NASA Astrobiology Institute (NAI)

1. Interplanetary Pioneers

   Project Investigators: Rocco Mancinelli, Lynn Rothschild

   Other Project Members

   Roberto Anitori (Collaborator)

   Gerda Horneck (Collaborator)

   Nadia Krasner (Undergraduate Student)

   Ragnhild Landheim (Research Staff)

   Dana Rogoff (Research Staff)

   Astrobiology Roadmap Objectives:

   • Objective 5: Describe the sequences of causes and effects associated with the development of Earth's early biosphere and the global environment.
   • Objective 6: Define how ecophysiological processes structure microbial communities, influence their adaptation and evolution, and affect their detection on other planets.

   Project Progress

   We conducted fieldwork to four sites in extreme environments. This consisted of field trips to the Bolivian Andes (Dec 2006, Feb 2007. At the altitudes where we sampled (~15,000 feet), the ozone column was substantially reduced, resulting in high levels of UV radiation flux. Additionally, many lagoons exist in the Altiplano with unusual chemistries. As we had suspected, organisms new to science, and possibly highly radiation resistant, appear to grow there. For example, a psychrophilic halophilic bacterium was isolated and is now in pure culture and is undergoing desiccation and UV radiation resistance testing. Other isolates shown to be UV radiation resistant in our lab were exposed to hard radiation at the accelerator facility at Idaho State University. Preliminary data suggests that these organisms are also resistant to hard radiation. We are now refining our assessment of their radiation resistance and comparing them to other organisms known to be extremely radiation resistant (e.g., a sub-species of Halobacterium NRC-1, and Deinococcus radiodurans). Naked DNA was exposed as a UV dosimeter, and UV readings were taken with broadband sensors, and cross calibrated with Eldonet readings. We presented our work on one of the lagoons, Laguna Colorado, at AbSciCon in Washington D.C. New sites visited this year included Uyuni and a series of lagoons north near La Paz. The second field site was a radioactive hot spring, Paralana Springs, in the Flinders Ranges in central Australia. Although we did not visit this site this year, currently collaborator R. Anitori is obtaining cultures from the field samples and identifying the organisms through DNA sequencing prior to testing for radiation resistance. We conducted an exploratory field trip to Lassen Volcanic National Park. We surveyed high temperature sites and collected snow algae to try to get them into culture in the laboratory. Finally, Research Associate D. Rogoff, as part of her Master’s thesis, assessed the community structure and correlated that with pigmentation in the Cargill salt ponds in the South San Francisco Bay. Rogoff successfully defended her thesis at the Tiburon Center, June 13, 2006.

   In preparation for the EXPOSE flight, we are conducting a biocompatibility study in the ground simulation facility at the DLR in Cologne, Germany. Specifically, we performed two experiment verification tests (EVT) this past year at the DLR. These tests were intended to determine whether the design of the flight apparatus and test protocol sequence would encounter problems. In addition, we conducted these tests to determine the compatibility of the various samples with each other and with the flight hardware. We found no compatibility problems among the samples or between the samples and any component of the flight hardware.

   We developed high-throughput assays to detect DNA damage. Previously our lab used an HPLC method that while accurate, required highly purified DNA and was expensive and slow. Through work conducted by Erin Lashnits, formerly an undergraduate and now a graduate student at Stanford, a quicker, high throughput method for detection of direct and indirect DNA damage is available in our lab using fluorescent antibodies.

   
   Figure 1. Laguna Colorada, in the Bolivian Altiplano, is a high altitude (4300 m) hypersaline lake from which our team has isolated radiation resistant organisms. Photo: Lynn Rothschild, July 2007

   
   Figure 2. Laguna Blanca, at over 4000 m in altitude, has provided a high altitude location for solar UV measurements. In this photo, Rothschild is measuring the solar spectrum and its effect on DNA damage. Photo: Joseph Minafra

   
   Figure 3. Rothschild measures solar radiation at Laguna Verde, in the Bolivian Altiplano. At 4332 m in altitude, we have measured very high levels of UV radiation. Photo: Joseph Minafra

   
   Figure 4. Along with extensive outreach activities in YNP, our team has studied the effects of solar radiation on DNA damage. The parking lot at Old Faithful provides an impromptu field site. Photo: Lynn Rothschild.

   Mission Involvement

   EXPOSE (ESA ISS mission)

   Exposure of halophilic microbes to the space environment using the EXPOSE unit on the exterior of the ISS.

   Field Expeditions

   Name

   Yellowstone National Park

   Dates

   8/1/06 - 8/3/06

   Location

   Description

   Name

   Bolivian Altiplano

   Dates

   12/15/06 - 12/24/06

   Location

   67° 46' 53 22° 49' 17

   Description

   To collect organisms that might be highly radiation resistant. To measure UV radiation. To assess natural UV damage to organisms.

   Name

   Bolivian Altiplano

   Dates

   2/06 - 2/06

   Location

   67° 46' 53 22° 49' 17

   Description

   To collect organisms that might be highly radiation resistant. To measure UV radiation. To assess natural UV damage to organisms.

   Name

   Cargill Salt Ponds

   Dates

   Summer 2006 - N/A

   Location

   W 122° N 37°

   Description

   To collect organisms that might be highly radiation resistant; to correlate community composition with pigmentation

   Name

   Paralana Springs

   Dates

   2/4/07 - 2/9/07

   Location

   E139°, 26', 26.9 S30°, 10', 39.8

   Description

   To collect organisms that might be highly radiation resistant

Publications

Rothschild, L.J.  (2006).  Extremophiles: defining the envelope for the search for life in the universe.  In: R.E. Pudritz, P. Higgs & J. Stone (Eds.).  Planetary Systems and the Origins of Life.  Cambridge University Press.

Rothschild, L.J.  (2006).  The role of Emergence in biology..  In: P. Clayton & P. Davies (Eds.).  The Reemergence of Emergence (pp. 151-165.).  Oxford University Press.