Mechanisms in Bacterial Utilization of Cellular Debris in the Ocean

Mechanisms in Bacterial Utilization of Cellular Debris in the Ocean PDF Author: Ryan Guillemette
Publisher:
ISBN:
Category :
Languages : en
Pages : 114

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Book Description
This dissertation investigates the mechanisms of bacterial utilization of cells and cellular debris in the ocean. Bacteria are key members of marine ecosystems. They serve as the predominant biotic force acting on marine biogeochemical cycling of organic matter, and exert a strong influence on marine microbial community dynamics via their cell-cell interactions. While scientists have begun to untangle the web of seemingly intractable mechanisms that marine bacteria use to acquire and consume organic matter, many unknowns still remain. This research implements a number of techniques including bacterial production measurements, mass spectrometry, single-cell analyses, and genetics to test two hypotheses: (1) that bacteria can readily respond to a natural pulse of cellular debris from coral mass-spawning, and (2) that contact-dependent predatory bacteria can kill and consume their bacterial prey. Studies conducted off coastal Panama found that coral gametes elevated the organic matter concentration of the surrounding seawater by ~5-fold after a mass spawning event. Bacterial production measurements and 454 pyrosequencing of bromodeoxyuridine-labeled 16S bacterial rRNA genes showed that it was primarily active Rhodobacteraceae, Flavobacteriaceae, and Saprospiraceae taxa that degraded the coral gametes. High resolution mass spectrometry analysis supported this hypothesis, showing trends that indicated microbial alteration of the organic matter pool. This study demonstrated that coastal marine bacteria can readily respond to a large input of autochthonous cellular debris. Contact-dependent bacterial predation was tested by using bacteria with a type 6 secretion system (T6SS+) as model predators in competition assays. Nanoscale secondary ion mass spectrometry analysis showed that T6SS+ Vibrio cholerae utilized carbon from its bacterial prey. V. cholerae also exhibited the ability to utilize DNA and ribosomes from lysed bacteria as nutrients. Additionally, independent competition assays between T6SS+ V. cholerae and 15 different marine bacterial isolates showed that V. cholerae and/or the challenged isolate were killed in 12 out of the 15 assays. The experiments also revealed that the coral and shellfish pathogen, Vibrio coralliilyticus has a functional T6SS. Collectively, these results demonstrate that bacterial antagonism often ends in carnage for one or both of the competing species, and suggest that the susceptible prey are fresh fodder for the victorious bacterium.

Mechanisms in Bacterial Utilization of Cellular Debris in the Ocean

Mechanisms in Bacterial Utilization of Cellular Debris in the Ocean PDF Author: Ryan Guillemette
Publisher:
ISBN:
Category :
Languages : en
Pages : 114

Get Book Here

Book Description
This dissertation investigates the mechanisms of bacterial utilization of cells and cellular debris in the ocean. Bacteria are key members of marine ecosystems. They serve as the predominant biotic force acting on marine biogeochemical cycling of organic matter, and exert a strong influence on marine microbial community dynamics via their cell-cell interactions. While scientists have begun to untangle the web of seemingly intractable mechanisms that marine bacteria use to acquire and consume organic matter, many unknowns still remain. This research implements a number of techniques including bacterial production measurements, mass spectrometry, single-cell analyses, and genetics to test two hypotheses: (1) that bacteria can readily respond to a natural pulse of cellular debris from coral mass-spawning, and (2) that contact-dependent predatory bacteria can kill and consume their bacterial prey. Studies conducted off coastal Panama found that coral gametes elevated the organic matter concentration of the surrounding seawater by ~5-fold after a mass spawning event. Bacterial production measurements and 454 pyrosequencing of bromodeoxyuridine-labeled 16S bacterial rRNA genes showed that it was primarily active Rhodobacteraceae, Flavobacteriaceae, and Saprospiraceae taxa that degraded the coral gametes. High resolution mass spectrometry analysis supported this hypothesis, showing trends that indicated microbial alteration of the organic matter pool. This study demonstrated that coastal marine bacteria can readily respond to a large input of autochthonous cellular debris. Contact-dependent bacterial predation was tested by using bacteria with a type 6 secretion system (T6SS+) as model predators in competition assays. Nanoscale secondary ion mass spectrometry analysis showed that T6SS+ Vibrio cholerae utilized carbon from its bacterial prey. V. cholerae also exhibited the ability to utilize DNA and ribosomes from lysed bacteria as nutrients. Additionally, independent competition assays between T6SS+ V. cholerae and 15 different marine bacterial isolates showed that V. cholerae and/or the challenged isolate were killed in 12 out of the 15 assays. The experiments also revealed that the coral and shellfish pathogen, Vibrio coralliilyticus has a functional T6SS. Collectively, these results demonstrate that bacterial antagonism often ends in carnage for one or both of the competing species, and suggest that the susceptible prey are fresh fodder for the victorious bacterium.

YOUMARES 9 - the Oceans: Our Research, Our Future

YOUMARES 9 - the Oceans: Our Research, Our Future PDF Author: Simon Jungblut
Publisher: Springer Nature
ISBN: 3030203891
Category : Aquatic biology
Languages : en
Pages : 378

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Book Description
This open access book summarizes peer-reviewed articles and the abstracts of oral and poster presentations given during the YOUMARES 9 conference which took place in Oldenburg, Germany, in September 2018. The aims of this book are to summarize state-of-the-art knowledge in marine sciences and to inspire scientists of all career stages in the development of further research. These conferences are organized by and for young marine researchers. Qualified early-career researchers, who moderated topical sessions during the conference, contributed literature reviews on specific topics within their research field. .

Indicators for Waterborne Pathogens

Indicators for Waterborne Pathogens PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309091225
Category : Nature
Languages : en
Pages : 329

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Book Description
Recent and forecasted advances in microbiology, molecular biology, and analytical chemistry have made it timely to reassess the current paradigm of relying predominantly or exclusively on traditional bacterial indicators for all types of waterborne pathogens. Nonetheless, indicator approaches will still be required for the foreseeable future because it is not practical or feasible to monitor for the complete spectrum of microorganisms that may occur in water, and many known pathogens are difficult to detect directly and reliably in water samples. This comprehensive report recommends the development and use of a "tool box" approach by the U.S Environmental Protection Agency and others for assessing microbial water quality in which available indicator organisms (and/or pathogens in some cases) and detection method(s) are matched to the requirements of a particular application. The report further recommends the use of a phased, three-level monitoring framework to support the selection of indicators and indicator approaches.Â

Marine Anthropogenic Litter

Marine Anthropogenic Litter PDF Author: Melanie Bergmann
Publisher: Springer
ISBN: 3319165100
Category : Science
Languages : en
Pages : 456

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Book Description
This book describes how man-made litter, primarily plastic, has spread into the remotest parts of the oceans and covers all aspects of this pollution problem from the impacts on wildlife and human health to socio-economic and political issues. Marine litter is a prime threat to marine wildlife, habitats and food webs worldwide. The book illustrates how advanced technologies from deep-sea research, microbiology and mathematic modelling as well as classic beach litter counts by volunteers contributed to the broad awareness of marine litter as a problem of global significance. The authors summarise more than five decades of marine litter research, which receives growing attention after the recent discovery of great oceanic garbage patches and the ubiquity of microscopic plastic particles in marine organisms and habitats. In 16 chapters, authors from all over the world have created a universal view on the diverse field of marine litter pollution, the biological impacts, dedicated research activities, and the various national and international legislative efforts to combat this environmental problem. They recommend future research directions necessary for a comprehensive understanding of this environmental issue and the development of efficient management strategies. This book addresses scientists, and it provides a solid knowledge base for policy makers, NGOs, and the broader public.

Freshwater Microplastics

Freshwater Microplastics PDF Author: Martin Wagner
Publisher: Springer
ISBN: 3319616153
Category : Science
Languages : en
Pages : 309

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Book Description
This book is open access under a CC BY 4.0 license. This volume focuses on microscopic plastic debris, also referred to as microplastics, which have been detected in aquatic environments around the globe and have accordingly raised serious concerns. The book explores whether microplastics represent emerging contaminants in freshwater systems, an area that remains underrepresented to date. Given the complexity of the issue, the book covers the current state-of-research on microplastics in rivers and lakes, including analytical aspects, environmental concentrations and sources, modelling approaches, interactions with biota, and ecological implications. To provide a broader perspective, the book also discusses lessons learned from nanomaterials and the implications of plastic debris for regulation, politics, economy, and society. In a research field that is rapidly evolving, it offers a solid overview for environmental chemists, engineers, and toxicologists, as well as water managers and policy-makers.

Mechanisms of antibiotic resistance

Mechanisms of antibiotic resistance PDF Author: Jun Lin
Publisher: Frontiers Media SA
ISBN: 2889195260
Category : Antibiotics
Languages : en
Pages : 226

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Book Description
Antibiotics represent one of the most successful forms of therapy in medicine. But the efficiency of antibiotics is compromised by the growing number of antibiotic-resistant pathogens. Antibiotic resistance, which is implicated in elevated morbidity and mortality rates as well as in the increased treatment costs, is considered to be one of the major global public health threats (www.who.int/drugresistance/en/) and the magnitude of the problem recently prompted a number of international and national bodies to take actions to protect the public (http://ec.europa.eu/dgs/health_consumer/docs/road-map-amr_en.pdf: http://www.who.int/drugresistance/amr_global_action_plan/en/; http://www.whitehouse.gov/sites/default/files/docs/carb_national_strategy.pdf). Understanding the mechanisms by which bacteria successfully defend themselves against the antibiotic assault represent the main theme of this eBook published as a Research Topic in Frontiers in Microbiology, section of Antimicrobials, Resistance, and Chemotherapy. The articles in the eBook update the reader on various aspects and mechanisms of antibiotic resistance. A better understanding of these mechanisms should facilitate the development of means to potentiate the efficacy and increase the lifespan of antibiotics while minimizing the emergence of antibiotic resistance among pathogens.

Microplastic in the Environment: Pattern and Process

Microplastic in the Environment: Pattern and Process PDF Author: Michael S. Bank
Publisher: Springer Nature
ISBN: 3030786277
Category : Technology & Engineering
Languages : en
Pages : 364

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Book Description
This open access book examines global plastic pollution, an issue that has become a critical societal challenge with implications for environmental and public health. This volume provides a comprehensive, holistic analysis on the plastic cycle and its subsequent effects on biota, food security, and human exposure. Importantly, global environmental change and its associated, systems-level processes, including atmospheric deposition, ecosystem complexity, UV exposure, wind patterns, water stratification, ocean circulation, etc., are all important direct and indirect factors governing the fate, transport and biotic and abiotic processing of plastic particles across ecosystem types. Furthermore, the distribution of plastic in the ocean is not independent of terrestrial ecosystem dynamics, since much of the plastic in marine ecosystems originates from land and should therefore be evaluated in the context of the larger plastic cycle. Changes in species size, distribution, habitat, and food web complexity, due to global environmental change, will likely alter trophic transfer dynamics and the ecological effects of nano- and microplastics. The fate and transport dynamics of plastic particles are influenced by their size, form, shape, polymer type, additives, and overall ecosystem conditions. In addition to the risks that plastics pose to the total environment, the potential impacts on human health and exposure routes, including seafood consumption, and air and drinking water need to be assessed in a comprehensive and quantitative manner. Here I present a holistic and interdisciplinary book volume designed to advance the understanding of plastic cycling in the environment with an emphasis on sources, fate and transport, ecotoxicology, climate change effects, food security, microbiology, sustainability, human exposure and public policy.

Ocean Acidification

Ocean Acidification PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 030916155X
Category : Science
Languages : en
Pages : 200

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Book Description
The ocean has absorbed a significant portion of all human-made carbon dioxide emissions. This benefits human society by moderating the rate of climate change, but also causes unprecedented changes to ocean chemistry. Carbon dioxide taken up by the ocean decreases the pH of the water and leads to a suite of chemical changes collectively known as ocean acidification. The long term consequences of ocean acidification are not known, but are expected to result in changes to many ecosystems and the services they provide to society. Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean reviews the current state of knowledge, explores gaps in understanding, and identifies several key findings. Like climate change, ocean acidification is a growing global problem that will intensify with continued CO2 emissions and has the potential to change marine ecosystems and affect benefits to society. The federal government has taken positive initial steps by developing a national ocean acidification program, but more information is needed to fully understand and address the threat that ocean acidification may pose to marine ecosystems and the services they provide. In addition, a global observation network of chemical and biological sensors is needed to monitor changes in ocean conditions attributable to acidification.

Marine Biology

Marine Biology PDF Author: Jerónimo Pan
Publisher: CRC Press
ISBN: 0429678533
Category : Nature
Languages : en
Pages : 394

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Book Description
We present you with an updated reference book aimed for upper-level undergraduate and graduate students interested in Marine Biology. The textbook is designed to introduce the fundamentals of marine organisms and their ecological roles in the world’s oceans, and is organized by functional groups, emphasizing marine biodiversity rather than systematics or habitats. Each chapter has been written and peer-reviewed by renowned international experts in their respective fields, and includes updated information on relevant topics, from the microbial loop and primary production in the oceans, to marine megafauna and the impacts of projected climate change on marine life and ecosystems.

Molecular Mechanisms of Plant and Microbe Coexistence

Molecular Mechanisms of Plant and Microbe Coexistence PDF Author: Chandra Shekhar Nautiyal
Publisher: Springer Science & Business Media
ISBN: 3540755756
Category : Science
Languages : en
Pages : 491

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Book Description
Molecular Mechanisms of Plant and Microbe Coexistence presents studies on the complex and manifold interactions of plants and microbes at the population, genomics and proteomics level. The role of soil microbial diversity in enhancing plant health and plant microbe beneficial symbioses is discussed. Microbial communities are shown in the light of evolution. Main topics include genome coexistence and the functional genomics and proteomics of plant-associated microbes, which could form the basis for new environmentally benign strategies to combat infectious plant diseases and regulate plant growth. Further chapters focus on the role of signaling during the different stages of plant microbe coexistence, in symbiotic or pathogenic relationships, in quorum sensing and plant viral infections. Methods for studying the interactions in the root zone complement the book, which will certainly be of relevance in the practical application to agriculture, food security and for maintaining the balance of our ecosystems.