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Microbial Community Composition And Organic Carbon Cycling In Permanently Cold Marine Sediments Svalbard
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Book Synopsis Microbial Community Composition and Organic Carbon Cycling in Permanently Cold Marine Sediments (Svalbard) by : Sabrina Neill Powell
Download or read book Microbial Community Composition and Organic Carbon Cycling in Permanently Cold Marine Sediments (Svalbard) written by Sabrina Neill Powell and published by . This book was released on 2002 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Acquisition, Degradation, and Cycling of Organic Matter Within Sea-ice Brines by Bacteria and Their Viruses by : Gordon Maxwell Showalter
Download or read book Acquisition, Degradation, and Cycling of Organic Matter Within Sea-ice Brines by Bacteria and Their Viruses written by Gordon Maxwell Showalter and published by . This book was released on 2020 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine dissolved organic carbon (DOC) is a major component of the global carbon pool, and thus can have significant effects on global carbon cycling. Within the oceans, DOC is largely regulated by microbial communities, which can serve as both a source and sink of organic carbon. Microbial controls on DOC cycling within sea ice are especially relevant to global processes, as sea ice can act as an inhibitor of exchange between the ocean and the atmosphere while also affecting carbon export to the deep sea. However, how sea-ice communities influence DOC cycling, especially in very cold conditions of winter sea ice, is poorly understood. This dissertation explores how bacterial communities, which dominate winter sea ice, may influence DOC cycling. Chapter 1 presents an introduction of sea-ice microbial communities in the low-temperature, high salinity conditions which characterize sea-ice brines. How bacteria within brines swim in response to temperature, salinity, and chemical gradients in sea ice is presented in Chapter 2, which demonstrates a low-temperature record for directed bacterial swimming and suggests explanations for how bacteria position themselves within brines to access DOC. However, most DOC within the marine environment is too large for bacterial uptake, necessitating degradation by enzymes. Chapter 3 demonstrates bacterial extracellular enzyme activity both in a laboratory setting and in situ, showing growth-dependent enzyme activity down to -8°C and up to 142 ppt salts and across a freeze-thaw cycle within sea ice and sea-surface microlayer samples. Finally, Chapter 4 presents a model of bacterially and virally mediated DOC cycling. This model uses simple differential equations, explained further in Appendix 1, to probe the potential existence of a viral shunt within sea-ice brines by demonstrating the role of bacteriophage in population dynamics of a theoretical brine, suggesting low viral production, high host-specificity, and virally-driven DOC cycling may be common within this environment. The results of this dissertation have implications for the understanding of DOC within polar seas and demonstrate the potential for active DOC cycling mediated by bacteria and their viruses within winter sea ice, which serves as an analog for very cold ice elsewhere.
Book Synopsis The Organic Carbon Cycle in the Arctic Ocean by : Rüdiger Stein
Download or read book The Organic Carbon Cycle in the Arctic Ocean written by Rüdiger Stein and published by Springer Science & Business Media. This book was released on 2011-06-27 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: The flux, preservation, and accumulation of organic carbon in marine systems are controlled by various mechanisms including primary p- duction of the surface water, supply of terrigenous organic matter from the surrounding continents, biogeochemical processes in the water column and at the seafloor, and sedimentation rate. For the world's oceans, phytoplankton productivity is by far the largest organic carbon 9 source, estimated to be about 30 to 50 Gt (10 tonnes) per year (Berger et al. 1989; Hedges and Keil 1995). By comparison, rivers contribute -1 about 0. 15 to 0. 23 Gt y of particulate organi.
Book Synopsis Microbial Communities in Coastal Sediments by : Salom Gnana Thanga Vincent
Download or read book Microbial Communities in Coastal Sediments written by Salom Gnana Thanga Vincent and published by Elsevier. This book was released on 2021-06-02 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: A concise reference on the structural composition and function of microbial communities in coastal environments, especially in relation to natural and anthropogenic impacts. Microbial Communities in Coastal Sediments presents twenty years of coastal microbiology research, grounding it as a vital development in the field of microbial ecology. It is the first book to focus exclusively on the complex microbial ecology and its function in rest of the marine environment. The book outlines the structure, function, and assessment of microbial communities in marine sediments while exploring practical methods of assessment. It is an invaluable resource to aquatic microbiologists, marine ecologists, marine microbiologists, aquatic researchers, and graduate students in this field. Microbial Communities in Coastal Sediments begins with an examination of nutrient sources in the coastal context with a focus on organic matter inputs. The quantity and quality of organic matter in coastal sediments and their impacts on the composition and formation of microbial communities is discussed. The book explores the consequences of anthropogenic changes and human activity on microbial ecology and nutrient cycling. Sections on nutrient availability, green house gas production and biodegradation of persistent organic pollutants provide essential details. Molecular research techniques and methods for assessing microbial community structure and function in coastal sediments are also covered. - Explores the interplay of physicochemical and biological features of coastal ecosystems on microbial community composition to provide a template of comparison for field research - Includes unique figures, schematic diagrams and photographs related to microbial processes of coastal ecosystem to clearly represent different aspects of microbial structure and functions - Provides analytical methods and detailed molecular techniques for qualitative and quantitative analyses of microbial community structure
Book Synopsis Microbial Ecology of the Oceans by : Josep M. Gasol
Download or read book Microbial Ecology of the Oceans written by Josep M. Gasol and published by John Wiley & Sons. This book was released on 2018-01-31 with total page 567 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Microbial Responses to Environmental Changes by : Jürg B. Logue
Download or read book Microbial Responses to Environmental Changes written by Jürg B. Logue and published by Frontiers Media SA. This book was released on 2016-01-20 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in next generation sequencing technologies, omics, and bioinformatics are revealing a tremendous and unsuspected diversity of microbes, both at a compositional and functional level. Moreover, the expansion of ecological concepts into microbial ecology has greatly advanced our comprehension of the role microbes play in the functioning of ecosystems across a wide range of biomes. Super-imposed on this new information about microbes, their functions and how they are organized, environmental gradients are changing rapidly, largely driven by direct and indirect human activities. In the context of global change, understanding the mechanisms that shape microbial communities is pivotal to predict microbial responses to novel selective forces and their implications at the local as well as global scale. One of the main features of microbial communities is their ability to react to changes in the environment. Thus, many studies have reported changes in the performance and composition of communities along environmental gradients. However, the mechanisms underlying these responses remain unclear. It is assumed that the response of microbes to changes in the environment is mediated by a complex combination of shifts in the physiological properties, single-cell activities, or composition of communities: it may occur by means of physiological adjustments of the taxa present in a community or selecting towards more tolerant/better adapted phylotypes. Knowing whether certain factors trigger one, many, or all mechanisms would greatly increase confidence in predictions of future microbial composition and processes. This Research Topic brings together studies that applied the latest molecular techniques for studying microbial composition and functioning and integrated ecological, biogeochemical and/or modeling approaches to provide a comprehensive and mechanistic perspective of the responses of micro-organisms to environmental changes. This Research Topic presents new findings on environmental parameters influencing microbial communities, the type and magnitude of response and differences in the response among microbial groups, and which collectively deepen our current understanding and knowledge of the underlying mechanisms of microbial structural and functional responses to environmental changes and gradients in both aquatic and terrestrial ecosystems. The body of work has, furthermore, identified many challenges and questions that yet remain to be addressed and new perspectives to follow up on.
Book Synopsis Microbiology of wetlands by : Paul Bodelier
Download or read book Microbiology of wetlands written by Paul Bodelier and published by Frontiers E-books. This book was released on 2013-07-08 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: Watersaturated soil and sediment ecosystems (i.e. wetlands) are ecologically as well as economically important systems due to their high productivity, their nutrient (re)cycling capacities and their prominent contribution to global greenhouse gas emissions. Being on the transition between terrestrial and – aquatic ecosystems, wetlands are buffers for terrestrial run off thereby preventing eutrophication of inland as well as coastal waters. The close proximity of oxic-anoxic conditions, often created by wetland plant roots, facilitates the simultaneous activity of aerobic as well as anaerobic microbial communities. Input of nutrients and fast recycling due to active aerobes and anaerobes makes these systems highly productive and therefore attractive for humans as well as many other organisms. Wetlands globally are under high pressure due to anthropogenic activities as well as climate change. Changes of land-use as well as altered hydrology due to climate change will lead to disturbance and loss of these habitats. However, the diversity and functioning of microbial communities in wetlands systems in highly underexplored in comparison to soils and aquatic ecosystems. Given the importance of wetlands and their immediate threats combined with the lack of knowledge on the microbiology of these systems is the basis for this special issue, focusing on the current microbiological knowledge and gaps therein to be assessed in future wetland research. Papers (research papers, reviews, perspectives, opinion papers) are welcomed that focus on all aspects that regulate the functioning and community composition of microbes (i.e. bacteria, archaea, protozoa, fungi) in wetland ecosystems (peat, coastal as well as freshwater marshes, flood plains, rice paddies, littoral zones of lakes etc) from all geographic regions. Welcomed topics are physiology, ecology, functioning, biodiversity, biogeography of microbes involved in nutrient cycling (C, N, P, Fe, Mn), green house gas emissions as well as plant-microbe interactions. These studies can be multidisciplinary and cover topics from the molecular to the community level.
Book Synopsis Carbon Cycling in Arctic Marine Ecosystems: Case Study Young Sound by : Ronnie N. Glud
Download or read book Carbon Cycling in Arctic Marine Ecosystems: Case Study Young Sound written by Ronnie N. Glud and published by Museum Tusculanum Press. This book was released on 2007 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Carbon Cycle in the Russian Arctic Seas by : Alexander Vetrov
Download or read book Carbon Cycle in the Russian Arctic Seas written by Alexander Vetrov and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study analyzes carbon-cycle conditions controlling the state of the Arctic ecosystem and their seasonal variations. Territory covered includes the Barents, White, Kara, Laptev, East-Siberian and Chukchi Seas, considering inter-correlations between sources of organic carbon, their fluxes, recycling and burial in bottom sediments. All biological communities (phythoplankton, macrophythobenthos, microphythobentos, bacterioplankton, zooplankton and zoobenthos) are taken into account regarding their participation in the carbon cycle.
Book Synopsis Psychrophiles: From Biodiversity to Biotechnology by : Rosa Margesin
Download or read book Psychrophiles: From Biodiversity to Biotechnology written by Rosa Margesin and published by Springer. This book was released on 2017-06-22 with total page 685 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cold adaptation includes a complex range of structural and functional adaptations at the level of all cellular constituents, and these adaptations render cold-adapted organisms particularly useful for biotechnological applications. This book presents the most recent knowledge of (i) boundary conditions for microbial life in the cold, (ii) microbial diversity in various cold ecosystems, (iii) molecular cold adaptation mechanisms and (iv) the resulting biotechnological perspectives.
Book Synopsis Applied and Environmental Microbiology by :
Download or read book Applied and Environmental Microbiology written by and published by . This book was released on 2000 with total page 998 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Benthic Carbon Cycling on the Antarctic Continental Shelf by : Marwa Baloza
Download or read book Benthic Carbon Cycling on the Antarctic Continental Shelf written by Marwa Baloza and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sedimentation of pelagic production makes continental shelf sediments important sites for organic matter (OM) remineralization and nutrient regeneration in the ocean. Consequently, shelf sediments play an important role in the bentho-pelagic coupling by providing essential nutrients for algal growth and maintaining the high primary production of shelf areas and the adjacent open ocean. In Antarctica, changes in sea ice cover have a major impact on surface primary production and the subsequent sinking of organic carbon to the seafloor. Recent observations indicate that global warming has led to substantial changes in sea ice cover, with a significant reduction of one million square kilometers in the annual maximum sea ice extent around Antarctica. These changes in sea ice conditions are expected to trigger significant changes in the pelagic ecosystem, with potentially profound effects on the benthic ecosystem. The imprint of climate-sensitive variables such as sea ice cover can be best studied in shelf sediments, where shallow water depths result in increased OM supply and tighter bentho-pelagic coupling. Therefore, a comprehensive understanding of the current carbon cycle on the Antarctic continental shelf is crucial for assessing the vulnerability of the ecosystem to climate change and for predicting the future trajectory of the carbon cycle in Antarctic waters. This thesis aims to quantify benthic carbon remineralization rates on the Antarctic continental shelf and the release of nutrients, particularly iron, that limit primary production in the Southern Ocean. In addition, the thesis aims to identify the main pathways of OM degradation and associated microbial communities, while contextualizing the above variables within the prevailing sea ice conditions. For this purpose, I first studied the geochemistry of shelf sediments along a gradient of sea ice cover on the eastern shelf of the Antarctic Peninsula (AP) (manuscript 1). The main focus was on carbon and iron fluxes within the sediment and between the water column and the sediment. The results were interpreted in the context of sea ice cover. An increase in carbon remineralization rates was observed as one moved from heavily ice-covered to moderately ice-covered stations where light availability and water column stratification increased. Conversely, the ice-free station displayed lower carbon remineralization rates and was subject to wind-driven mixing of the water column, which can deepen the mixed layer depth below the critical depth, resulting in reduced surface production. In summary, a positive correlation was found between moderate sea ice cover and increased carbon fluxes to the sediment, which followed an exponential increase. The study also revealed significant iron cycling in sediments with increased carbon remineralization, resulting in high dissolved iron fluxes. This finding highlights the importance of sediments underlying the moderate ice cover as a source of limiting nutrients for primary production in this region. A complementary study of benthic microbial communities along the AP transect was conducted using 16S ribosomal RNA (rRNA) gene sequencing (manuscript 2). The results indicate that sea ice cover and its effect on organic carbon fluxes are the main drivers of changes in benthic microbial communities. As sea ice cover decreases, the benthic microbial community shifts towards anaerobic communities of iron and sulfate reducers. These communities were more abundant at low ice cover stations than at high ice cover stations. Furthermore, an increase in the relative abundance of Sva1033, a Desulfuromonadia clade, with dissolved iron concentration at low ice cover stations suggests a putative role for Sva1033 in dissimilatory iron reduction in surface sediments. In addition to Sva1033, this study successfully identified other taxa that could potentially contribute to dissimilatory iron reduction or have syntrophic partnerships and/or common metabolic preferences with iron reducers. The focus was extended towards the southern shelf of the Weddell Sea, a region characterized by heavy sea ice cover (manuscript 3). Benthic oxygen uptake rates were measured at stations with different water depths and sediment compositions. Benthic measurements also revealed a dependence of carbon fluxes on sediment grain size and water depth. In general, diffusive oxygen uptake (DOU) rates on the southern Weddell Sea shelf were low. DOU showed a positive correlation with preserved total organic carbon (TOC) at stations with fine-grained sediments, whereas stations with typical of coarse-grained sediments showed a markedly different correlation of DOU with TOC. Common to all stations is that dissolved iron and manganese concentrations in pore water were found only at greater depths, suggesting very limited release of these nutrients back into the water column. The strong dependence of benthic carbon fluxes on sea ice cover and water depth was then combined to derive a simple empirical model, which was validated by all available DOU measurements reported in the literature for the Antarctic seasonal ice zone (manuscript 4). The model allows extrapolation and budgeting of benthic carbon remineralization for the entire seasonal ice zone (16 million km2), yielding a total of 46 Tg C yr-1. Notably, although the Antarctic continental shelf represents only 15% of the total area, it contributes a significant 71% (33 Tg C yr-1) of the total benthic carbon remineralization. Furthermore, the total organic carbon supply to the sediments and the carbon burial in the sediments were estimated to amount to 52 Tg C yr-1 and 6 Tg C yr-1, respectively. Overall, the thesis highlights the pivotal role of sea ice cover in controlling the benthic carbon and iron cycling on the Antarctic continental shelf. Through extensive data correlation and empirical modeling, the thesis has provided, for the first time, a quantitative framework for the relationship between sea ice cover and benthic carbon fluxes. It also emphasizes the substantial contribution of Antarctic shelf sediments to the marine carbon remineralization, allowing a better assessment of the carbon cycling and related CO2 sequestration across the Southern Ocean. Furthermore, it has improved our understanding of the main drivers of change in benthic microbial communities and, ultimately, nutrient fluxes across the sediment-water interface. These findings make a significant contribution to our understanding of the complex Antarctic ecosystem, which is necessary to assess the future trajectory of the Southern Ocean and its impact on the global carbon cycle.
Book Synopsis Carbon Cycling in the Glacial Ocean: Constraints on the Ocean’s Role in Global Change by : Rainer Zahn
Download or read book Carbon Cycling in the Glacial Ocean: Constraints on the Ocean’s Role in Global Change written by Rainer Zahn and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 579 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive progress report on the multi-disciplinary field of ocean and climate change research is given. It compiles introductory background papers and leading scientific results on the ocean-atmosphere carbon cycle with emphasis on the ocean's carbon inventory and the various components involved. The relationship between plankton productivity, carbon fixation, oceanic PCO2 and climate change is investigated from the viewpoint of long-term climatic change during the late Quaternary cycles of ice ages and warm ages. The various approaches range from micropaleontology over organic and trace element geochemistry to molecular isotope geochemistry.
Book Synopsis Temperature, Redox Conditions and Organic Matter Chemical Composition as Microbial Community Drivers in Marine Sediments by : Lorenzo Lagostina
Download or read book Temperature, Redox Conditions and Organic Matter Chemical Composition as Microbial Community Drivers in Marine Sediments written by Lorenzo Lagostina and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Extracellular Enzymes in Aquatic Environments: Exploring the Link Between Genomic Potential and Biogeochemical Consequences by : Maria Montserrat Sala
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.
Book Synopsis Marine Geochemistry by : Horst D. Schulz
Download or read book Marine Geochemistry written by Horst D. Schulz and published by Springer Science & Business Media. This book was released on 1999-12-17 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: A summary of the latest research in this field. The topics comprise the sedimentological examination and physical properties of the sedimentary solid phase, pore water and pore water constituents, organic matter as the driving force of most microbiological processes, biotic and abiotic redox reactions, carbonates and stable isotopes as proxies for paleoclimate reconstruction, metal enrichments in ferromanganese nodules and crusts as well as in hot vents and cold seeps on the seafloor. The current model conceptions lead to the development of different types of computer models, allowing the global mass exchanges between oceans and sediments to be balanced.
Download or read book Witness the Arctic written by and published by . This book was released on 2000 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
