Lake Sediment Microbial Communities in the Anthropocene

Lake Sediment Microbial Communities in the Anthropocene PDF Author: Matti Olavi Ruuskanen
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Since the Industrial Revolution at the end of the 18th century, anthropogenic changes in the environment have shifted from the local to the global scale. Even remote environments such as the high Arctic are vulnerable to the effects of climate change. Similarly, anthropogenic mercury (Hg) has had a global reach because of atmospheric transport and deposition far from emission point sources. Whereas some effects of climate change are visible through melting permafrost, or toxic effects of Hg at higher trophic levels, the often-invisible changes in microbial community structures and functions have received much less attention. With recent and drastic warming-related changes in Arctic watersheds, previously uncharacterized phylogenetic and functional diversity in the sediment communities might be lost forever. The main objectives of my thesis were to uncover how microbial community structure, functional potential and the evolution of mercury specific functions in lake sediments in northern latitudes (>54{486}N) are affected by increasing temperatures and Hg deposition. To address these questions, I examined environmental DNA from sediment core samples and high-throughput sequencing to reconstruct the community composition, functional potential, and evolutionary responses to historical Hg loading. In my thesis I show that the microbial community in Lake Hazen (NU, Canada) sediments is structured by redox gradients and pH. Furthermore, the microbes in this phylogenetically diverse community contain genomic features which might represent adaptations to the cold and oligotrophic conditions. Finally, historical Hg pollution from anthropogenic sources has likely affected the evolution of microbial Hg resistance and this deposition can be tracked using sediment DNA on the Northern Hemisphere. My thesis underscores the importance of using culture-independent methods to reconstruct the structure, functional potential and evolution of environmental microbial communities.

Lake Sediment Microbial Communities in the Anthropocene

Lake Sediment Microbial Communities in the Anthropocene PDF Author: Matti Olavi Ruuskanen
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Since the Industrial Revolution at the end of the 18th century, anthropogenic changes in the environment have shifted from the local to the global scale. Even remote environments such as the high Arctic are vulnerable to the effects of climate change. Similarly, anthropogenic mercury (Hg) has had a global reach because of atmospheric transport and deposition far from emission point sources. Whereas some effects of climate change are visible through melting permafrost, or toxic effects of Hg at higher trophic levels, the often-invisible changes in microbial community structures and functions have received much less attention. With recent and drastic warming-related changes in Arctic watersheds, previously uncharacterized phylogenetic and functional diversity in the sediment communities might be lost forever. The main objectives of my thesis were to uncover how microbial community structure, functional potential and the evolution of mercury specific functions in lake sediments in northern latitudes (>54{486}N) are affected by increasing temperatures and Hg deposition. To address these questions, I examined environmental DNA from sediment core samples and high-throughput sequencing to reconstruct the community composition, functional potential, and evolutionary responses to historical Hg loading. In my thesis I show that the microbial community in Lake Hazen (NU, Canada) sediments is structured by redox gradients and pH. Furthermore, the microbes in this phylogenetically diverse community contain genomic features which might represent adaptations to the cold and oligotrophic conditions. Finally, historical Hg pollution from anthropogenic sources has likely affected the evolution of microbial Hg resistance and this deposition can be tracked using sediment DNA on the Northern Hemisphere. My thesis underscores the importance of using culture-independent methods to reconstruct the structure, functional potential and evolution of environmental microbial communities.

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
Publisher:
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.

A Practicum Project Researching the Microbial Community in Sediment Cores and the Current Chemical Parameters of Lake Qinghai, China

A Practicum Project Researching the Microbial Community in Sediment Cores and the Current Chemical Parameters of Lake Qinghai, China PDF Author: Nicole Kay Berzins
Publisher:
ISBN:
Category : Biotic communities
Languages : en
Pages : 23

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Book Description
Saline lakes at high altitudes represent an important and extreme microbial ecosystem, yet little is known about microbial diversity in such environments. The objective of this study was to examine the change of microbial diversity from the bottom of the lake to sediments from Qinghai Lake and the two sister lakes, Erhai and Garhi Lake in China. The lakes are saline and alkaline and are located on the Qinghai-Tibetan Plateau at an altitude of 3196 m above sea level. An interdisciplinary approach was taken in this long term study and specifically this report provides in depth laboratory cultivation and enrichment procedures along with field results. This data was used to assess microbial communities in the lake ecosystems and better understand the bacterial responses to climatic and environmental changes of Qinghai Lake.

Tracking Environmental Change Using Lake Sediments

Tracking Environmental Change Using Lake Sediments PDF Author: Eric Capo
Publisher: Springer Nature
ISBN: 3031437993
Category : Science
Languages : en
Pages : 450

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Book Description
This book, entitled Tracking Environmental Change Using Lake Sediments: Volume 6 – Sedimentary DNA, provides an overview of the applications of sedimentary DNA-based approaches to paleolimnological studies. These approaches have shown considerable potential in providing information about the long-term changes of overall biodiversity in lakes and their watersheds in response to natural and anthropogenic changes, as well as tracking human migrations over the last thousands of years. Although the first studies investigating the preservation of these molecular proxies in sediments originate from the late-1990s, the number of scientific publications on this topic has increased greatly over the last five years. Alongside numerous ecological findings, several sedimentary DNA studies have been dedicated to understanding the reliability of this approach to reconstruct past ecosystem changes. Despite the major surge of interest, a comprehensive compilation of sedimentary DNA approaches and applications has yet to be attempted. The overall aim of this DPER volume is to fill this knowledge gap.

LOCAL ADAPTATION OF MICROBIAL COMMUNITIES ALONG GEOCHEMICAL SPATIAL GRADIENTS IN SEDIMENTS OF THE LAKE ERIE REGION

LOCAL ADAPTATION OF MICROBIAL COMMUNITIES ALONG GEOCHEMICAL SPATIAL GRADIENTS IN SEDIMENTS OF THE LAKE ERIE REGION PDF Author: Matthew John Hoostal
Publisher:
ISBN:
Category : Erie, Lake
Languages : en
Pages : 189

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Book Description
Lake Erie demonstrates the greatest productivity of the Laurentian Great Lakes, yet has been critically impacted by anthropogenic activities throughout the Lake Erie watershed. Lake Erie is comprised of three major basins, with east-to-west gradients of increasing drainage areas, increasing riverine inputs of nutrients and xenobiotics, as well as decreasing depth. These large-scale geochemical gradients may be expected to result in spatial patterns of microbial community composition, nutrient cycling, and xenobiotic transformation. As such, Lake Erie provides an excellent system to examine the local adaptation of microbial communities throughout a large freshwater ecosystem. Spatial patterns of microbial community composition, as well as functional diversity, across the three basins of Lake Erie were assessed to examine the potential adaptation of microbial communities to local selective pressures. Community composition was investigated through the generation of 16S rDNA libraries, while functional diversity was evaluated with substrate-induced respiration (SIR) and extracellular enzyme activities (EEA) profiles. EEA profiles were subsequently measured to examine microbial community resilience to metal inoculations in sediments contaminated with heavy metals compared to relatively pristine sediments. Bioinformatic studies of bacterial genes involved in the efflux of heavy metals from the cell were performed to provide a conceptual framework of how horizontal gene transfer may expedite the adaptation of bacterial communities to heavy metal stress. Finally, the local adaptation of bacterial communities to PCBs and PAHs was assessed by comparing the diversity of bphA, a gene that initiates PCB metabolism, in polluted and relatively unpolluted sediments within the Lake Erie watershed. Collectively, results suggested large-scale spatial patterns of microbial community composition, functional diversity, and metabolic resilience consistent with the local adaptation of sediment bacterial communities to allochthonous inputs of organic matter and heavy metal pollutants into Lake Erie. Furthermore, estimates of diversity from bphA environmental gene libraries suggest that PCB and PAH contamination represents a driving force in the adaptation of microbial communities in polluted sediments. Results from this study suggest that microbial communities are highly integrated assemblages of multiple taxa locally adapted to differential inputs of nutrients and xenobiotics across geochemical gradients within freshwater ecosystems.

Microbial Ecotoxicology Advances to Improve Environmental and Human Health Under Global Change

Microbial Ecotoxicology Advances to Improve Environmental and Human Health Under Global Change PDF Author: Fabrice Martin-Laurent
Publisher: Frontiers Media SA
ISBN: 2889749215
Category : Science
Languages : en
Pages : 320

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Book Description


Climate Change and Microbes

Climate Change and Microbes PDF Author: Javid A. Parray
Publisher: CRC Press
ISBN: 1000410005
Category : Nature
Languages : en
Pages : 321

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Book Description
This book provides an enlightening picture of the role of microbes for sustaining life systems and how climatic factors will change the course of the processes. Climate Change and Microbes: Impacts and Vulnerability explores the little-addressed issue of the effects of climate change on microbial ecosystems and the influence of climate change on microbiome diversity across various habitats and regions. Recent years have seen the evidence that microbial communities are neither immune to disruption nor do they have the capacity to recover completely after a stressful climate event. This volume documents the important role of microorganisms as climate engineers and considers mitigation and adaptation strategies as well. It goes on to present the research that addresses a diverse array of topics on the impact of climate change on plant-microbe interactions and microbial aquatic life and change-induced aggravations in microbial populations and processes. The book also addresses microbial foodborne diseases resulting from challenging climates. Other topics include algae as indicators of climate change and strategies for facilitating sustainable agro-ecosystems. This book will be immensely helpful in the study of plant microbiology, agricultural sciences, biotechnology, climate science, and environmental microbiology. It will also be applicable to the field of microbial biotechnology, agricultural, and other life and environmental sciences.

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.

Riparian Landscapes

Riparian Landscapes PDF Author: George Patrick Malanson
Publisher: Cambridge University Press
ISBN: 0521384311
Category : Nature
Languages : en
Pages : 308

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Book Description
Riparian Landscapes examines the ecological systems of streamside and floodplain areas from the perspective of landscape ecology. The specific spatial pattern of riparian vegetation is seen as a result of, and a control on, the ecological, geomorphological, and hydrological processes that operate along rivers. Riparian structures are controlled by the spatial dynamics of channels, flooding and soil moisture. These dynamics are part of integrated cascades of water, sediment, nutrients and carbon, to which animal and plant species respond in ways that illuminate community structure and competition. The role of the riparian zone in controlling species distribution and abundance is discussed. Intelligent management of these valuable ecological resources is highlighted. The potential for linking hydrological, geomorphological and ecological simulation models is also explored. This book will be of interest to graduate and professional research workers in environmental science, ecology and physical geography.

Microbial Ecology of Lake Plußsee

Microbial Ecology of Lake Plußsee PDF Author: Jürgen Overbeck
Publisher: Springer Science & Business Media
ISBN: 1461226066
Category : Science
Languages : en
Pages : 408

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Book Description
Lake Plußsee is a small eutrophic kettle lake in northern Germany. Because it is sheltered and has no inflow from rivers, the Plußsee exhibits stable stratification and is especially suitable for limnological studies. This book presents the results of extensive research conducted on the ecophysiology of microorganisms - principally bacteria - at the Plußsee over the past several decades. It begins with three chapters on the general limnological state of the lake: physical factors, inorganic nutrients, plankton composition and succession, fish fauna, etc. These chapters are followed by discussions of dissolved organic matter and photosynthetic production of organic matter by phytoplankton. The remainder of the book addresses the dynamics of structure, function and metabolism of the microorganisms in the Plußsee.