13 items with the tag “hydrothermal

  • Stoichiometry of Life, Task 2a: Field Studies - Yellowstone National Park
    NAI 2009 Arizona State University Annual Report

    We are investigating how the element requirements of microbes are affected by element availability in their environment in Yellowstone National Park, where there are extreme variations in the abundances of bioessential elements in addition to extremes of temperature and pH. In Year 1 we organized a multi-disciplinary field expedition to collect samples and conduct experiments. Analyses of these samples is now underway.

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2 7.2
  • Chemolithotrophic Microbial Oxidation of Insoluble Fe(II)-Bearing Minerals
    NAI 2009 University of Wisconsin Annual Report

    Ferrous iron (Fe(II)) can serve as an energy source for a wide variety of chemolithotrophic microorganisms (organisms that gain energy from metabolism of inorganic compounds). Thought to be one of the oldest forms of microbial metabolism on Earth, Fe(II) oxidation may also have played a role in past (and possibly, present) life on Mars, whose crust is rich in Fe(II)-bearing silicate minerals (e.g. ultramafic basalt rocks). The initial goal of this project is to determine whether an established chemolithoautotrophic Fe(II)-oxidizing, nitrate-reducing culture can grow by oxidation of Fe(II) in basalt glass. Preliminary experiments suggest that the culture is able to oxidize a significant portion of the Fe(II) content of fresh basalt glass from Kilauea, a shield volcano in Hawaii that represents an analog for ancient volcanic activity on Mars.

    ROADMAP OBJECTIVES: 4.1 6.1 7.1
  • Habitability of Water-Rich Environments, Task 4: Evaluate the Habitability of Ancient Aqueous Solutions on Mars
    NAI 2009 Arizona State University Annual Report

    We aim to reconstruct the compositions of ancient fluids on Mars by combining computational models with data on the mineralogy of Mars surface materials as they are preserved today. This effort requires that we better understand how well the types of data obtained today and in future missions reflects the mineralogy that exists today. In this task, we have begun to collect such data at Yellowstone National Park, an analog for possible hydrothermal sites on Mars, and have advanced the use of thermodynamic models to interpret observed mineralogical assemblages.

    ROADMAP OBJECTIVES: 2.1
  • The Deep Hot Biosphere: Expedition 331 of the Integrated Ocean Drilling Program (IODP)
    NAI 2010 University of Hawaii, Manoa Annual Report

    Hydrothermal systems on the seafloor, and their associated submarine hot springs, are one of the leading candidates for the setting in which life originated on planet Earth some 4 billion years ago. Today these systems are known to harbor active and diverse communities of microbes, both bacteria and archaea, which thrive on the high temperatures and the abundant sources of chemical energy supplied by reduced chemical species generated from magma and by water-rock reactions within the hydrothermal system. From September 1 through October 4, 2010, we drilled into an active high-temperature hydrothermal system in the Okinawa Trough, an actively rifting back-arc basin that lies in a transitional region between continental and oceanic crust, northwest of the island of Okinawa in the western Pacific Ocean. The objectives of this drilling were to investigate microbial communities with the hydrothermal system and their geochemical and geophysical setting.

    ROADMAP OBJECTIVES: 5.3 7.1
  • Stoichiometry of Life, Task 2a: Field Studies - Yellowstone National Park
    NAI 2010 Arizona State University Annual Report

    Field work and subsequent laboratory analysis is an integral part of following the elements. One of our field areas is the hot spring ecosystems of Yellowstone, which are dominated by microbes, and where reactions between water and rock generate diverse chemical compositions.
    These natural laboratories provide numerous opportunities to test our ideas about how microbes respond to different geochemical supplies of elements. Summer field work and lab work the rest of the year includes characterizing the natural systems, and controlled experiments on the effects of changing nutrient and metal concentrations (done so as to not impact the natural features!).

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2 7.2
  • Habitability of Water-Rich Environments, Task 4: Evaluate the Habitability of Ancient Aqueous Solutions on Mars
    NAI 2010 Arizona State University Annual Report

    On Earth, hydrothermal systems teem with life and such systems could have been widespread in the solar system. The Mars habitability task has been focusing on understanding how to identify the fingerprints of hydrothermal processes in the ancient rock record, while assessing the potential of hydrothermal deposits to preserve signatures of life. The recent discovery of silica-rich hydrothermal deposits by the Mars Exploration Rover, Spirit, has provided renewed interest in hydrothermal deposits as targets for future in situ robotic missions and sample returns for Astrobiology.

    ROADMAP OBJECTIVES: 2.1
  • Project 2A: Chemolithotrophic Microbial Oxidation of Basalt Glass
    NAI 2010 University of Wisconsin Annual Report

    Ferrous iron (Fe(II)) can serve as an energy source for a wide variety of chemolithotrophic microorganisms (organisms that gain energy from metabolism of inorganic compounds). Fe(II) oxidation may have played a role in past (and possibly, present) life on Mars, whose crust is rich in Fe(II)-bearing silicate minerals (e.g. ultramafic basalt rocks). The goal of this project is to determine whether an established chemolithoautotrophic Fe(II)-oxidizing, nitrate-reducing culture can grow by oxidation of Fe(II) in basalt glass. Experiments showed that the culture is able to oxidize a significant portion (approximately 1%) of the Fe(II) content of fresh basalt glass from Kilauea, a shield volcano in Hawaii that represents an analog for ancient volcanic activity on Mars. The ratio of Fe(II) oxidized to nitrate reduced was consistent with the expected 1:5 stoichiometry, suggesting that the culture oxidized Fe(II) with nitrate in a manner analogous to its metabolism of other (e.g. aqueous) Fe(II) forms.

    ROADMAP OBJECTIVES: 2.1 6.2 7.1
  • Stoichiometry of Life, Task 2a: Field Studies - Yellowstone National Park
    NAI 2011 Arizona State University Annual Report

    Field work and subsequent laboratory analysis is an integral part of following the elements. One of our field areas is the hot spring ecosystems of Yellowstone, which are dominated by microbes, and where reactions between water and rock generate diverse chemical compositions. These natural laboratories provide numerous opportunities to test our ideas about how microbes respond to different geochemical supplies of elements. Summer field work and lab work the rest of the year includes characterizing the natural systems, and controlled experiments on the effects of changing nutrient and metal concentrations (done so as to not impact the natural features!).

    ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 6.2 7.2
  • Habitability of Water-Rich Environments, Task 4: Evaluate the Habitability of Ancient Aqueous Solutions on Mars
    NAI 2011 Arizona State University Annual Report

    Field, laboratory, and numerical modeling studies have been performed to understand the chemical processes and mineralogy relevant to low- and high-temperature aqueous alteration processes on ancient Mars. Results show that significant amounts of aqueous solutions could have been involved in the formation of secondary minerals (silica, clays) observed on Mars, with important implications for its past habitability.

    ROADMAP OBJECTIVES: 2.1
  • Project 2F: Potential for Lithotrophic Microbial Oxidation of Fe(II) in Basalt Glass
    NAI 2012 University of Wisconsin Annual Report

    Ferrous iron (Fe(II)) can serve as an energy source for a wide variety of chemolithotrophic microorganisms (organisms that gain energy from metabolism of inorganic compounds). Fe(II) oxidation may have played a role in past (and possibly, present) life on Mars, whose crust is rich in primary Fe(II)-bearing silicate minerals, as well as Fe-bearing clay minerals formed during weathering of primary silicates. This project examined the potential for microbial oxidation of Fe(II) in basaltic glass. Recent research suggests that near‐surface hydrothermal venting may have occurred during past periods of active volcanic/tectonic activity on Mars. Such activities could have produced basalt glass phases that might have served as energy sources for chemolithotrophic microbial activity. Previous and ongoing NAI‐supported studies have shown that an established chemolithoautotrophic Fe(II)‐oxidizing, nitrate‐reducing culture can grow by oxidation of Fe(II) insoluble Fe(II)‐bearing phyllosilicate phases such as biotite and smectite. The initial goal of this project was to determine whether or not this culture is capable of oxidizing Fe(II) in basalt glass. In addition we tested basaltic glass oxidation by a culture of Desulfitobacterium frappieri, as previous studies demonstrated that D. frappieri is capable of nitrate-dependent oxidation of structural Fe(II) in smectite. Finally, in situ and enrichment culturing experiments were conducted to determine whether indigenous Fe(II)-oxidizing organisms in a groundwater iron seep were capable of colonization and oxidation of basaltic glass. The results of these experiments showed that while the various cultures were readily capable of smectite oxidation with nitrate, none were able to carry-out significant oxidation of Fe(II) in basalt glass. We speculate that Fe(II) atoms in the amorphous glass are somehow occluded and therefore not accessible to outer membrane cytochrome systems thought to be involved in extracellular Fe(II) oxidation.

    ROADMAP OBJECTIVES: 2.1 5.1 5.3