NASA Astrobiology Institute (NAI)

1. Biosignatures in chemosynthetic and photosynthetic systems

   Project Investigators: David Blake, Richard Castenholz, Nikolaus Finke, Tori Hoehler, Victoria Orphan, Allan Treiman, Pieter Visscher, Marilyn Vogel, Dawn Cardace, Verona` Vandieken

   Other Project Members

   Daniel Albert (Collaborator)

   Alex Bradley (Doctoral Student)

   Don Canfield (Collaborator)

   David Des Marais (5Collaborator)

   Stefan Green (Collaborator)

   Linda Jahnke (16No Role Selected)

   Norman Pace (Collaborator)

   Mitchell Schulte (Collaborator)

   John Spear (Collaborator)

   Roger Summons (Collaborator)

   Bo Thamdrup (Collaborator)

   Summary

   Our work examines the microbiology and geochemistry of microbial ecosystems on Earth in order to better understand the production of “biosignatures” – chemical or physical features or patterns that can only have been formed by the activities of life. More specifically, in photosynthetic (light-eating) microbial mats, we examine the factors that control the formation of biosignature gases (such as could be seen by telescope in the atmospheres of planets orbiting other stars) and isotopic and morphological features that could be preserved in the rock record (such as could be examined by rovers on Mars). Additionally, we study the formation of morphological and mineral signatures in chemotrophic (chemical-eating) systems that have no direct access to light or the products of photosynthesis. Such systems likely represent the only viable possibility for extant life on modern day Mars or Europa.

   Astrobiology Roadmap Objectives:

   • Objective 2.1: Mars exploration
   • Objective 4.1: Earth's early biosphere
   • Objective 5.1: Environment-dependent, molecular evolution in microorganisms
   • Objective 5.2: Co-evolution of microbial communities
   • Objective 6.1: Environmental changes and the cycling of elements by the biota, communities, and ecosystems
   • Objective 7.1: Biosignatures to be sought in Solar System materials
   • Objective 7.2: Biosignatures to be sought in nearby planetary systems

   Project Progress

   Photosynthetic systems: Work has focused on characterizing the role of sulfate concentration, sulfur cycling, and sulfate mineralization in production and preservation of volatile and non-volatile biosignatures in microbial mat ecosystems. We are presently analyzing the results of a just-completed year-long incubation experiment to examine the effects of variable sulfate levels (including Archaean ocean levels) on sulfide isotopes as signatures of biological sulfur-cycling activity. This work will characterize a broader range of sulfur isotopes and sulfur species at considerably finer spatial resolution than has thus far been achieved in comparable systems. Further work has examined the templating, by biofilms, of unique morphology during sulfate mineral formation (as may have characterized the last stages of surface water availability on Mars). More specifically, biofilms have been found to impart distinctive textures and induce unique crystallographic aspect ratios, such as enlarged {110} prisms and shortening on the [001] axis, during gypsum mineral formation. Additionally, biologically-induced accessory phases (native sulfur, Ca-carbonate and celestite) have been found in syngenetic and replacive relationships with gypsum phases.

   
   

   Ames NAI team member Tori Hoehler organized and guest edited a special "Follow the Energy" issue of /Astrobiology/. The issue emphasizes life's dependence on energy as the basis for a novel and quantitative approach to habitability, biosignatures, and other research themes in astrobiology. (Image Credit: Cheryse Triano / Tori Hoehler)

   Chemosynthetic systems: Work has focused on characterizing the energetic dimension of habitability as specifically applicable to water-rock reactions in the terrestrial and Martian subsurface. Theoretical work in this area has served to develop an energy balance concept of habitability, which provides a framework for quantifying habitability (as volumetrically or areally normalized biomass density) as a function of physical and chemical environment. This work was published in the journal Astrobiology during the past year. We have worked to apply this concept with the goal of characterizing and quantifying habitability in the context of robotic exploration of Mars surface deposits. Specifically, we are working as part of the Carnegie-led AMASE expedition to assess habitability using MSL flight instrumentation in Mars-analog settings. Our work will define habitability through application of the energy balance criterion to mineralogical indicators of past physical and chemical conditions. Results of this work are in press at Astrobiology. We are further applying the energy balance approach to consider the habitability of the present-day Martian subsurface, through development of cell-scale numerical reaction-transport models that calculate energy balance and habitability in fluid conditions that would develop via serpentinization processes. Results were recently presented at the 2008 Goldschmidt Conference.

   
   

   Photosynthetic bacteria living within actively mineralizing gypsum crusts. The Ames team studied organic and mineral biomarker dynamics in sulfate evaporite environments that may serve as analogs to sites recently explored on Mars. This image formed part of an astrobiology exhibit at the California Academy of Sciences, in a segment that introduced the concept of endolithic (rock-hosted) life. (Image credit: Niko Finke)

   Mission Involvement

   MER, MRO, MSL, MSR

   This investigation supports Mars science in several respects. Our work to understand habitability and biosignature formation in chemosynthetic systems will ultimately support the assessment of habitability by mineralogical means (the principal means presented by planned instrumentation on these missions), with respect both to preserved rocks and, potentially, the modern subsurface. It will also aid in assessing the biosignature preservation potential of rock types that may be encountered during landed Mars exploration. Lastly, it seeks to examine the mechanisms of production and degradation of molecular biosignatures in sulfate-rich hypersaline evaporitic conditions as a direct basis for interpreting any organic materials that may be found during exploration of comparable settings (e.g., Meridiani Planum) on Mars.

   Future Europa Missions

   Our work to define energy-based criteria for habitability will aid in the development of conceptual models that link geophysical and observational constraints to the putative habitability of a Europan ocean.

   TPF/Darwin

   Our work in photosynthetic systems is designed to directly understand the means by which biology transforms stellar energy into distinguishing atmospheric biosignatures. This work would directly support the interpretation of exoplanet atmosphere composition, with an emphasis on life detection.

   Field Expeditions

   Name

   Baja September 2007

   Dates

   September 2007 - September 2007

   Location

   N 27 degrees 40 minutes W 113 degrees 55 minutes

   Description

   Focus on characterization of microbial communities, geochemical cycling, and biomarker dynamics in a high-sulfate evaporitic system.

   Name

   Artic Mars Analog Svalbard Expedition

   Dates

   August 2007 - August 2007

   Location

   77-80 degrees N 18 degrees E

   Description

   Field testing of CheMin in Mars-Analog setting; mapping mineralogical data to habitability in preparation for MSL 2009.

   Cross-Team Collaborations

   Work on both the photosynthetic and chemosynthetic systems aspects of this work have been conducted in conjunction with members of the Colorado NAI team. Research on biomarker formation/degradation in gypsum-hosted endolithic communities in Baja, California, is being coordinated with an effort on the part of Ames Research Center collaborator and Colorado University team member John Spear to do an exhaustive characterization of microbial diversity within those communities. Work in modeling the energetic habitability of hydrothermal systems is being conducted in conjunction with Tom McCollom of the Colorado team.

   In collaboration with members of the Carnegie Institute of Washington team (A. Steele, M. Fogel, and others), Ames team members Blake, Treiman, and Hoehler are engaged in MSL testbed activities and mineralogy studies relevant to Mars exploration in Spitzbergen, Norwegian Arctic. This effort has resulted in successful deployment and operation of CheMin (an instrument that will fly on MSL09) in a geologically diverse field setting, with a paper submitted on this work.

Publications

Bertaux, J.L., Carr, M., Des Marais, D.J. & Gaidos, E.  (2007).  Conversations on the habitability of worlds: the importance of volatiles.  Space Science Reviews, 129(1-3):123-165.

Blake, D., Sarrazin, P., Vaniman, D., Bish, D., Chipera, S., Farmer, J., Des Marais, D.J., Treiman, A., Ming, D. & Morris, D.  (2008).  Mineralogy: The key to habitability for Mars astrobiological studies [Abstract]. Astrobiology Science Conference 2008, April 14-17 2008, Santa Clara, CA.  Astrobiology, 8(2):432.

Bradley, A.S., Hayes, J.M. & Summons, R.E.  (In Review, 2008).  Extraordinary 13C enrichment of diether lipids at the Lost City Hydrothermal Field suggests a carbon-limited ecosystem.  Geochimica et Cosmochimica Acta.

Bradley, A.S., Marx, C.J. & Summons, R.E.  (2007).  Assessing the role of sterol methyltransferase homologues in the methylhopanoid synthesis pathway of Methylobacterium extorquens AM-1. (Abstract).  Organic Geochemistry.

Buckley, D.H., Baumgartner, L.K. & Visscher, P.T.  (2008).  Vertical distribution of methane metabolism in microbial mats of the Great Sippewissett Salt Marsh.  Environmental Microbiology, 10:967-977.

Cardace, D. & Hoehler, T.M.  (2008).  Serpentinizing Fluids Craft Microbial Habitat: Using Geochemistry and Thermodynamics to Identify Metabolic Niches in the Subsurface [Abstract].  Sixth International Conference on Serpentine Ecology, June 15-19, 2008. Final Program, Abs. # 003:14.

Castenholz, R.W. & McDermott, T.R.  (In Press, 2008).  The Cyanidiales: Ecology, Biodiversity, And BiogeographY, In: J. Seckbach (ed.) Red Algae in the Genomics Age. Springer-Verlag.

Des Marais, D.  (2008).  Photosynthetic microbial mats: today, early Earth, (early Mars?). Spring AGU Meeting, Ft. Lauderdale, FL, May 2008. [Abstract].

Des Marais, D.J.  (2007).  Astrobiological exploration of the surface of Mars.  Gravitational and Space Biology, 21(1):2.

Des Marais, D.J.  (2007).  Assessing the potential for ancient habitable environments in Gusev crater, Mars.  Seventh International Conference on Mars, Pasadena, CA, July 9-13, 2007:54.

Des Marais, D.J.  (2008).  Exploring for photosynthesis in deep time and space.  Goldschmidt Conference 2008, Vancouver, B.C., Canada, July 2008. [Abstract].

Des Marais, D.J. & , A.  (2007).  Assessing the potential for ancient habitable environments in Gusev Crater, Mars. AGU Conference, San Francisco, December 10-14, 2007. Abstract No. P23A-1096.

Des Marais, D.J. & , A.  (2007).  Mars Exploration Rovers and water. Bioastronomy 2007, San Juan, Puerto Rico, July 16-20, 2007.

Des Marais, D.J. & Athena_Science_Team, D.J.  (2008).  MER Spirit assessed potential ancient habitable environments in Gusev Crater, Mars [Abstract] Astrobiology Science Conference 2008, April 14-17 2008, Santa Clara, CA.  Astrobiology, 8(2):433.

Des Marais, D.J., Borg, L., Beaty, D.W. & MEPAG_ND-SAG_TEAM, D.W.  (2008).  Possible Science Priorities for Mars Sample Return [Abstract] Lunar and Planetary Science XXXIX 10-14 March 2008, League City, TX (Abstract No. 4037).

Des Marais, D.J., Jakosky, B.M. & Hynek, B.M.  (2008).  Astrobiological implications of Mars surface composition and properties..  In: J.A. Bell (Ed.).  The Martian Surface: Composition, Mineralogy and Physical Properties (pp. 599-623).  Cambridge Planetary Science.

Ehlmann, B.L., Mustard, J.F., Fassett, C.I., Schon, S.C., Head, J.W., Des Marais, D.J., Grant, J.A., Murchie, S.L. & , C.-T.  (2008).  Clay minerals in delta deposits and organic preservation potential on Mars.  Nature Geosciences, 1(6):355-358.

Fishbaugh, K.E., Lognonné, P., Raulin, F., Des Marais, D.J. & Korablev, O.  (2007).  Geology and Habitability of Terrestrial Planets, Space Science Series of ISSI.  Springer.

Foster, J.S., Green, S.J., Hetherington, K. & Bebout, L.  (2007).  Cyanobacterial diversity in marine stromatolites: role of multiple ecotypes. (Abstract).  Cyanobacterial Molecular Workshop, Delvan, WI.

Foster, J.S., Green, S.J., Hetherington, K., Reid, R.P. & Bebout, L.  (2008).  Evidence for Redundant Cyanobacterial Ecotypes in the Stromatolites of Highborne Cay, Bahamas (Abstract).  Astrobiology Science Conference, Santa Clara, CA.  Astrobiology, 8(2):380.

Green, S.J., Blackford, C., Bucki, P., Jahnke, L.L. & Prufert-Bebout, L.  (2008).  A Salinity and Sulfate Manipulation of Hypersaline Microbial Mats Reveals Stasis in the Cyanobacterial Community Structure.  ISME Journal, 2:457-470.

Green, S.J., Blake, D.F. & Blank, J.G.  (2008).  A novel microbial mat developing in ophiolite-hosted moderately alkaline spring water (Abstract).  Southeastern Ecology and Evolution Conference, Florida State University (Tallahassee, FL).

Green, S.J., Blake, D.F. & Blank, J.G.  (2008).  Microbial Community Composition and Diversity in Unusual, Ophiolite-Hosted Alkaline Waters (Abstract).  108th General Meeting of the American Society for Microbiology, Boston, MA.

Green, S.J., Blake, D.F. & Blank, J.G.  (2008).  A Novel Microbial Mat Developing in Ophiolite-hosted Moderately Alkaline Springwater (Abstract).  Astrobiology Science Conference, Santa Clara, CA.  Astrobiology, 8(2):380.

Hausrath, E.M., Treiman, A.H., Bish, D.L., Blake, D., Sarrazin, P., Hoehler, T., Vicenzi, E., Midtkandl, I., Steele, A. & Brantley, S.L.  (In Press, 2008).  Short and long-term olivine weathering in Svalbard, and implications for Mars.  Astrobiology.

Hoehler, T.M.  (2007).  An energy balance concept of habitability.  Astrobiology, 7:824-838.

Hoehler, T.M.  (2007).  Microbial minimum free energy requirements in natural systems [Abstract].  First International Workshop on Microbial Life under Extreme Energy Limitation.

Hoehler, T.M.  (2008).  Energy as a constraint on habitability [Abstract].  2008 Astrobiology Science Conference.  Astrobiology, 8.

Hoehler, T.M., Alperin, M.J., McCollom, T.M. & Rogers, K.L.  (2008).  Habitability of serpentinizing systems for methanogenic microorganisms: an energy balance model [Abstract].  2008 Goldschmidt Conference.

Hoehler, T.M., Amend, J.P. & Shock, E.L.  (2007).  A ‘follow the energy’ approach to astrobiology.  Astrobiology, 7:819-823.

Jahnke, L.L., Orphan, V.J., Embaye, T., Turk, K.A., Kubo, M., Summons, R.E. & Des Marais, D.J.  (2008).  Lipid biomarker and phylogenetic analyses to reveal archaeal biodiversity and distribution in hypersaline microbial mat and underlying sediment.  Geobiology, 6:394-410.

Kuebler, K., Jolliff, B.L. & Treiman, A.  (In Press, 2008).  Aqueous alteration of olivine in Martian meteorites at microscopic scales. [Abstract].  Geological Society of America Ann. Mtg.,.

Lehr, C.R., Frank, S.D., Norris, T.B., D’Imperio, S., Kalinin, A.V., Toplin, J.A., Castenholz, R.W. & McDermott, T.R.  (2007).  Cyanidia (Cyanidiales) Population Diversity And Dynamics In An Acid-Sulfate-Chloride Spring In Yellowstone National Park.  J. Phycol., 43:3-14.

Londry, K.L., Dawson, K.G., Grover, H.D., Summons, R.E. & Bradley, A.S.  (2008).  Stable carbon isotope fractionation between substrates and products of Methanosarcina barkeri.  Organic Geochemistry, 39:608-621.

Meyer-Dombard, D., Dibbell, A., Bradley, A.S., Shock, E.L. & Summons, R.E.  (2007).  Microbial Diversity and SIP investigations of streamer biofilm communities in Yellowstone National Park.  (Abstract).  Geochimica et Cosmochimica Acta, 71(15):A661.

Orphan, V.J., Jahnke, L.L., Embaye, T., Turk, K.A., Pernthaler, A., Summons, R.E. & Des Marais, D.J.  (2008).  Characterization and spatial distribution of methanogens and methanogenic biosignatures in hypersaline microbial mats of Baja California.  Geobiology, 6:376-393.

Smith, J.M., Green, S.J., Kelley, C.A., Prufert-Bebout, L. & Bebout, B.M.  (2008).  Shifts in methanogen community structure and function associated with long-term manipulation of sulfate and salinity in a hypersaline microbial mat.  Environmental Microbiology, 10(2):386-394.

Squyres, S.W., Arvidson, R.E., Ruff, S., Gellert, R., Morris, R.V., Ming, D.W., Crumpler, L., Farmer, J.D., Des Marais, D.J., Yen, A., McLennan, S.M., Calvin, W., Bell, J.F., Clark, B.C., Wang, A., McCoy, T.J., Schmidt, M.E. & DeSouza_Jr, P.A.  (2008).  Detection of silica-rich deposits on Mars.  Science, 320(5879):1063-1067.

Stephens, E.A., Braissant, O. & Visscher, P.T.  (In Review, 2008).  The Role of Spirochetes in Salt Marsh Microbial Mat Geochemistry and Implications for the Fossil Record.  Carnets de Géologie (Notebooks in Geology).

Stuart, J., Green, S.J. & Blank, J.G.  (2008).  Dolomite Precipitation Experiments with Microbes and Alkaline Waters from the Del Puerto Ophiolite, California Coast Range USA (Abstract).  Astrobiology Science Conference, Santa Clara, CA.  Astrobiology, 8(2):415.

Talbot, H.M., Summons, R..E., Jahnke, L.L., Cockell, C.S., Rohmer, M. & Farrimond, P.  (2008).  Cyanobacterial bacteriohopanepolyol signatures from cultures and natural environmental settings.  Organic Geochemistry, 39:232-263.

Toplin, J.A., Norris, T.B., Lehr, C.R., McDermott, T.R. & Castenholz, R.W.  (2008).  Biogeographic and Phylogenetic Diversity of Thermoacidophilic Cyanidiales in Yellowstone National Park, Japan, and New Zealand.  Applied And Environmental Microbiology, 74(9):2822-2833.

Treiman, A.H.  (2008).  Fault-trace ridges, Valles Marineris, Mars: Evidence for large-scale fault-controlled paleo-groundwater flow.  Nature Geosciences, 1:doi: 10.1038/ngeo131.

Treiman, A.H. & Steele, A.  (In Press, 2008).  Jarosite, hematite, and smectite in the aqueous alteration material of the Yamato-000593/794 nakhlite (Martian meteorite). [Abstract].  Geological Society of America Ann. Mtg.,.

Turk, K., Green, S.J., Jahnke, L., Kubo, M., Parenteau, M.N., Vogel, M. & Des Marais, D.  (2008).  Phylogenetic Analysis of Microbial Communities from Gypsum Precipitating Environments (Abstract).  Astrobiology Science Conference, Santa Clara, CA.  Astrobiology, 8(2):383.

Turk, K.A., Jahnke, L.L., Green, S.J., Kubo, M.D., Vogel, M.B. & Des Marais, D.J.  (2007).  Lipid and Phylogenetic Analysis of a Gypsum-hosted Endoevaporitic Microbial Community (Abstract).  2007 AGU Fall Meeting, San Francisco, CA.  Abstracts Fall meeting American Geophysical Union:B41A-0031.

Vogel, M.B., Des Marais, D.J. & Jahnke, L.L.  (2007).  Biosignatures in modern sulfates: texture, composition and depositional environments of gypsum deposits at Guerrero Negro, Baja, Mexico.  (Abstract).  NASA Astrobiology Institute Field Workshop.  Biosignatures in Ancient Rocks (BAR). Sudbury, Ontario, Canada, September 18-20, 2007.

Vogel, M.B., Des Marais, D.J., Jahnke, L.L., Turk, K. & Kubo, M.  (2007).  Biosignatures in modern sulfates: texture, composition and depositional environments of gypsum deposits at Guerrero Negro, Baja Mexico [Abstract].  Abstracts Fall meeting American Geophysical Union, 88(52):B31D-0622.

Vogel, M.B., Des Marais, D.J., Jahnke, L.L., Turk, K.A. & Kubo, M.D.Y  (2008).  Lipid Biomarkers from Subaqueous and Subsedimentary Gypsum Deposits of Guerrero Negro, Mexico: Examining Discretization and Layering of Pigmented Endoevaporitic Microbial Communities.  Astrobiology, 8(2):330.