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Project Progress

During this funding period work was continued primarily by Rothschild, Mancinelli and Horneck.

Rothschild developed techniques for measuring deoxyribonucleic acid (DNA) damage both in nature and in the lab. Protocols for measuring the ratio of 8-hydroxyguanosine to guanosine were established; the protocol involved isolation of DNA, digestion and analysis with EC-HPLC, with the high-performance liquid chormotography (HPLC) work conducted in the EPA-certified chemistry lab at NASA Ames. Her group also worked on studying the effect of low levels of radiation and oxidative damage on cells and showed both in the lab and in nature that this can result in a mitogenic effect, meaning that responses to radiation are non-linear and cannot be predicted from simple models. This work will help in the understanding of the ability of organisms to survive in the space environment.

Mancinelli pepared a sample of Lyngbya, as well as more strains of halophiles in the lab at Ames in preparation of simulatin tests at the Deutsche Forschungsanstalt für Luft- und Raumsfahrt (DLR) in Cologne, Germany. Using the space simulation facility at the DLR in Cologne, in Germany, he along with Rettberg and Horneck have completed a series of ground simulation experiments using Lyngbya aestuarii as well as a number of Archaeael halophiles. Using these facilities, they have exposed this organism to vacuum desiccation and ultraviolet (UV) radiation. These experiments reveal that the Lyngbya can survive exposure to both UV radiation and desiccation. We are currently developing methods to quantify their survival. In addition, we have run several organisms through the experiment verification test (EVT) for the Expose facility on the Space Station in prepartion for the ROSE series of experiments.