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Project Reports

• Genome-Genome Integration: Symbiosis, Genetic Assimilation, and Evolutionary Innovation

  Unlike single mutations, genome interactions can catalyze the acquisition of entirely new combinations of functions and drive major evolutionary transitions. Through studies of binary interactions between two species – i.e. a symbiont and its host- we can dissect the mechanisms of genome communication and coevolution. Through a comparative genomic approach, we are deciphering the 'language’ used to establish and maintain intimate associations between bacteria and animal hosts. Our ultimate objective is to understand how such interactions have contributed to organismal complexity and evolutionary novelty.

  ROADMAP OBJECTIVES: 5.1 5.2 6.2

• Expanding the List of Target Stars for Next Generation SETI Searches

  For decades the conventional wisdom considered M dwarf stars unsuitable hosts for habitable planets. We convened an interdisciplinary workshop of thirty scientists to reconsider the issue. They concluded that life could evolve on planets orbiting higher mass M dwarfs. This improves the prospects for finding extraterrestrial life since M dwarfs account for about 75% of all stars. Based on these results, we are preparing a list of more than a million “target” stars for a search for extraterrestrial intelligence (SETI) project.

  ROADMAP OBJECTIVES: 1.1 1.2 4.3 6.2 7.2

• Examination of the Microbial Diversity Found in Ice Cores (Brenchley)

  Our goal is to discover microorganisms surviving in cold or frozen environments and to use this information to understand how different microorganisms survive extreme habitats. Our recent results demonstrated that abundant populations, including many bacteria representing novel taxa, exist frozen in a Greenland glacier ice core for at least 120,000 years. Current isolates are being characterized as new species of ultra-small celled bacteria. This research provides insight into microbial survival in extreme environments that might exist elsewhere in the solar system.

  ROADMAP OBJECTIVES: 2.1 5.1 5.2 5.3 6.1 6.2 7.1

• Microbial Communities and Activities in the Deep Marine Subsurface

  Novel and unexplored microorganisms thrive in deeply buried marine sediments hundreds of meters below the sea bottom. They extend the domain of life into these energy-starved deep sediments and into the underlying ocean crust. These organisms play essential roles in the microbial cycling of carbon in the deep subsurface. We are exploring their biodiversity, their genetic and physiological repertoire, their role in the ocean ecosystem, and their potential as analogs for extraterrestrial life (see Fig. 1)

  ROADMAP OBJECTIVES: 5.1 5.3 6.1 6.2

• Design, Construction and Testing of a Cavity-Ring Down Spectrometer for Determination of the Concentration and Isotopic Composition of Methane

  The recent detection of CH₄ in the Martian atmosphere and observations suggesting that it varies both temporally and spatially argues for dynamic sources and sinks. CH₄ is a gaseous biomarker on Earth that is readily associated with methanogens when its H and C isotopic composition falls within a certain range. It is imperative that a portable instrument be developed that is capable of measuring the C and H isotopic composition of CH₄ at levels comparable to that on Mars with a precision similar to that of an isotope ratio mass spectrometer and that such an instrument be space flight capable. Such an instrument could guide a rover to a site on Mars where emission of biogenic gases is occurring and samples could be collected for Mars sample return.

  ROADMAP OBJECTIVES: 2.1 2.2 3.3 4.1 5.1 5.2 5.3 6.1 6.2 7.1 7.2

• Environmental Genomics Reveals a Single Species Ecosystem Deep Within the Earth.

  The first metagenome sequence from a deep subsurface environment of South Africa has not only described the genetic composition of a new genera/species of sulfate reducing bacteria, Desulforudis Audaxviator, but has also revealed that it is by far the most dominant and most likely the sole resident of its environment. A single species ecosystem has never been reported before and runs counter to the prevalent concept that microorganisms live and evolve as communities of mixed species. Whether this bacterial species occurs in other deep subsurface environments around the world or whether other deep subsurface environments are also occupied by single species remains to be determined.

  ROADMAP OBJECTIVES: 2.1 5.1 5.2 5.3 6.2

• 5. Life in Extreme Environments

  ROADMAP OBJECTIVES: 3.1 5.1 5.3 6.2 7.1

• Interplanetary Pioneers

  The possibility of life traveling from Earth to beyond, and, in general, life traveling from planet to planet, has captured the public’s imagination for a century or more. We are now poised to assess this possibility with experimentation. In this project, we focus on halophiles — organisms that live in high salt environments — as potential Earth life to survive space travel. Thus we have explored high UV and high salt environments, and have flown some of these organisms on European space missions. This year we also began to develop the use of high altitude ballooning to mimic travel beyond the surface of the earth.

  ROADMAP OBJECTIVES: 5.3 6.2

• Genomics of Sulfidic Cave Extremophiles (Supplement to NNA04CC06A)

  We investigated the ecology and evolutionary relationships among extremely acid-loving bacteria and archaea living in biofilms called “snottites” in sulfidic caves in Italy and Mexico. The acid-loving microbes form the base of food chains cut off from the surface, and present rare examples of microbially dominated ecosystems (like ecosystems present for much of earth history and those potentially elsewhere in the universe). The snottites are also important because they help us learn how life adapts to environmental conditions much different from the ones that can be tolerated by our own species (pH 0-1). Future work based on the foundation presented here will reveal how subsurface microorganisms in geographically isolated “geochemical islands” are related to each other and to microorganisms living at the earth’s surface.

  ROADMAP OBJECTIVES: 5.1 5.3 6.2

• 7. Astrobiotechnology

  ROADMAP OBJECTIVES: 2.1 2.2 3.1 3.2 5.3 6.2 7.1

• Identifying Microbial Life at Crustal Rock-Water Interfaces

  We are working to cultivate and characterize microorganisms which directly derive energy from reactions between mafic rocks and water. We are particularly targeting organisms that colonize the surfaces of the rocks during alteration. Thus we are also developing high-resolution chemical measurements capable of detecting reaction fronts and mineral by-products that form over time at the microbe-mineral interface.

  ROADMAP OBJECTIVES: 5.2 5.3 6.1 6.2 7.2

• Mars Forward Contamination Studies Utilizing a Mars Environmental Simulation Chamber

  A variety of microorganisms have been selected for experimental culturing in a Mars environmental simulation chamber. The test organisms are adapted on Earth to desiccation resistance and cold tolerance so they are suitable for exposure to simulated surface conditions on Mars. The test chamber is capable of reproducing temperatures, solar radiation, and atmospheric conditions inferred for Mars. Results from these tests will provide critical information for the design and engineering of sampling and caching equipment on a future mission to sample rocks and sediments on Mars and return those samples to Earth for laboratory study.

  ROADMAP OBJECTIVES: 2.1 3.2 3.3 5.1 5.2 5.3 6.1 6.2 7.1

• The High Lakes Project (HLP)

  The High Lakes Project is a multi-disciplinary astrobiological investigation studying high-altitude lakes between 4,200 m and 5,916 m elevation in the Central Andes of Bolivia and Chile. Its primary objective is to understand the impact of increased environmental stress on lake habitats and their evolution during rapid climate change as an analogy to early Mars. Their unique geophysical environment and mostly uncharted ecosystems have added new objectives to the project, including the assessment of the impact of low ozone/high solar irradiance in non-polar aquatic environments, the documentation of poorly known ecosystems, and the quantification of the impact of climate change on lake environment and ecosystem.
  Data from 2003 to 2007 show that solar irradiance is 165% that of sea level with instantaneous UV-B flux reaching 17W/m2. Short UV wavelengths (260-270 nm) were recorded and peaked at 14.6 mW/m2. High solar irradiance occurs in an atmosphere permanently depleted in ozone falling below ozone hole definition for 33-36 days and between 30-35% depletion the rest of the year. The impact of strong UV-B and UV erythemally-weighted daily dose on life is compounded by broad daily temperature variations with sudden and sharp fluctuations. Lake habitat chemistry is highly dynamical with notable changes in yearly ion concentrations and pH resulting from low and variable yearly precipitation. The year-round combination of environmental variables define these lakes as end-members. In such an environment, they host surprisingly abundant and diverse ecosystems including a significant fraction of previously undescribed species of zooplankton, cyanobacterial, and bacterial populations.

  ROADMAP OBJECTIVES: 1.1 2.1 4.1 4.3 5.1 5.2 5.3 6.1 6.2 7.1

• The Virtual Planetary Laboratory – The Life Modules – Photosynthesis

  Photosynthesis provides the foundation for nearly all life on our planet and produces unique life signs — atmospheric oxygen and pigment colors — that are detectable from space at the global scale. This project seeks to determine the adapative rules for why photosynthetic pigments absorb particular wavelengths of light, and to quantify what is the long wavelength limit for oxygenic and also anoxygenic photosynthesis. This work will allow us to predict the plausible spectral properties and detectable properties of photosynthesis on other planets, especially those orbiting M stars, where longer wavelengths of light dominate the planetary surface radiation.

  ROADMAP OBJECTIVES: 5.1 6.1 6.2 7.2

• Radiolytic Oxidation of Sulfide Minerals as a Source of Sulfate and Hydrogen to Sustain Microbial Metabolism

  Microbial ecosystems have been discovered in crustal environments up to 2.8 kilometers below the surface of Earth. Life in this extreme environment apapears to be sustained by high concentrations of dissolved sulfate and hydrogen. Splitting of water molecules by radiation from uranium can produce oxidation gradients that result in simple ionic products usable for maintenance and growth of microbial organisms. A set of experiments exposing water and common sulfide minerals to radiation in a laboratory reactor were conducted to test this hypothesis.

  ROADMAP OBJECTIVES: 1.1 2.1 3.3 4.1 5.1 5.3 6.2

• Planet Formation and Dynamical Modeling

  ROADMAP OBJECTIVES: 1.1 3.1 6.2

• The Diversity of the Original Prebiotic Soup: Re-Analyzing the Original Miller-Urey Spark Discharge Experiments

  Recently obtained samples from some of the original Stanley Miller spark discharge experiments have been reanalyzed using High Pressure Liquid Chromatography-Flame Detection and Liquid Chromatography-Flame Detection/Time of Flight-Mass Spectrometry in order to identify lesser constituents that would have been undetectable by analytical techniques 50 years ago. Results show the presence of several isoforms of aminobutyric acid, as well as several serine species, isomers of threonine, isovaline, valine, phenylalanine, ornithine, adipic acid, ethanolamine and other methylated and hydroxylated amino acids. Diversity and yield increased in experiments utilizing an aspirating device to increase the gas flow rates; this could be applied as a simulation of prebiotic chemistry during a volcanic eruption. The variety of products formed in these experiments is significantly greater than previously published and mimic the assortment of compounds detected in Murchison and CM meteorites.

  ROADMAP OBJECTIVES: 2.1 3.1 3.2 3.4 4.1 4.2 5.1 6.2 7.1 7.2

• Icelandic Subglacial Lakes

  This project is describing the microbial community inhabiting the water column of a subglacial volcanic lake in Iceland. These systems are potential analogs for habitats on ice-covered worlds such as the outer planet satellites, and Mars.

  ROADMAP OBJECTIVES: 2.1 4.1 5.3 6.2

• Sediment-Buried Basement Deep Biosphere

  There is growing evidence that a substantial subseafloor biosphere extends throughout the immense volume of aging basement (basaltic rock) of the ocean crust. Since most ocean basement rock is buried under thick, impermeable layers of sediment, the fluids circulating within the underlying ocean basement are usually inaccessible for direct studies. Circulation Obviation Retrofit Kit (CORK) observatories affixed to Integrated Ocean Drilling Program (IODP) boreholes offer an unprecedented opportunity to study biogeochemical properties and microbial diversity in circulating fluids from deep ocean basement. UH-NAI post doctoral fellows (e.g., Brian Glazer, Andrew Boal)

  ROADMAP OBJECTIVES: 1.1 3.3 4.1 5.1 5.2 5.3 6.1 6.2