Linkage Between Biogeochemical Properties and Microbial Activities in Lake Sediments

Linkage Between Biogeochemical Properties and Microbial Activities in Lake Sediments PDF Author: Isabela Claret Torres
Publisher:
ISBN:
Category :
Languages : en
Pages :

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And hypereutrophic Lake Apopka had the highest values for both [delta]13C and [delta]15N. Catabolic response profiles of a wide variety of C-substrates added to sediments indicated that different microbial communities are present in these sediments. The microbial community of hypereutrophic lake sediments had higher efficiency use of energy and higher catabolic diversity. This study highlighted the relationships between sediment biogeochemical properties and the microbial community, how they differ among lakes with different trophic states, and how the physico-chemical conditions of lakes affect sediment properties and microbemediated processes. Results suggest that although the microbial community is C/energy limited, C, coupled with N and P availability had a strong influence on microbial communities in these lakes sediments.

Linkage Between Biogeochemical Properties and Microbial Activities in Lake Sediments

Linkage Between Biogeochemical Properties and Microbial Activities in Lake Sediments PDF Author: Isabela Claret Torres
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
And hypereutrophic Lake Apopka had the highest values for both [delta]13C and [delta]15N. Catabolic response profiles of a wide variety of C-substrates added to sediments indicated that different microbial communities are present in these sediments. The microbial community of hypereutrophic lake sediments had higher efficiency use of energy and higher catabolic diversity. This study highlighted the relationships between sediment biogeochemical properties and the microbial community, how they differ among lakes with different trophic states, and how the physico-chemical conditions of lakes affect sediment properties and microbemediated processes. Results suggest that although the microbial community is C/energy limited, C, coupled with N and P availability had a strong influence on microbial communities in these lakes sediments.

Links Between Geological Processes, Microbial Activities & Evolution of Life

Links Between Geological Processes, Microbial Activities & Evolution of Life PDF Author: Yildirim Dilek
Publisher: Springer Science & Business Media
ISBN: 1402083068
Category : Science
Languages : en
Pages : 359

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Book Description
Microbial systems in extreme environments and in the deep biosphere may be analogous to potential life on other planetary bodies and hence may be used to investigate the possibilities of extraterrestrial life. This book examines the mode and nature of links between geological processes and microbial activities and their significance for the origin and evolution of life on the Earth and possibly on other planets. This is a truly interdisciplinary science with societal relevance.

Examining Anaerobic Microbial Communities that Direct the Fate of Terrestrial Carbon in Lake Sediments

Examining Anaerobic Microbial Communities that Direct the Fate of Terrestrial Carbon in Lake Sediments PDF Author: Kurt Yakimovich
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ISBN:
Category :
Languages : en
Pages :

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Book Description
Freshwater lake sediments play key roles in the cycling of carbon. This includes hosting microbial communities responsible for mineralizing large amounts of carbon into greenhouse gases-namely CO2 and CH4. Yet despite the important roles of sediment communities, their ecology and community structure linkages to biogeochemical cycling are not well known, and little data exists exploring how sediment microbial communities respond to different organic matter inputs. Here I start by reviewing previous literature on lake sediment microbial communities and the physicochemical factors affecting their composition and diversity. Next I report on data from two experiments, first an in-vitro lab study and then an in-situ field study, in which lake sediments were amended with different plant litters that could result from land use change and or succession in catchments. Microbial communities were examined with next generation amplicon sequencing. These data were linked to rates of CO2 and CH4 flux and dissolved organic matter (DOM) components present in pore water were examined as potential controls on community structure and function. I observed in-vitro that methanogen community composition and activity were affected by OM type, with macrophyte derived C enhancing microbial activity, whereas high concentrations of polyphenolic compounds from terrestrial tree litters inhibited methanogen activity. The polyphenols had an environmental filtering effect, selecting for different bacteria, fungi and methanogen communities. The in-situ experiments involved installing mesocosms with artificial sediments with variable amounts of deciduous and coniferous tree leaf litter. In these mesocosms we observed a link between methanogen community composition and decomposition rates, as measured with bulk CO2 and CH4 production and DOM humification. Decomposition rates were influenced by lake physicochemical factors, particularly the degree of photoexposure. With increased decomposition, specialist taxa of methanogens could thrive that conferred higher rates of methanogenesis. The work presented here demonstrates the adaptability of methanogen lake sediment communities as terminal decomposers under changing terrestrial OM subsidies.

Extracellular Enzymes in Aquatic Environments: Exploring the Link Between Genomic Potential and Biogeochemical Consequences

Extracellular Enzymes in Aquatic Environments: Exploring the Link Between Genomic Potential and Biogeochemical Consequences PDF Author: Maria Montserrat Sala
Publisher: Frontiers Media SA
ISBN: 2889630048
Category :
Languages : en
Pages : 159

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Book Description
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.

The Interactions between Sediments and Water

The Interactions between Sediments and Water PDF Author: Brian Kronvang
Publisher: Springer Science & Business Media
ISBN: 940173366X
Category : Technology & Engineering
Languages : en
Pages : 310

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Book Description
This book focuses on sediments as a pollutant in natural freshwater and marine habitats, and as a vector for the transfer of chemicals such as nutrients and contaminants. Sediment-water research is carried out all over the world within a variety of disciplines. The selected papers cover three main topics relating to assessment and/or restoration of disturbed watersheds, sediment-water linkages in terrestrial and aquatic environments and evaluation of sediment and ecological changes in marine and freshwater habitats. Innovative research in both developed and less developed countries is included. Both fundamental research, insight into applied research and system management are covered. The volume will also appeal to readers involved in sediment geochemistry and dynamics, aquatic habitats, water quality, aquatic ecology, river morphology, restoration techniques and catchment management.

Fundamentals of Soil Physics

Fundamentals of Soil Physics PDF Author: Daniel Hillel
Publisher: Academic Press
ISBN: 0080918700
Category : Science
Languages : en
Pages : 432

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Book Description
This book is not, in any case, in total defiance of the Wise Old Man's admonition, for it is not an entirely new book. Rather, it is an outgrowth of a previous treatise, written a decade ago, entitled "Soil and Water: Physical Principles and Processes." Though that book was well enough received at the time, the passage of the years has inevitably made it necessary to either revise and update the same book, or to supplant it with a fresh approach in the form of a new book which might incorporate still-pertient aspects of its predecessor without necessarily being limited to the older book's format or point of view.

Microbial Ecological and Biogeochemical Processes in the Soil-Vadose Zone-Groundwater Habitats

Microbial Ecological and Biogeochemical Processes in the Soil-Vadose Zone-Groundwater Habitats PDF Author: Zifang Chi
Publisher: Frontiers Media SA
ISBN: 2832540554
Category : Science
Languages : en
Pages : 134

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Book Description


Microbial Ecological and Biogeochemical Processes in the Soil-Vadose Zone-Groundwater Habitats, volume II

Microbial Ecological and Biogeochemical Processes in the Soil-Vadose Zone-Groundwater Habitats, volume II PDF Author: Zifang Chi
Publisher: Frontiers Media SA
ISBN: 2832554563
Category : Science
Languages : en
Pages : 169

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Book Description
Given the success of Volume I of this Research Topic, and how rapidly the subject area is evolving, we are pleased to announce the launch of Microbial Ecological and Biogeochemical Processes in the Soil-Vadose Zone-Groundwater Habitats, Volume II. You can check Volume I here: https://www.frontiersin.org/research-topics/37506/microbial-ecological-and-biogeochemical-processes-in-the-soil-vadose-zone-groundwater-habitats Microorganisms regulate biogeochemical cycles and serve various functions within the soil, vadose zone, and groundwater habitats. Microbial communities are sensitive to environmental changes and can respond to them rapidly. The composition and function of these microorganisms in different habitats can be influenced by biotic and abiotic factors, which affect biochemical processes and ecosystem functions. Therefore, to develop a healthy-stable-sustainable ecosystem, this research topic focuses on microbial ecological and biogeochemical processes in the soil-vadose zone-groundwater habitat.

Modelling Biogeochemical Cycles Across Scales

Modelling Biogeochemical Cycles Across Scales PDF Author: Igor Markelov
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Lakes are ecologically, economically, and culturally significant resources that are, at the same time, very fragile and sensitive to human disturbances. During the last decades, intensified urbanization and discharge of nutrients lead to the increase of lake eutrophication in many regions of the world. Moreover, biogeochemical cycles within the lakes are changing due to climate warming, which increases water temperature and affects physical and hydrological lake regimes. In this thesis, I investigate a vast scope of the natural and anthropogenic processes affecting the biogeochemical cycles in lakes at different scales. In particular, I examine the cascading effect of the climate, regional weather, human interventions, and microbial control on phosphorus dynamics in lakes. In Chapter 2, I demonstrate that on the lake scale, phosphorus cycle is driven by internal loading and iron recycling, while it is vulnerable to the reduction of ice cover. To achieve that, I expand the existing MyLake model by incorporating a sediment diagenesis module. Moreover, I develop the continuous reaction network that couples biogeochemical reactions taking place both in water column and sediment. In the modeling scenarios, I assess the importance of the sediment processes and the effects of the climatic and anthro- pogenic drivers on water quality in Lake Vansjø, Norway. I also highlight the importance of phosphorus accumulation within the lake that controls timing and magnitude of bio- geochemical lake responses to external forcing. This includes projected changes in the air temperature, absence of ice cover, and potential management practices. In Chapter 3, I contribute to the long-standing understanding that on the scales of microbial systems, the respiration reactions exert substantial control on biogeochemi- cal cycles by regulating the availability of the electron donors and acceptors, secondary minerals, adsorption sites, and alkalinity. Moreover, I develop a new conceptual model to simulate the preferential catabolic reaction pathways based on power produced in reactions. In contrast to common kinetic rate expressions, I demonstrate that new ther- modynamically based formulations can be applied to describe the microbial respiration of arbitrary large reaction networks. New approach substantially improves the robustness, transferability, and allows the generalization of the model-derived parameters. In Chapter 4, I show that on the regional scale, weather defines hydrodynamic flush rates and water circulation patterns, which, in turn, control the phosphorus transport in Lake Erie, Canada. Specifically, precipitation controls the release of phosphorus from the watershed in the spring, while wind governs the water circulation and transport of the phosphorus released from sediment in the central basin during summer. I also illustrate that climate and weather in the upper Laurentian Great Lakes regulate changes in the water level of Lake Erie. Overall, this thesis improves the fundamental understanding of the phosphorus cycle in lakes, which is being controlled by numerous biogeochemical and physical processes at various scales. In particular, I show that the climate has a cascading effect on the phosphorus cycle in lakes. First, climate controls regional precipitation, wind, and air temperature, which in turn control phosphorus supply from the watershed and basin- wide phosphorus transport. Second, being vulnerable to climate warming, the duration of ice cover impacts the phosphorus cycle through changes in light attenuation, water temperature, mixing regimes, and water column ventilation. Lastly, local environmental perturbations (e.g., pH, temperature, or redox state) define thermodynamic properties of the sediment, which control microbial metabolism and, therefore, the internal phosphorus loading. Finally, this thesis provides new open-source tools for reactive transport simula- tions in lakes as well as in saturated media. In addition to the coupled lake-sediment model developed in Chapter 3, I develop a computer program PorousMediaLab, which performs biogeochemical simulations in water-saturated media and described In Chapter 5. PorousMediaLab is the core component of the numerical investigations presented in the thesis. For example, PorousMediaLab is applied in Chapter 2 to design and test the initial reaction network, calculate fluxes at the sediment-water interface, and estimate re- action timescales. In Chapter 3, PorousMediaLab is used to simulate the reaction rates of batch and one-dimensional sediment column using a novel approach based on the thermo- dynamic switch function. In Chapter 4, PorousMediaLab is used to build a mass balance model and to improve the current understanding of the inter-basin exchange. Both tools are open-source, and they are available online.

Dissertation Abstracts International

Dissertation Abstracts International PDF Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 868

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Book Description