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Project Progress

Year 8 focused on three activities.

1. We conducted fieldwork at four sites in extreme environments. This consisted of field trips to the Bolivian Andes as part of the SETI NAI team led by Nathalie Cabrol of the SETI Institute. The idea was that 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 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, undergoing testing for desiccation and UV radiation resistance. 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 indicate that these organisms are also resistant to hard radiation. We are now refining our estimates 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). In preparation for the EXPOSE flight, we are in the midst of conducting a bio-compatibility study in the ground simulation facility at the DLR in Cologne, Germany. Naked DNA was exposed as a UV dosimeter, and UV readings were taken with broadband sensors, and cross-calibrated with Eldonet readings. The work on one of the lagoons, Laguna Colorado, was presented at AbSciCon in Washington DC. New sites visited this year included Uyuni and a series of lagoons north near La Paz.

   The second field site was a radioactive hotspring, Paralana Springs, in the Flinders Ranges in central Australia. Although we did not visit this site this year, currently collaborator Anitori is working on getting samples into culture and identifying the organisms through DNA sequencing prior to testing for radiation resistance.

   Third was an exploratory field trip to Lassen Volcanic National Park. High temperature sites were surveyed and snow algae were collected to try to get them into culture in the lab.

   Finally, Research Associate Dana 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.

2. 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.
3. We assessed the survival of microbes in meteorites. Collaborator Consolmagno obtained a rock breccia that functions as an analog of meteorites and is determining crack dimensions in collaboration with the Natural History Museum, London. In our lab, Research Associate Rogoff has begun to test whether we can easily get microbes in and out of the breccia. This work is being conducted to prepare for tests of radiation resistance of the organisms located inside meteorites, and to acquire sufficient data to justify our request for actual meteorite samples.