Microbial ecology in Azores deep-seafloor hydrothermal environments.
The world’s oceans cover two-thirds of the planet’s surface being by far the largest habitat on Earth. The marine habitats range from sunlight surface waters to ocean trenches 11,000 m deep with pressures exceeding 1000 bar. Water temperatures range from sea ice, in the polar regions, to over 300 ºC...
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
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Universidade dos Açores
2018
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| Online Access: | https://archimer.ifremer.fr/doc/00840/95203/102897.pdf https://archimer.ifremer.fr/doc/00840/95203/ |
| Summary: | The world’s oceans cover two-thirds of the planet’s surface being by far the largest habitat on Earth. The marine habitats range from sunlight surface waters to ocean trenches 11,000 m deep with pressures exceeding 1000 bar. Water temperatures range from sea ice, in the polar regions, to over 300 ºC, at deep-sea hydrothermal vents. Microorganisms are able to survive and grow throughout these environments, including the subsurface and the deep-sea. Deep- sea hydrothermal systems represent an important interface between the lithosphere and the oceans, and are considered to be “windows” into the subsurface biosphere. At these locations, thermally charged hydrothermal fluids, enriched with metal compounds and dissolved gases, are ejected into the ocean, providing conditions for supporting chemosynthesis and microbial growth. Extremophile organisms have adapted to the high pressures and temperature shifts, developed novel physiological strategies to thrive in such conditions resorting to unique enzymes and proteins with interesting activities and potential biotechnological applications. Chemoautotrophic Bacteria and Archaea are the primary source of nutrition for the overall organisms dwelling around the vents. They are primary producers of organic carbon, able to establish intricate chemosynthetic symbioses with micro- and macroorganisms, and to transfer the energy up to the food web, sustaining life in the deep-sea. Because of their unique features, they are considered plausible analogues to the early microorganisms of Earth. Therefore, the study of such putative early microbes may help us understanding the origin and evolution of life, and the adaptation mechanisms to these extreme environmental conditions. Moreover, these microorganisms are potentially playing important roles in global geochemical cycling between crusts and oceans, what makes their distribution and activities in deep-sea floors interesting subjects for contemporary microbial ecologists. So far, the diversity and distribution patterns of ... |
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