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Project Progress

Low temperature is a predominant environmental characteristic of interstellar space, our solar system, including most of the planets and their satellites, and asteroids and meteors. An understanding of the impact of low temperatures on the responses and evolution of biological organisms is, thus, integral to our knowledge of Astrobiology. The research that we propose will explore multiple aspects of microbial adaptation to low temperatures. One major line of investigation will be to conduct structural and functional genomic and proteomic analyses of bacteria that have been isolated from the Arctic and Antarctic permafrost. What genes and proteins enable the permafrost bacteria to inhabit these subfreezing environments? Do they have specific “freezing tolerance” genes? How is expression of the bacterial genome affected by low temperatures and other conditions that “hitchhiker” bacteria might encounter during travel through space on natural objects or spacecraft? In a second line of investigation, we will directly examine, through “test-tube evolution” experiments, bacterial adaptation to low temperatures. The studies will provide insight into how an organism, with a given complement of genes, can cross niche barriers that are defined by decreasing temperatures. And finally, we will use the information gained to explore the potential development of “signatures” for the presence of life in cold environments including Earth and other bodies such as Mars and Europa.

The proposed studies will provide significant new information relating to multiple NASA astrobiology goals including understanding how life evolves at the molecular and organismal levels; establishing the environmental limits for life; identifying possible signatures for life in other worlds; and understand the responses of terrestrial life to conditions of space and other planets. Additionally, there are significant potential practical applications of the work ranging from the identification of genes that may be used to confer improved environmental stress tolerance in crop plants to the discovery of enzymes uniquely suited to catalysis at low temperature, a characteristic of importance in numerous biotechnology applications.