The Role of Organic Matter in Structuring Microbial Communities PDF Download
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Author: L. Kaplan
Publisher: IWA Publishing
ISBN: 1843398974
Category : Science
Languages : en
Pages : 116
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Book Description
Natural organic matter is important to the quality of drinking water. It constitutes precursors for disinfectant by-product formation and supports regrowth of bacteria. The drinking water industry is involved in work designed to improve biological treatment of water, control bacterial regrowth in distribution systems, and measure biodegradable NOM concentrations. These efforts would benefit from a knowledge of NOM composition and structure and the composition of microbial communities that colonize biological filters and distribution systems. In this project the researchers addressed four major goals: (1) to determine the structure and composition of natural organic matter (NOM), (2) to describe the structure of heterotrophic bacterial communities supported by raw and treated source water, (3) to measure the responses of heterotrophic bacterial communities to seasonally driven variations in NOM and temperature, and (4) to determine whether bioreactor systems can serve as small-scale models for the development and refinement of drinking water treatment processes. The five source waters selected for this project included a broad range of physiographic provinces, vegetation zones, and NOM concentrations. The research team analyzed NOM and microbial communities from an analytical hierarchy involving assessment of concentration, composition, and structure. Concentrations of NOM and BOM were estimated from dissolved organic carbon (DOC) and biodegradable DOC concentrations. NOM composition was assessed from analyses of carbohydrates with ion chromatography with pulsed amperometric detection, humic substances with XAD-8 resin, and functional groups with NMR. Molecular structure was determined from tetramethylammonium hydroxide thermochemolysis (TMAH) GC/MS. Microbial community composition was assessed from comparative ribosomal ribonucleic acid (RNA) sequencing, specifically, terminal restriction fragment length polymorphisms (t-RFLP), to provide an overview of microbial population structure and detect population shifts at the level of species. NOM Composition NOM and BOM concentrations showed extensive temporal variation in all of the source waters, but a general pattern of concentration ranges was discernable, indicating that each watershed has a particular concentration signal. Compositional studies revealed that humic substances and complex carbohydrates are components of both NOM and BOM. Structural and compositional studies identified unique NOM signatures for the different source waters, with some classes of molecules observed only in specific source waters. The BOM pool included humic substances and lignin, sources generally presumed to be relatively resistant to biodegradation. Additional novel insights included the quantitative contribution of aromatic molecules to the BOM pool and the potential for bacterial demethylation of lignin. Bacterial Communities The communities of microorganisms that developed in bioreactors that were fed water from different watersheds were unique. NOM influenced the genetic composition of resulting microbial communities, and seasonal shifts were observed for watersheds possessing strong seasonal temperature signals. Thus, temperature and organic matter quantity and quality probably influenced parameters important to the biological treatment of drinking water. A comparison of bioreactor metabolism with rapid sand filters showed some overlap, suggesting the bioreactors may indicate the ultimate potential of rapid sand filters for BOM processing. The researchers recommend the following: Bioreactors designed to monitor a BOM source should ideally be inoculated, colonized, and maintained by that source; at a minimum, acclimation to the source over several months is needed. Seasonal changes in the microbial community colonizing a biologically active filter may diminish filter performance and require an acclimation period to restore performance. Molecular-based methods for both microbial and chemical analyses of drinking water and treatment processes should be targeted for continued development and implementation within the drinking water industry. Originally published by AwwaRF for its subscribers in 2004.
Author: L. Kaplan
Publisher: IWA Publishing
ISBN: 1843398974
Category : Science
Languages : en
Pages : 116
Get Book Here
Book Description
Natural organic matter is important to the quality of drinking water. It constitutes precursors for disinfectant by-product formation and supports regrowth of bacteria. The drinking water industry is involved in work designed to improve biological treatment of water, control bacterial regrowth in distribution systems, and measure biodegradable NOM concentrations. These efforts would benefit from a knowledge of NOM composition and structure and the composition of microbial communities that colonize biological filters and distribution systems. In this project the researchers addressed four major goals: (1) to determine the structure and composition of natural organic matter (NOM), (2) to describe the structure of heterotrophic bacterial communities supported by raw and treated source water, (3) to measure the responses of heterotrophic bacterial communities to seasonally driven variations in NOM and temperature, and (4) to determine whether bioreactor systems can serve as small-scale models for the development and refinement of drinking water treatment processes. The five source waters selected for this project included a broad range of physiographic provinces, vegetation zones, and NOM concentrations. The research team analyzed NOM and microbial communities from an analytical hierarchy involving assessment of concentration, composition, and structure. Concentrations of NOM and BOM were estimated from dissolved organic carbon (DOC) and biodegradable DOC concentrations. NOM composition was assessed from analyses of carbohydrates with ion chromatography with pulsed amperometric detection, humic substances with XAD-8 resin, and functional groups with NMR. Molecular structure was determined from tetramethylammonium hydroxide thermochemolysis (TMAH) GC/MS. Microbial community composition was assessed from comparative ribosomal ribonucleic acid (RNA) sequencing, specifically, terminal restriction fragment length polymorphisms (t-RFLP), to provide an overview of microbial population structure and detect population shifts at the level of species. NOM Composition NOM and BOM concentrations showed extensive temporal variation in all of the source waters, but a general pattern of concentration ranges was discernable, indicating that each watershed has a particular concentration signal. Compositional studies revealed that humic substances and complex carbohydrates are components of both NOM and BOM. Structural and compositional studies identified unique NOM signatures for the different source waters, with some classes of molecules observed only in specific source waters. The BOM pool included humic substances and lignin, sources generally presumed to be relatively resistant to biodegradation. Additional novel insights included the quantitative contribution of aromatic molecules to the BOM pool and the potential for bacterial demethylation of lignin. Bacterial Communities The communities of microorganisms that developed in bioreactors that were fed water from different watersheds were unique. NOM influenced the genetic composition of resulting microbial communities, and seasonal shifts were observed for watersheds possessing strong seasonal temperature signals. Thus, temperature and organic matter quantity and quality probably influenced parameters important to the biological treatment of drinking water. A comparison of bioreactor metabolism with rapid sand filters showed some overlap, suggesting the bioreactors may indicate the ultimate potential of rapid sand filters for BOM processing. The researchers recommend the following: Bioreactors designed to monitor a BOM source should ideally be inoculated, colonized, and maintained by that source; at a minimum, acclimation to the source over several months is needed. Seasonal changes in the microbial community colonizing a biologically active filter may diminish filter performance and require an acclimation period to restore performance. Molecular-based methods for both microbial and chemical analyses of drinking water and treatment processes should be targeted for continued development and implementation within the drinking water industry. Originally published by AwwaRF for its subscribers in 2004.
Author: Rachel Elizabeth Sipler
Publisher:
ISBN:
Category : Aquatic ecology
Languages : en
Pages : 179
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Book Description
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.
Author: Johanna Sjöstedt
Publisher: Frontiers Media SA
ISBN: 2889711021
Category : Science
Languages : en
Pages : 255
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Book Description
Author: Hila Elifantz
Publisher:
ISBN: 9789570516012
Category :
Languages : en
Pages : 127
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Book Description
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.
Author: Dennis A. Hansell
Publisher: Academic Press
ISBN: 0124071538
Category : Science
Languages : en
Pages : 712
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Book Description
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
Author: Josep M. Gasol
Publisher: John Wiley & Sons
ISBN: 1119107202
Category : Science
Languages : en
Pages : 663
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Book Description
The newly revised and updated third edition of the bestselling book on microbial ecology in the oceans The third edition of Microbial Ecology of the Oceans features new topics, as well as different approaches to subjects dealt with in previous editions. The book starts out with a general introduction to the changes in the field, as well as looking at the prospects for the coming years. Chapters cover ecology, diversity, and function of microbes, and of microbial genes in the ocean. The biology and ecology of some model organisms, and how we can model the whole of the marine microbes, are dealt with, and some of the trophic roles that have changed in the last years are discussed. Finally, the role of microbes in the oceanic P cycle are presented. Microbial Ecology of the Oceans, Third Edition offers chapters on The Evolution of Microbial Ecology of the Ocean; Marine Microbial Diversity as Seen by High Throughput Sequencing; Ecological Significance of Microbial Trophic Mixing in the Oligotrophic Ocean; Metatranscritomics and Metaproteomics; Advances in Microbial Ecology from Model Marine Bacteria; Marine Microbes and Nonliving Organic Matter; Microbial Ecology and Biogeochemistry of Oxygen-Deficient Water Columns; The Ocean’s Microscale; Ecological Genomics of Marine Viruses; Microbial Physiological Ecology of The Marine Phosphorus Cycle; Phytoplankton Functional Types; and more. A new and updated edition of a key book in aquatic microbial ecology Includes widely used methodological approaches Fully describes the structure of the microbial ecosystem, discussing in particular the sources of carbon for microbial growth Offers theoretical interpretations of subtropical plankton biogeography Microbial Ecology of the Oceans is an ideal text for advanced undergraduates, beginning graduate students, and colleagues from other fields wishing to learn about microbes and the processes they mediate in marine systems.
Author: Rattan Lal
Publisher: Springer Science & Business Media
ISBN: 9400764553
Category : Technology & Engineering
Languages : en
Pages : 467
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Book Description
Ecological functions and human wellbeing depend on ecosystem services. Among the ecosystem services are provisional (food, feed, fuel, fiber), regulating (carbon sequestration, waste recycling, water cleansing), cultural (aesthetic, recreational, spiritual), and supporting services (soil formation, photosynthesis, nutrient cycling). Many relationships of various degree exist among ecosystem services. Thus, land use and soil management to enhance biospheric carbon sinks for carbon sequestration requires a comprehensive understanding on the effects on ecosystem services. Payments for ecosystem services including carbon pricing must address the relationship between carbon sequestration and ecosystem services to minimize risks of overshoot, and promote sustainable use of land-based carbon sinks for human wellbeing.
Author: Moumita Moitra
Publisher:
ISBN:
Category : Bacteria
Languages : en
Pages : 283
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Book Description
Dissolved organic carbon (DOC) is the dominant form of organic matter in aquatic ecosystems and bacteria play a key role in its mobilization to higher trophic levels. The DOC pool is often divided into broad classes such as labile or recalcitrant, based on its ease of uptake by bacteria; or as autochthonous and allochthonous, based on its production within or outside the ecosystem. In this dissertation, I examined the relationship between the composition of the DOC pool and bacterial community structure and function. The three research chapters address this relationship in different freshwater ecosystems. In the first research chapter, the effect of presence or absence of Microcystis, a dominant primary producer in the western basin of Lake Erie as well as an autochthonous DOC source, on bacterial community structure and heterotrophic productivity was studied. This study revealed that bacterial responses were independent of the presence of the dominant primary producer. In second research chapter, the effect of compositional diversity of DOC within labile and recalcitrant categories, on stream bacterial community structure and denitrification rates was investigated. Use of different compounds within each category, administered individually and in mixtures, contributed to the heterogeneity. Results of this study suggest molecular heterogeneity of DOC can lead to differences in bacterial structure and denitrification potential. In my final research chapter, bacterial responses to differences in proportion of autochthonous and allochthonous DOC between a river and reservoir ecosystem were compared. The findings of this study demonstrated that, rather than the proportion of the two DOC sources, each source, considered individually, played a more important role in determining bacterial response. Regardless of the study, in all cases bacterial community structure was not linked to function, emphasizing the requirement to study both. The results indicate that differences in DOC quality, rather than the quantity, may play a greater role in determining bacterial responses and that structure and function can be decoupled.
Author: Dennis A. Hansell
Publisher: Elsevier
ISBN: 0443138591
Category : Science
Languages : en
Pages : 870
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Book Description
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
Author: Philips Olugbemiga Akinwole
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 168
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Book Description
Sedimentary microbial communities play a critical ecological role in lotic ecosystems and are responsible for numerous biogeochemical transformations, including dissolved organic matter (DOM) uptake, degradation, and mineralization. The goals of this study were to elucidate the benthic microbes responsible for utilization of humic DOM in streams and to assess overall variability in microbial biomass and community structure over time and across multiple spatial scales in stream networks, as DOM quality and quantity will likely change with stream order. In Chapter 2, multiple spatial patterns of microbial biomass and community structure were examined in stream sediments from two watersheds; the Neversink River watershed (NY; 1st, 3rd and 5th order streams sampled) and the White Clay Creek watershed (PA; 1st through 3rd order streams sampled). Microbial biomass and community structure were estimated by phospholipid phosphate and phospholipid fatty acids (PLFA) analyses. Multivariate analysis showed that sedimentary C:N ratios, percent carbon, sediment surface area and percent water content explained 68% of the variations in total microbial biomass. Overall, the magnitude of within stream variation in microbial biomass was small compared to the variability noted among streams and between watersheds. Principal component analysis (PCA) of PLFA profiles showed that microbial community structure displayed a distinct watershed-level biogeography, as well as variation along a stream order gradient. Chapter 3 demonstrated that benthic microbial biomass was seasonally dynamic and significantly correlated to a combination of high and low flood pulse counts, variability in daily flow and DOC concentration in the White Clay Creek. Additionally, the seasonal pattern of variation observed in microbial community structure was as a result of shift between the ratios of prokaryotic to eukaryotic component of the community. This shift was significantly correlated with seasonal changes in median daily flow, high and low flood pulse counts, DOC concentrations and water temperature. Compound-specific 13C analysis of PLFA showed that both bacterial and microeukaryotic stable carbon isotope ratios were heaviest in the spring and lightest in autumn or winter. Bacterial lipids were isotopically depleted on average by 2 - 5 / relative to δ13C of total organic carbon suggesting bacterial consumption of allochthonous organic matter, and enriched relative to δ13C algae-derived carbon source. In Chapter 4, heterotrophic microbes that metabolize humic DOM in a third-order stream were identified through trace-additions of 13C-labeled tree tissue leachate (13C-DOC) into stream sediment mesocosms. Microbial community structure was assessed using PLFA biomarkers, and metabolically active members were identified through 13C-PLFA analysis (PLFA-SIP). Comparison by PCA of the microbial communities in stream sediments and stream sediments incubated in both the presence and absence of 13C-DOC showed our mesocosm-based experimental design as sufficiently robust to investigate the utilization of 13C-DOC by sediment microbial communities. After 48 hours of incubation, PLFA-SIP identified heterotrophic α, β, and γ- proteobacteria and facultative anaerobic bacteria as the organisms primarily responsible for humic DOC consumption in streams and heterotrophic microeucaryotes as their predators. The evidence presented in this study shows a complex relationship between microbial community structure, environmental heterogeneity and utilization of humic DOC, indicating that humic DOC quality and quantity along with other hydro-ecological variables should be considered among the important factors that structure benthic microbial communities in lotic ecosystems.
