nai

Project Reports

• Describing the Anaerobic Thermophilic Microbial Community: A Metagenomic Strategy

  The ocean is one of the least explored parts of the microbial world, including at deep-sea hydrothermal vents, where the unique geochemistry creates many habitats for microbial and animal communities. These organisms encounter many conditions that we humans consider too extreme- too hot, too toxic, too little oxygen- but microbes seem to find a way and continue to push the limits of life. An impetus for studying life at deep-sea hydrothermal vents is that life may have originated and evolved near hydrothermal systems, and that organisms currently living in these likely analogues of early habitats may still harbor characteristics of early life. In addition, microbes unique to the hydrothermal vents could provide insight into metabolic processes, strategies for growth, and survival of life on solar bodies with a water history, such as Mars and Jupiter’s moon Europa. Our research on diffuse flow vents at deep-sea hydrothermal seamounts provides insight into the diversity, physiology, and genetic potential of these unique microbial communities within the context of their dynamic and complex geochemical habitat.

  ROADMAP OBJECTIVES: 4.1 5.1 5.2

• Amino Acid Preservation in Saline-Lake Sediments and Mars-Simulant Regolith

  Potentially habitable environments on the Martian surface have been identified by orbital spectroscopy and by landed instruments on the Mars Exploration Rovers (MERs). Identification of evaporite mineral assemblages on Mars provides strong evidence for the widespread role of evaporitic water bodies of water in the past. Evaporite minerals may provide enhanced preservation of biomolecules by sequestration of organic constituents into mineral matrices during crystallization. The utilization of amino acids, the building blocks of proteins, as a distinct biosignature that could be extracted from evaporite phases would provide a strong biosignature for life having existed in the past or persisting to the present on Mars.

  ROADMAP OBJECTIVES: 2.1 3.2 5.1 5.3 7.1

• Biosignatures in Chemosynthetic and Photosynthetic Systems

  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.

  ROADMAP OBJECTIVES: 2.1 4.1 5.1 5.2 6.1 7.1 7.2

• 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

• Challenges for Coring Deep Permafrost on Earth and Mars: Drilling Project at High Lake, Nunavut, Canada

  Accessing liquid water environments and searching for life in the subsurface of Mars during future space missions will require drilling through hundreds of meters of permafrost and frozen rock. Many coring expeditions with the goal of acquiring uncontaminated cores for microbial studies have been performed on Earth, but none in deep permafrost, hard rock terranes. The goal of this project was to determine the requirements for obtaining permafrost core samples that are useful for microbial analyses and to acquire experience in coring through permafrost into the underlying liquid water, fractured rock system at High Lake, Nunavut, Canada.

  ROADMAP OBJECTIVES: 2.1 5.1 7.1

• Modeling Early Earth Environments

  In this project, scientists from different disciplines model the conditions likely to have been found on the Early Earth, prior to 2.3 billion years ago. Specific areas of research include understanding the gases, many biologically produced, and mechanisms that controlled early Earth’s surface temperature, the nature of hazes that shielded the planetary surface from UV and may be responsible for signatures in sulfur isotopes that were left in the rock record, the chemical nature of the Earth’s environment during and after a planet-wide glaciation (a “Snowball event”), the evolution of planetary atmospheres over time due to loss of atmosphere to space, and the use of iron isotopes as a tracer of the oxidative state of the Earth’s ocean over time.

  ROADMAP OBJECTIVES: 1.1 1.2 2.1 4.1 4.2 5.1 5.2 5.3 6.1 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

• 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

• 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

• Earthbound Microbial and Geological Robotic Based Observations for Mars

  This project explores robotic aids to astrobiology in the form of remotely controlled mobile agents with the ability to do human-like tasks in earth and mars like environments. Ethnographic studies are conducted to determine the microgeobiologist and geochemists abilities to use robotic interfaces to collect data and samples in liquid based and liquid-solid interface locations such as seeps, shallow water, surf-zone etc. Several robots are designed and constructed: Robots capable of achieving astrobiologist tasks (in situ testing, sample acquisition) Robots with high mobility to reach harsh environments (amphibious, acidic, saline) Astrobiologist-capable interfaces (long distance teleoperation, multi-modal)

  ROADMAP OBJECTIVES: 2.1 2.2 5.1 5.3

• Ferry Report

  The research addresses how anaerobic Archaea cope with oxidative stress, with the long-term view of how anaerobic life evolved to adapt to rising oxygen levels before, during and after the evolution of oxygenic photosynthesis. The research also addresses ancient enzymes involved in metabolic pathways with a focus on energy conservation in methanogenic Archaea.

  ROADMAP OBJECTIVES: 3.3 4.1 4.2 5.1 6.1

• 5. Life in Extreme Environments

  ROADMAP OBJECTIVES: 3.1 5.1 5.3 6.2 7.1

• DDF: Geomicrobiology of a Unique Ice-Sulfur Spring Ecosystem in the High Arctic

  A glacial, active sulfide spring environment at Borup Fiord Pass on Ellesmere Island in the Canadian High Arctic provides an excellent opportunity to study microbial life at a site that may be an analog to Europa, an ice-covered moon of Jupiter. During the past year we have collected samples from the extensive mats of sulfur-minerals that precipitate in discharge channels to identify the microbial communities hosted in the sulfur-ice, and to cultivate key key organisms mediating the oxidation of H2S to elemental sulfur.

  ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1 7.1 7.2

• Microbial Diversity and Population Structure Studies in the Rio Tinto

  As part of our Microbial diversity and population structure studies in the Rio Tinto, we hope to better understand how environmental conditions such as pH and metal concentrations help shape the underlying microbial community structures in extreme environments that serve as terrestrial analogs for Mars. The iron-based mineralogy found in the Rio Tinto coupled with low pH are two characteristics that tie this extreme environment to Mars. To this end, we have been sampling stations along the river that differ in the concentration and oxidation state of iron and other metals (see http://amarallab.mbl.edu/rt_main/rt.html for more detailed information and photographs of the study locations) and using molecular techniques coupled with physicochemical measurements to investigate microbial diversity in the water column at both spatial and temporal scales. When possible, determination of as many in situ physico-chemical parameters are made on biofilms as well, using microelectrodes available for field measurements. This allows for the correlation of biological diversity information with physicochemical parameters of the river. The outcome of this study will provide a comprehensive view of the microbial ecology of the system, a first step towards establishing an ecological genomics project for the Rio Tinto.

  ROADMAP OBJECTIVES: 3.3 5.1 5.2

• 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

• High Lake Gossan Deposit: An Arctic Analogue for Ancient Martian Surficial Processes?

  The massive sulfide deposit at High Lake is covered by a ~1 meter thick layer of Fe oxides and sulfate minerals. The minerals have formed within the last 8,000 years in the active zone of the permafrost and as such the site provides a good analog to those terranes on Mars that contain similar mineral assemblages, e.g. Terra Meridiana, and may have formed under similar, acidic conditions. The minerals present in the High Lake gossan were characterized by XRD, SEM and Mössbauer.

  ROADMAP OBJECTIVES: 2.1 5.1 5.2 5.3 6.1 7.1

• Functional Genomics of Thioredoxins in Halobacterium Sp. NRC-1

  This project addresses the functions of an ancient protein family in Archaea that occupy extreme environments. Some of these proteins may play roles similar to those of comparable proteins in other living organisms, and thus may tell us about functions that evolved in the last universal common ancestor of life. Others may have evolved as the Archaea began to occupy specialized and often extreme environments. This project also addresses the emergence of proto-metabolic networks that supplied the precursors for the RNA World.

  ROADMAP OBJECTIVES: 3.1 3.2 5.1 5.3

• Planetary-Scale Transition From Abiotic to Biotic Nitrogen Cycle

  Nitrogen is an essential element for life. Understanding the planetary nitrogen cycle is critical to understanding the origin and evolution of life. The earth’s atmosphere is full of nitrogen gas (N2). However, this large pool of nitrogen is unavailable to most of the life on earth except a few microbes capable of “fixing” nitrogen into a form that can be used by other organisms (e.g., NH3, NH4+, NOx, organic-N). Without fixed nitrogen life would not have originated on earth and would most likely not occur on any other planet. The Atacama Desert in Chile is an enigma in that it contains vast nitrate (a type of fixed nitrogen) deposits. Elsewhere on earth, nitrate is either denitrified (transformed into N2 and released back into the atmosphere) through the activity of microorganisms, or is dissolved and leached from the system. Although the Atacama is the driest desert in the world we have shown that lack of water alone cannot account for the lack of nitrogen cycling in this desert. Preliminary data suggest that it may be due to the high oxidation level of the soil in combination with a lack of organic material in the soil.

  ROADMAP OBJECTIVES: 1.1 2.1 3.2 4.1 5.1 5.2 5.3 6.1

• 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

• Microbial Diversity of a Hypersaline Microbial Mat

  The goal of this project is to survey the microbial life that comprises a hypersaline microbial mat at Guerrero Negro, Mexico using culture independent technology (ribosomal and other gene sequences). The results have expanded significantly our knowledge of microbial diversity, bacterial, archaeal and eucaryotic.

  ROADMAP OBJECTIVES: 3.2 3.3 5.1 5.2 5.3 7.2

• Laboratory Microbial Simulations: Astrobiological Signatures

  We aim to use laboratory and field environments to investigate microorganisms and their biogeochemical signatures. We have investigated methanotrophic seeps and deeply-buried marine environments, as well as used laboratory pure-cultures to further our understanding of diverse metabolisms.

  ROADMAP OBJECTIVES: 2.1 4.1 5.1 5.2 5.3 7.1

• 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

• Stromatolites in the Desert: Analogs to Other Worlds

  Field work at Cuatro Ciénegas, Mexico has focused on understanding unique
  structures called microbialites. These are colonies of bacteria that have
  been encased by minerals that have precipated out of the water surrounding
  them. This process have been going on for 2 and a half billion years on
  earth. The work we are doing is using experiments to see how the environment
  can affect the genes in these bacteria to create the microbialites. We do
  this to improve our understanding of how they utilize two very important atoms, carbon and nitrogen. By studying these Earth bacteria we can better understand how microbialites interact with their environemnt, and whether or not microbialites might exist and be detectable in extrasolar environments.

  ROADMAP OBJECTIVES: 5.1 5.2 5.3

• 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

• Microbial Communities in Subpermafrost Saline Fracture Water at the Lupin Au Mine, Nunavut, Canada

  As scientists prepare to search for life in the subsurface of Mars, it is increasingly clear that we have little experience characterizing microbial life in permafrost environments on Earth. Lupin gold mine in Nunavut Territory Canada provides scientists with an opportunity to collect samples of ground water beneath 500 meters of permafrost. These subpermafrost water samples contain extant microbial communities that are dominated by sulfate-reducing bacteria. It remains to be determined how and when this microbial community became established.

  ROADMAP OBJECTIVES: 2.1 5.1 5.2 5.3 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

• Molecular Signatures of Life on the Edge (DDF Project)

  We have investigated the Dead Sea, as a possible analog of early Mars environments — slightly acidic and highly saline. We have used metagenomics, lipid analysis, and amino acid analysis.

  ROADMAP OBJECTIVES: 2.1 5.1 5.2 5.3 7.1

• Diversity and Biogeography of the Unique Tropical Phylum Placozoa

  The following project employed molecular techniques, along with supplemental bioinformatics to: 1) Test whether placozoans are occupying the water column 2) Describe the diversity of placozoans found within sea tables at Kewalo Marine Lab as well as samples from an open water site off Isla Magueyes, Puerto Rico and test whether there is haplotype/clade overlap and 3) Determine if it is possible to capture more of the diversity than previous work by analyzing a more variable region on the mitochondrion

  ROADMAP OBJECTIVES: 4.2 5.1

• 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

• Sulfur Biogeochemistry of the Early Earth

  Sulfur is widespread in surface geochemical systems and is abundant in many rock types. It is present in volcanic gases and marine waters, and has served a key role in geobiological processes since the origin of life. Like other low atomic number elements, sulfur isotope ratios in various compounds usually follow predictable mass-dependent fractionation laws; these different mass-dependent isotope fractionations serve as powerful tracers for igneous, metamorphic, sedimentary, hydrothermal and biological processes. Mass-independent sulfur isotope fractionation is a short-wavelength photolytic effect that occurs in space, as well as in gas-phase reactions in atmospheres transparent to deep penetration by ultraviolet light. Crucial aspects of the chemical evolution of the early atmosphere — and the surface zone as a whole — can be followed by mass-independent sulfur isotopes in Archean metasedimentary rocks. Metabolic styles of organisms in response to global changes in surface redox over geologic time can also be traced with multiple S isotopes.

  We have concluded from our various studies over the last year and before to the very inception of the NAI node at Colorado, that all Archean sulfur minerals previously documented for their 34S/32S compositions warrant a comprehensive re-examination of their 32S, 33S, 34S (and 36S), sulfur isotope systematics.

  ROADMAP OBJECTIVES: 1.1 1.2 4.1 4.2 5.1 5.2 5.3 6.1 7.1 7.2

• Ecology of a Hawaiian Lava Cave Microbial Mat

  We have been studying a microbial biofilm (Figure 1) growing at very low light intensities and high temperature and humidity below the entrance of a lava cave in Kilauea Crater, Hawai’i Volcanoes National Park. (Figure 2)
  The cave presents an oligotrophic environment, but condensation of geothermally heated groundwater that vents at the rear of the cave has promoted the development of a complex microbial community, similar in higher order taxonomic structure to copiotrophic soil environments. Given the existence of lava tubes of similar geologic composition on Mars, geothermal activity there may have allowed the existence, or persistence, of complex microbial communities in similar Martian environments, wherein they would be shielded from the effects of harmful UV radiation.

  ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1

• Mechanisms of Marine Microbial Community Structuring

  The sub-tropical open ocean is an extreme environment that presents the opportunity to examine the factors affecting microbial community structure across a number of environmental gradients. We have developed and utilized a novel assay that allows us to simultaneously determine the taxonomic composition of Archaea, Bacteria and microbial Eucarya in DNA extracted from environmental samples. Samples analyzed represent the epi-, meso- and bathy-pelagic zones of the ocean, which display gradients in temperature, pressure, oxygen content, nutrient content and photosynthetically available radiation.

  ROADMAP OBJECTIVES: 5.1 5.2 5.3 6.1

• 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