the composition of the total and the active microbial community, and 3. refractory deep ocean-like DOM may be biologically produced by microorganisms in the laboratory within several weeks. engl.
Download or read book A Spatial Deconvolution of Molecular Signals in Oceanic Dissolved Organic Matter written by Travis Blake Meador and published by . This book was released on 2008 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis provides chemical characterization data for ultrafiltered dissolved organic matter (UDOM) isolated from multiple depths in the western equatorial Atlantic and subtropical Pacific Oceans, the Southern California Bight, and the Benguela upwelling regime (n = 80). Multiple chemical characterization measurements were performed on this large set of UDOM samples including elemental analysis, stable C and N isotopic composition ([delta]13C and [delta]15N), radiocarbon analysis, 1H-NMR spectroscopy, monosaccharide composition, and novel application of several protein quantification methods. Most samples were collected as part of an extensive field program aimed at describing the biocomplexity of ocean ecosystems. Therefore, complimentary data collected as part of this field program enabled a uniquely comprehensive assessment of relationships between physical-biological variables and DOM composition. Nitrogen (N) isotope dynamics are a common theme in all chapters and these data were used to study the flow of N within the microbial loop of the upper ocean and through the DOM reservoir.[[delta]15N-UDOM showed remarkable homogeneity over this vast spatial array when compared to the [delta]15N dynamics of the short-lived particulate N reservoir suggesting that dissolved organic nitrogen (DON) contributed by contemporary processes does not accumulate in the upper ocean. Further isotopic analyses of planktonic nucleic acids (NA) and the protein component of DON provided evidence for the rapid recycling of DON contributed by diazotrophs in these regions characterized by extremely low concentrations of inorganic N.N isotope fractionation effects associated with the biosynthesis of NA by marine phytoplankton were also examined in one chapter to establish the validity of using [delta]15N-NA of size-fractionated field assemblages to identify biological sinks for dissolved organic nitrogen (DON). Basin-wide comparisons of chemical composition data revealed significant differences in [delta]15N0UDON between the subtropical N. Atlantic (avg."s.d. = 4.1"0.6%0) and Pacific Oceans (5.3"0.8%0 and 15.0"1.4, p
Download or read book Microbial Production and Consumption of Marine Dissolved Organic Matter written by Jamie William Becker and published by . This book was released on 2013 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine phytoplankton are the principal producers of oceanic dissolved organic matter (DOM), the organic substrate responsible for secondary production by heterotrophic microbes in the sea. Despite the importance of DOM in marine food webs, details regarding how marine microbes cycle DOM are limited, and few definitive connections have been made between specific producers and consumers. Consumption is thought to depend on the source of the DOM as well as the identity of the consumer; however, it remains unclear how phytoplankton diversity and DOM composition are related, and the metabolic pathways involved in the turnover of DOM by different microbial taxa are largely unknown. The motivation for this thesis is to examine the role of microbial diversity in determining the composition, lability, and physiological consumption of marine DOM. The chemical composition of DOM produced by marine phytoplankton was investigated at the molecular level using mass spectrometry. Results demonstrate that individual phytoplankton strains release a unique suite of organic compounds. Connections between DOM composition and the phylogenetic identity of the producing organism were identified on multiple levels, revealing a direct relationship between phytoplankton diversity and DOM composition. Phytoplankton-derived DOM was also employed in growth assays with oligotrophic bacterioplankton strains to examine effects on heterotrophic growth dynamics. Reproducible responses ranged from suppressed to enhanced growth rates and cell yields, and depended both on the identity of the heterotroph and the source of the DOM. Novel relationships between specific bacterioplankton types and DOM from known biological sources were found, and targets for additional studies on reactive DOM components were identified. The physiology of DOM consumption by a marine Oceanospirillales strain was studied using a combined transcriptomic and untargeted metabolomic approach. The transcriptional response of this bacterium to Prochlorococcus-derived DOM revealed an increase in anabolic processes related to metabolism of carboxylic acids and glucosides, increased gene expression related to proteorhodopsin-based phototrophy, and decreased gene expression related to motility. Putative identification of compounds present in Prochlorococcus-derived DOM supported these responses. Collectively, these findings highlight the potential for linking detailed chemical analyses of labile DOM from a known biological source with bacterioplankton diversity and physiology.
Download or read book The Role of Terrestrial Organic Matter in the Lower Aquatic Food Web written by Jennifer Lynne Harfmann and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Terrestrial organic matter (tOM) is a major contributor to global biogeochemical cycling, fundamentally linking pools of terrestrial and marine carbon, and can also influence and be influenced by local biogeochemical processes mediated by the lower aquatic food web. The goal of this research was to assess the interactions between tOM quality and primary consumers (bacteria and zooplankton) in order to constrain places and times where tOM source inputs are most influential in supporting the aquatic food web. Specific objectives included (1) evaluating compositional changes in vascular plant leachate dissolved organic matter (DOM) mediated by microbial and photochemical-microbial degradation, (2) constraining and calibrating vascular plant source biomarkers through microbial incubations, and (3) assessing zooplankton consumption of vascular plant particulates and survival across a variety of particulate organic matter (POM) diets. Microbial and photochemical-microbial incubations of four vascular plant leachates (ponderosa pine, blue oak, mixed annual grasses, mixed tule/cattail) indicated that despite initial variability in vascular plant source composition, degradation of dissolved tOM led to both optical and chemical convergence. Loss of source characteristics suggests that dissolved tOM source endmembers are much less significant than might be expected in dictating downstream microbial bioavailability, and compositional convergence may serve to buffer aquatic ecosystems when riparian landscapes (and subsequent terrestrial inputs) change Constraining dissolved tOM source endmembers is crucial in quantifying pools and fluxes that dictate global biogeochemical budgets. Using endmembers derived from our microbial degradation experiments, we estimated that vascular plant material contributions to Arctic, temperate, and tropical riverine DOM averaged 16%, 48%, and 73%, respectively, supporting that, particularly in low DOM systems, a significant proportion of the DOM pool is unaccounted for by vascular plant biomarkers. Constraining non-vascular (e.g. microbial) endmembers proved more challenging and highlighted that microbial processing of tOM may be characterized by small molecular changes in functional groups rather than remineralization and production of new microbial compounds. While microbial utilization of dissolved tOM is a widely accepted phenomenon, incorporation of particulate tOM into the aquatic food web is less certain. A novel DNA metagenomic sequencing technique was developed to track zooplankton consumption of particulate tOM relative to algal resources. Zooplankton feeding experiments indicated that copepods not only consume particulate tOM (assessed chemically and genetically via gut content) but do so deliberately and confer benefits from it (i.e. increased survival) when other food resources such as phytoplankton are limited. Particulate tOM can therefore act as a lifeline for zooplankton in tidal wetlands or other aquatic systems with high amounts of tOM and low phytoplankton primary productivity.
Download or read book Molecular Composition of Dissolved Organic Matter Controls Metal Speciation and Microbial Uptake written by Vaughn Mangal and published by . This book was released on 2019 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aquatic contaminant mobility and biological availability is strongly governed by the complexation oforganic and inorganic ligands. Dissolved organic matter (DOM) is a complex, heterogeneous mixture of organic acids, amino acids, lipids, carbohydrates and polyphenols that varyin composition and cancomplex to dissolved metalsthereby altering their fate in aquatic systems. The research conductedin this doctoral dissertation addresses1) how DOM compositiondiffers betweenphytoplanktontaxa and 2) how DOM composition affectsmetal speciation and its subsequent microbial bioavailabilityin laboratory and field conditions.To accomplish this, a series of analytical methods were developed and applied toquantifythiols, sulphur containing DOM moieties,and the molecular composition of DOM.The works presented in this thesisrepresentsone of the first comprehensiveand multipronged analyses of the impact of phytoplankton metabolite exudates on microbial metalbioavailability.This dissertationdemonstratedthe analytical versatility of high-resolution mass spectrometry as a tool for compound specific information, as well as having the capabilities to obtain speciation information of organometallic complexes. Thework presentedin this PhDstrengthens the understanding compositional differences of both autochthonous and allochthonous DOM andtheir effects on metal biogeochemistry. Keywords:Dissolved organic matter, Mercury, Cadmium, High Resolution Mass Spectrometry, Phytoplankton, Churchill, Metal Bioavailability.
Download or read book Extracellular Enzymes in Aquatic Environments Exploring the Link Between Genomic Potential and Biogeochemical Consequences written by Maria Montserrat Sala and published by Frontiers Media SA. This book was released on 2019-09-19 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial extracellular enzymes are fundamental to the cycling of elements in aquatic systems. The regulation of these enzymatic reactions in oceans, lakes and streams is under complex multiple control by environmental factors and the metabolic capacities of different taxa and communities. While the environmental control of enzyme-mediated processes has been investigated for over 100 years, in recent years tremendous progress in techniques to characterize the metabolic potential of microbial communities (“omics” techniques) has been made, such as high-throughput sequencing and new analytical algorithms. This book explores the controls, activities, and biogeochemical consequences of enzymes in aquatic environments. It brings together experimental studies and fieldwork conducted with natural microbial communities in marine and freshwater ecosystems as well as physiological, biochemical and molecular studies on microbial communities in these environments, or species isolated from them. Additionally, the book contributes to the ongoing debate on the impact of anthropogenic climate change and pollution on microbes, extracellular enzymes and substrate turnover.
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 Hydrobiogeochemistry of major asian rivers written by Shafi Mohammad Tareq and published by Frontiers Media SA. This book was released on 2023-06-30 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
