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Author : Jamie S. Foster
Release : 2019-12-23
Genre :
Kind : eBook
Book Rating : 520/5 ( reviews)
Book Synopsis Characterizing Modern Microbialites and The Geobiological Processes Underlying Their Formation by : Jamie S. Foster
Download or read book Characterizing Modern Microbialites and The Geobiological Processes Underlying Their Formation written by Jamie S. Foster. This book was released on 2019-12-23. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Scott R. Beeler
Release : 2019
Genre :
Kind : eBook
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Book Synopsis Understanding the Meaning of Microbialites as Geobiological Archives by : Scott R. Beeler
Download or read book Understanding the Meaning of Microbialites as Geobiological Archives written by Scott R. Beeler. This book was released on 2019. Available in PDF, EPUB and Kindle. Book excerpt: Microbialites, sedimentary structures formed from the interaction of microorganisms with their environment, provide one of the oldest and most complete records of life on Earth, making them an invaluable tool in the field of geobiology. However, much of the information that could be gained from microbialites remains obscured due to our incomplete understanding of how variability in the microbial, geochemical, and physical processes driving their formation affect their morphological and geochemical characteristics. Modern environments of active microbialite formation provide the opportunity to study the relationship between variability in these environmental processes and the resultant mineral product and can act as an analog for understanding ancient examples. However, compared to the vast number of microbialites preserved in the geologic record, microbialite forming environments are relatively rare on modern Earth generating concerns about the generalizability of the knowledge gained from these environments and highlighting the need for study of additional modern settings. The work presented in this dissertation analyzes the processes controlling the formation, morphogenesis, and geochemical compositions of the microbialites of Laguna Negra, Argentina, a location which had previously been understudied compared to other modern environments. Specifically, we investigated the processes controlling the megascale distributions of microbialites, the stable isotopic compositions of the carbonate minerals comprising the structures, and the lipid biomarker compositions preserved in the microbialites. Our results showed that each of these characteristics of microbialites reflect to varying degrees the biological, geochemical, and physical processes that control their formation. Overall, this work highlights the importance of a multifaceted approach to the analysis of microbialites integrating multiple lines of evidence in order to understand the processes controlling their formation and growth and provides a stronger framework for interpreting their meaning in the geologic record.
Author : Kurt O. Konhauser
Release : 2009-03-12
Genre : Science
Kind : eBook
Book Rating : 021/5 ( reviews)
Book Synopsis Introduction to Geomicrobiology by : Kurt O. Konhauser
Download or read book Introduction to Geomicrobiology written by Kurt O. Konhauser. This book was released on 2009-03-12. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Geomicrobiology is a timely and comprehensive overview of how microbial life has affected Earth’s environment through time. It shows how the ubiquity of microorganisms, their high chemical reactivity, and their metabolic diversity make them a significant factor controlling the chemical composition of our planet. The following topics are covered: how microorganisms are classified, the physical constraints governing their growth, molecular approaches to studying microbial diversity, and life in extreme environments bioenergetics, microbial metabolic capabilities, and major biogeochemical pathways chemical reactivity of the cell surface, metal sorption, and the microbial role in contaminant mobility and bioremediation/biorecovery microbiological mineral formation and fossilization the function of microorganisms in mineral dissolution and oxidation, and the industrial and environmental ramifications of these processes elemental cycling in biofilms, formation of microbialites, and sediment diagenesis the events that led to the emergence of life, evolution of metabolic processes, and the diversification of the biosphere. Artwork from the book is available to instructors at www.blackwellpublishing.com/konhauser.
Author : W.E. Krumbein
Release : 2013-11-11
Genre : Science
Kind : eBook
Book Rating : 938/5 ( reviews)
Book Synopsis Fossil and Recent Biofilms by : W.E. Krumbein
Download or read book Fossil and Recent Biofilms written by W.E. Krumbein. This book was released on 2013-11-11. Available in PDF, EPUB and Kindle. Book excerpt: MICROBIAL BIOFILMS: PROTECTIVE NICHES IN ANCIENT AND MODERN GEOMICROBIOLOGY J. W. Costerton and Paul Stoodley Center for Biofilm Engineering Montana State University As this book is published based on discussions of a conference that was held in 2001, it may be useful to provide an update on the most recent revelations about biofilms, so that this excellent exposition of the contribution of microbial biofilms to geological processes may be placed in a modem context. The importance of the contribution of microbial biofilms to global processes is only now being appreciated as it is revealed that all terrestrial surfaces are teeming with microbial life in the form of biofilm communities. These communities live on soil particles, in rock fissures, marine and river sediments and at the very extremes of terrestrial habitats from inside Antarctic ice to the walls of deep sea hydrothermal vents. The contribution of these biofilm communities generally went unrecognized because it was the water that was where microbiologists looked for life, not the surfaces, although, evidence of the early association of microbes with surfaces was in fact present in the fossil record (Rasmussen, 2000; Reysenbach, and Cady, 2001). It is also revealing that biofilm formation is found in prokaryotes from the most deeply rooted branches of the phylogenetic tree in both the Archaea and Bacteria kingdoms, the Korarchaeota and Aquificales respectively (Jahnke et al. 2001; Reysenbach et al. 2000).
Author : Anthony G. Nitti
Release : 2010
Genre :
Kind : eBook
Book Rating : /5 ( reviews)
Book Synopsis Microbialites from the Freshwater System of Cuatro Ciénegas, Mexico by : Anthony G. Nitti
Download or read book Microbialites from the Freshwater System of Cuatro Ciénegas, Mexico written by Anthony G. Nitti. This book was released on 2010. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Modern microbialites are carbonate-precipitating microbial mats and represent the closest living analogues to ancient stromatolites. These ancient carbonate formations are the oldest fossil evidence of life on Earth; however, our comprehension of their relationship to early earth ecosystems relies heavily on understanding the formation of modern microbialites. Research regarding these formation processes has suggested that chemical constraints of CaCO3 precipitation vary on sub-millimeter spatial scales within the living microbial community. In an attempt to shed light on the importance of these chemical microenvironments, this study focused on understanding the spatial distribution of the organisms and processes involved in the formation of modern microbialites. This was accomplished by isolating five visually distinct layers from the upper 2 - 3 cm of an actively forming microbialite found in the freshwater system of Cuatro Ciénegas, Mexico. Each layer was analyzed using genomic, molecular organic, and stable isotopic techniques. Bacterial diversity was determined by 16S rRNA gene analyses, lipid biomarker content was detected by GC-MS, and carbon isotope composition of organic matter and CaCO3 were used as indicators of specific microbial processes. Results of the 16S rRNA gene analysis showed that there is little overlap in the community composition of individual layers. Approximately 90% of the ribotypes identified in the microbialite were unique to a single layer. Furthermore, the relative accretion of CaCO3 at each layer was used to connect the distribution of organisms and processes with two specific zones of CaCO3 precipitation. The first zone of CaCO3 accretion, which accounted for approximately 55% of total CaCO3 accumulation, is found in the surface two layers of the microbialites and dominated by photoautotrophic cyanobacteria and algae. The second zone of CaCO3 precipitation, found at the interior (layers 4 and 5), is composed primarily of heterotrophic proteobacteria and dominated by sulfate-reducing delta-proteobacteria. The lipid content of the microbialite reflected the community structure as determined by genomics. Numerous photosynthetic biomarkers were detected and decreased in abundance with depth, indicating the important function of heterotrophic degradation. Additionally, the detection of sulfurized phytol compounds in layer 5 highlighted an important mechanism for the preservation of biogenic signatures, and reflected both the abundance of phototrophic organisms and sulfate-reducing bacteria. In combination, these interdisciplinary analyses provided an understanding of microbial community composition and metabolism while indicating the spatial relationship to CaCO3 formation and the preservation of distinct biochemical signatures.
