Physiology, Metabolism, and Fossilization of Hot-Spring Filamentous Microbial Mats
| Autor: | Isaac K. O. Cann, Radhika S. Khetani, Kyle W. Fouke, Joseph R. Weber, Peter M. Yau, Robert A. Sanford, Charles R Werth, Glenn Fried, Vincent Bulone, Chris L. Wright, Mayandi Sivaguru, Mark Band, Dag Ahrén, Yiran Dong, Alvaro G. Hernandez, William P. Inskeep, Bruce W. Fouke, Christopher J. Fields, Kathleen M. Keating, Vaibhav Srivastava, Brian S. Imai |
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| Rok vydání: | 2019 |
| Předmět: |
DNA
Bacterial Geologic Sediments Filamentous microbial mats 010504 meteorology & atmospheric sciences Sulfurihydrogenibium Microorganism Physiology chemistry.chemical_element 01 natural sciences Hot Springs Carbon Cycle Extremophiles Extracellular polymeric substance RNA Ribosomal 16S 0103 physical sciences Ecosystem Microbial mat Hot-spring 010303 astronomy & astrophysics Research Articles Phylogeny 0105 earth and related environmental sciences Travertine Hot spring Bacteria biology Fossils Microbiota Carbon fixation Biodiversity Gene Expression Regulation Bacterial biology.organism_classification Agricultural and Biological Sciences (miscellaneous) Sulfur chemistry Genes Bacterial Space and Planetary Science Fimbriae Proteins Oxidation-Reduction Biomarkers |
| Zdroj: | Astrobiology |
| ISSN: | 1557-8070 1531-1074 |
| Popis: | The evolutionarily ancient Aquificales bacterium Sulfurihydrogenibium spp. dominates filamentous microbial mat communities in shallow, fast-flowing, and dysoxic hot-spring drainage systems around the world. In the present study, field observations of these fettuccini-like microbial mats at Mammoth Hot Springs in Yellowstone National Park are integrated with geology, geochemistry, hydrology, microscopy, and multi-omic molecular biology analyses. Strategic sampling of living filamentous mats along with the hot-spring CaCO3 (travertine) in which they are actively being entombed and fossilized has permitted the first direct linkage of Sulfurihydrogenibium spp. physiology and metabolism with the formation of distinct travertine streamer microbial biomarkers. Results indicate that, during chemoautotrophy and CO2 carbon fixation, the 87–98% Sulfurihydrogenibium-dominated mats utilize chaperons to facilitate enzyme stability and function. High-abundance transcripts and proteins for type IV pili and extracellular polymeric substances (EPSs) are consistent with their strong mucus-rich filaments tens of centimeters long that withstand hydrodynamic shear as they become encrusted by more than 5 mm of travertine per day. Their primary energy source is the oxidation of reduced sulfur (e.g., sulfide, sulfur, or thiosulfate) and the simultaneous uptake of extremely low concentrations of dissolved O2 facilitated by bd-type cytochromes. The formation of elevated travertine ridges permits the Sulfurihydrogenibium-dominated mats to create a shallow platform from which to access low levels of dissolved oxygen at the virtual exclusion of other microorganisms. These ridged travertine streamer microbial biomarkers are well preserved and create a robust fossil record of microbial physiological and metabolic activities in modern and ancient hot-spring ecosystems. |
| Databáze: | OpenAIRE |
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