NASA's Alien Life News: Here's the Real Story from Science Magazine
The Science Press Package Summary:
You may have seen Internet speculation on Dec. 1, 2010 about a NASA announcement related to the search for extra-terrestrial life. The online rumors weren't quite right. But from a science perspective, a paper being published Dec. 2 by the journal Science does describe a pretty amazing microbe. Scientists have discovered bacteria that can live and grow entirely off poison, arsenic (rather than the usual phosphate).
Found in California's Mono Lake, the salt-loving bacteria, a member of the Halomonadaceae family of proteobacteria, may support NASA's astrobiology program because it suggests that the requirements for life's basic building blocks may be more flexible than we thought. In the lab, the researchers grew the bacteria in Petri dishes in which phosphate salt was gradually replaced by arsenic, until the bacteria could grow without needing phosphate, an essential building block for various macromolecules present in all cells, including nucleic acids, lipids and proteins. Using radio-tracers, the team closely followed the path of arsenic in the bacteria; from the chemical's uptake to its incorporation into various cellular components. Arsenic had completely replaced phosphate in the molecules of the bacteria, right down its DNA. The work by Felisa Wolfe-Simon and colleagues will be available to Science subscribers soon at www.sciencemag.org.
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