Download or read book A Lipid Biomarker and Stable Isotopic Investigation of Ediacaran and Modern Marine Microbial Communities and Carbon Cycling written by Carina Lee and published by . This book was released on 2016 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented here are two studies of marine organic matter preservation and cycling, from the enigmatic late Ediacaran Shuram excursion of South Oman and from the modern hypersaline microbial mats of Guerrero Negro, Baja California, Mexico.
Download or read book Marine Organic Matter Biomarkers Isotopes and DNA written by J. K. Volkman and published by Springer Science & Business Media. This book was released on 2006-02-09 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: The oceans contain a great biodiversity of marine organisms. They include a rich variety of unusual genes and biochemistries and hence a diverse array of organic compounds ranging from colourful carotenoids and chlorophylls to lipids with structures ranging from the simple to the complex. This volume brings together ten chapters on the occurrence and identification of the lipid biomarkers and of pigments in marine waters. It describes how they can be used in conjunction with stable isotopes and molecular biology to ascertain the sources and fate of organic matter (both natural and pollutant) in the sea and underlying sediments. The authors are each experts in their field and the chapters provide both an overview of the state-of-the-art and knowledge gaps together with abundant detail to satisfy the needs of specialists and non-specialists alike.
Download or read book Molecular Signatures of Microbial Metabolism in the Marine Water Column written by Jenan J. Kharbush and published by . This book was released on 2015 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lipid biomarkers are valuable tools in studies of microbial metabolic diversity and function in both past and present marine ecosystems, but the distribution and biological sources of many of these biomarkers in the modern ocean have yet to be sufficiently defined. This dissertation examines two major classes of lipid biomarker compounds that are widely distributed in marine environments: hopanoids, biomarkers for bacteria, and intact polar diacylglycerols (IP-DAGs), potential biological tracers of recent carbon and nutrient cycling. The distribution and structural diversity of these lipid compounds is analyzed in tandem with genetic and metagenomic data, both expanding the knowledge related to the structural distribution of these lipids in the marine environment, and illuminating key aspects of the ecology of the producing organisms. This work is detailed in six chapters, consisting of an introduction, four research-oriented chapters, and concluding remarks. Chapters 2, 3, and 4 focus on the bacterial hopanoids. First, analysis of hopanoid structural diversity and abundance across oxygen gradients in the Santa Barbara Basin was complemented by a genetic survey, identifying a potential connection between hopanoid production and metabolic strategies associated with low oxygen environments. Next, this connection was further investigated using qPCR and surveys of existing metagenomes to quantify the relative abundance of groups of hopanoid producers in low oxygen regions of the Eastern North Pacific and Eastern Tropical Pacific oxygen minimum zones. Results revealed that dominant hopanoid producers in these regions are not Proteobacteria as previously hypothesized but instead are nitrite-utilizing organisms such as nitrite-oxidizing and anaerobic ammonia-oxidizing bacteria. Finally, a survey of an extensive metagenomic dataset from the Red Sea illuminated the distribution of hopanoid producers in a biogeochemically-distinct environment relative to those previously analyzed, and confirming that hopanoid producers may also play roles in marine nitrogen cycling. Chapter 5 details an exploratory investigation of the structural distribution of various classes of IP-DAGs, in the oligotrophic Tonga Trench. Results provide new insight into potential biological sources of IP-DAGs, and identify structures that may be useful as indicators of the contribution of groups of picophytoplankton to export production, or of in situ heterotrophic production at depth.
Download or read book Marine Organic Matter Biomarkers Isotopes and DNA written by J. K. Volkman and published by Springer. This book was released on 2010-11-25 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: The oceans contain a great biodiversity of marine organisms. They include a rich variety of unusual genes and biochemistries and hence a diverse array of organic compounds ranging from colourful carotenoids and chlorophylls to lipids with structures ranging from the simple to the complex. This volume brings together ten chapters on the occurrence and identification of the lipid biomarkers and of pigments in marine waters. It describes how they can be used in conjunction with stable isotopes and molecular biology to ascertain the sources and fate of organic matter (both natural and pollutant) in the sea and underlying sediments. The authors are each experts in their field and the chapters provide both an overview of the state-of-the-art and knowledge gaps together with abundant detail to satisfy the needs of specialists and non-specialists alike.
Download or read book Microbial Metabolism in the Deep Ocean written by Roberta Lynn Hansman and published by . This book was released on 2008 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: To address the major role microorganisms play in the biogeochemical cycling of carbon and nutrients in the marine environment, the work presented in this dissertation uses a combination of geochemical and molecular biological techniques to investigate carbon and nitrogen metabolism in the planktonic microbial community of the deep ocean. A method was developed to isolate microbial DNA from the marine water column suitable for radiocarbon analysis, which was then applied to determine the sources of carbon fueling microbial production in the mesopelagic. Fresh organic matter delivered from sinking particles was confirmed as an important carbon source for free-living microbes, but the extent of autotrophic carbon fixation was also significant and variable with depth, highlighting the requirement for particle-delivered reduced nitrogen by the total microbial community in the deep ocean. Both findings stressed the importance of constraining particle-derived carbon and nitrogen flux to the deep ocean. The importance of methane as a carbon source in unique environments above cold methane seeps was examined using both stable carbon isotope measurements of microbial DNA and quantitative PCR of the gene encoding for particulate methane monooxygenase. The carbon isotope measurements showed that methane-carbon played an insignificant role in fueling planktonic microbial production in the deep water column just above methane seeps. The PCR measurements substantiated this result by showing that the methane oxidizing community represented only a small percentage of the microbial community in this environment. And finally, bacterial heterotrophic nitrate assimilation was studied and determined to increase with depth and/or nitrate concentration, but appeared to only be a possible nitrogen acquisition method for a small (> 1%) fraction of the bacterial community. Sequencing of the heterotrophic nitrate assimilation gene isolated from the marine environment further demonstrated that these genes were depth stratified. In addition both isotopic analyses and molecular biological techniques such as quantitative PCR indicated distinct differences between free-living and particle-attached microbial communities. Overall, future research efforts should be focused on expanding the current data set, constraining particle flux, and gaining a better understanding of microbial physiology, including in situ growth rates, in the subsurface marine environment.
Download or read book Lipid Biomarkers of Microbial Communities Involved in Carbon Dioxide and Methane Cycling at Volcanic CO2 Vents written by Birte I. Oppermann and published by . This book was released on 2010 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stable Carbon Isotopic Studies of Microbial Lipids from Distinct Geochemical Marine Environments written by Qing-Zeng Zhu and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tracing Organic Matter Pathways in Marine Food Webs Using Fatty Acids and Compound Specific Stable Isotope Analysis written by Stephanie Denise Smith and published by . This book was released on 2015 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic matter inputs to the marine environment vary over seasonal and spatial scales, altering the type and availability of food sources for marine consumers. It is important to identify diet in order to understand basic ecology, characterize trophic interactions, and predict consequences of biotic and abiotic change within a community. Methods of direct observation of diet and feeding can be difficult, so indirect methods have been developed such as analysis of gut contents and fecal pellets. However, these methods only represent a snapshot of the last meal, and provide information about what was ingested, but not what was actually incorporated into consumer tissues. Therefore, biogeochemical approaches such as fatty acid (FA) and stable isotope analyses have been developed, which provide a time-integrated measure of diet. Further, stable isotope measurements of specific FA markers can be used to identify carbon sources, and can be applied to a variety of food web studies (Iverson et al., 2004). The purpose of this research is to examine the linkages between organic carbon sources and trophic transfer by consumers. To achieve this, we use FA biomarkers and compound specific stable isotope analysis (CSIA) to trace carbon cycling. This study has two main components: environmental sampling and experimental research. Chapter 1 demonstrates the use of these tools for elucidating seasonal trophic linkages in invertebrates collected from the Alaskan Arctic coast. Overall, invertebrate diets were characterized by terrestrial, detrital, and carnivorous sources in winter and spring, with a shift toward autochthonous diatom-based diets in summer. Our results demonstrate the importance of terrestrial organic carbon as a subsistence food source in winter, whereas in situ production in summer was critical for accumulating FA stores rich in essential FAs. Chapter 2 is an experimental feeding study designed to quantify the incorporation rates of 18:2n-6 from diet to tissue in Atlantic croaker. Liver tissues accumulated FAs more quickly than muscle tissues, but both tissues reached equilibrium at 5 to 7 weeks. From these experiments, quantitative assessments of diet sources can be made with confidence when using FAs to understand trophic interactions of Atlantic croaker and other similar species.
Download or read book Lipids in Aquatic Ecosystems written by Michael T. Arts and published by Springer Science & Business Media. This book was released on 2009-06-12 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evidence now suggests that the roles of essential fatty acids as growth promoters and as indices of health and nutrition are fundamentally similar in freshwater and marine ecosystems. Lipids in Aquatic Ecosystems integrates this divergent literature into a coordinated, digestible form. Chapters are organized so as to discuss and synthesize the flow of lipids from lower to higher trophic levels, up to and including humans. Linkages between the production, distribution and pathways of these essential compounds within the various levels of the aquatic food webs, and their ultimate uptake by humans and other terrestrial organisms, are highlighted throughout the book. This book will be of interest to researchers and resource managers working with aquatic ecosystems.
Download or read book Marine Biogenic Lipids Fats and Oils written by Robert George Ackman and published by CRC Press. This book was released on 1989-04-30 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph will put the biogenic marine lipids of many organisms in perspective. Up to 100 years ago, fish and shellfish were frequent and major components of our "western" diet. In search of progress and convenience, we have given up many such foods in favor of those produced by "agribusiness" interests. There are different viewpoints on the merits of the marine omage-3 fatty acids and of the terrestrial omega-6 fatty acids in human nutrition, and every individual may have different needs. This monograph should help researchers relate these basic building blocks of lipids in the fascinating world of marine organisms to our contemporary interest in human biochemistry, nutrition, and health.
Download or read book Marine Biogenic Lipids Fats Oils written by Robert George Ackman and published by CRC Press. This book was released on 1989-04-30 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph will put the biogenic marine lipids of many organisms in perspective. Volume 1 of 2.
Download or read book Seasonal Variability of Planktonic Lipid Distributions Abundances and Carbon Isotopic Values in Monterey Bay CA written by Margaret Golan-Bac and published by . This book was released on 1999 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Biomarker and Carbon Isotopic Study of Organic rich Marine Sediments from Two Cainozoic Climate Optima written by Catherine A. Johnson and published by . This book was released on 1996 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemostratigraphy Across Major Chronological Boundaries written by Alcides N. Sial and published by John Wiley & Sons. This book was released on 2018-12-18 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Winner of the 2020 PROSE Award for Earth Science! Exploring environmental changes through Earth’s geological history using chemostratigraphy Chemostratigraphy is the study of the chemical characteristics of different rock layers. Decoding this geochemical record across chronostratigraphic boundaries can provide insights into geological history, past climates, and sedimentary processes. Chemostratigraphy Across Major Chronological Boundaries presents state-of-the-art applications of chemostratigraphic methods and demonstrates how chemical signatures can decipher past environmental conditions. Volume highlights include: Presents a global perspective on chronostratigraphic boundaries Describes how different proxies can reveal distinct elemental and isotopic events in the geologic past Examines the Archaean-Paleoproterozoic, Proterozoic-Paleozoic, Paleozoic-Mesozoic, and Mesozoic-Paleogene boundaries Explores cause-and-effect through major, trace, PGE, and REE elemental, stable, and radiogenic isotopes Offers solutions to persistent chemostratigraphic problems on a micro-global scale Geared toward academic and researchgeoscientists, particularly in the fields of sedimentary petrology, stratigraphy, isotope geology, geochemistry, petroleum geology, atmospheric science, oceanography, climate change and environmental science, Chemostratigraphy Across Major Chronological Boundaries offers invaluable insights into environmental evolution and climatic change. Read the Editors' Vox: https://eos.org/editors-vox/unravelling-the-past-using-elements-and-isotopes
Download or read book Biogeochemical Applications of Compound specific Radiocarbon Analysis written by Ann Pearson and published by . This book was released on 2000 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compound-specific carbon isotopic (delta 13C and delta 14C) data are reported for lipid biomarkers isolated from Santa Monica Basin (SMB) and Santa Barbara Basin (SBB) surface sediments. These organic compounds represent phytoplanktonic, zooplanktonic, bacterial, archaeal, terrestrial, and fossil carbon sources. The lipids include long-chain n-alkanes, fatty acids (as FAMEs), n-alcohols, C(30) mid-chain ketols and diols, sterols, hopanols, and ether-linked C(40)-biphytanes of Archaca. The data show that the carbon source for most of the biomarkers is marine euphotic zone primary production or subsequent heterotrophic consumption of this biomass. Two lipid classes represent exceptions to this finding. Delta 14C values for the n-alkanes are consistent with mixed fossil and contemporary terrestrial plant sources. The archaeal isoprenoid data reflect chemoautotrophic growth below the euphotic zone. The biomarker class most clearly representing marine phytoplanktonic production is the sterols. It is suggested, therefore, that the sterols could serve as paleoceanographic tracers for surface-water DIC. The isotopic data are used to construct two algebraic models. The first calculates the contributions of fossil and modern vascular plant carbon to SMB n-alkanes. This model indicates that the delta 14C of the modern component is +235% (post-bomb) or 0% (pre-bomb). The second model uses these values to determine the origin of sedimentary TOC. The results are comparable to estimates based on other approaches and suggest that approx. 60% of SMB TOC is of marine origin, modern terrestrial and fossil sources contribute approx. 10% each, and the remaining approx. 20% is of unknown origin.
Download or read book Microbial Activity in Marine Sediment Constrained Via Lipid based Stable Isotope Probing written by Weichao Wu and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of marine benthic pelagic coupling on individuals populations and communities implications for carbon cycling in polar seas written by Paul E. Renaud and published by . This book was released on 1998 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
