RESEARCHERS DISCOVERS LIFE BUILT WITH TOXIC CHEMICAL
12.02.10
NASA-funded astrobiology research has changed the fundamental knowledge about what comprises all known life on Earth.
Researchers conducting tests in the harsh environment of Mono Lake in California have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism substitutes arsenic for phosphorus in its cell components.
This finding of an alternative biochemistry makeup will alter biology textbooks and expand the scope of the search for life beyond Earth. The research is published in this week's edition of Science Express.
TRT: 4:14
Supers: NASA
Felisa Wolfe-Simon, NASA Astrobiology Research Fellow, U.S.G.S.
Pamela Conrad, Astrobiologist, NASA Goddard SFC
Center Contact: Cathy Weselby, 650-604-2791
HQ Contact: Dwayne Brown, 202-358-1726
For more info: www.nasa.gov
Felisa Wolfe-Simon, NASA Astrobiology Research Fellow, U.S.G.S.
Cut 1 - (00:26) -“I’d like to introduce to you today the bacterium GFAJ-1, -1. These are not little potatoes. They are microbes that scientists lovingly call little bugs, but they’re not bugs, their microbes, and this is a bacterium that although looks ordinary, like a type of micrograph many of us may have seen in different places, but it’s doing something extraordinary”
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Felisa Wolfe-Simon, NASA Astrobiology Research Fellow, U.S.G.S.
Cut 2 - (00:34) - “I’ve led a team that has discovered a microbe that can substitute arsenic for phosphorus in its major biomolecules, but let me step back for a minute. All life that we know of requires carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur and it uses those six elements in some of the critical pieces I think we’re all familiar with including: DNA and RNA or the information technology of the cell, the proteins which are the molecular machines and the lipids which separate you from everything else. And so, we‘ve discovered an organism which can substitute one element for another."
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Felisa Wolfe-Simon, NASA Astrobiology Research Fellow, U.S.G.S.
Cut 3 - (00:37) – “We took that mud and we gave it a laboratory environment that was rich in everything else it needed, sugar, vitamins, not that bad for us and we added no phosphorus, and had very high doses of arsenic, it was a double whammy for us. This is not an experiment that most people might run, but it was driven by question: is there a microbe on earth that could substitute arsenic for phosphorus in its basic biomolecular constituents. And so, what did we find? We found that not only did this molecule cope or deal with the toxicity, you might say, but it grew and it thrived.”
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Felisa Wolfe-Simon, NASA Astrobiology Research Fellow, U.S.G.S.
Cut 4 - (00:26) -“What I’ve presented to you today is a microbe doing something different than life as we know it. I was taught as a biochemist that all life on earth, all life we know of, to harken back to the pale blue dot ideas of Carl Sagan; all life we know of is here so far. And, if there is an organism on earth doing something different, we’ve cracked open the door for what’s possible for life elsewhere in the universe.”
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Pamela Conrad, Astrobiologist, NASA Goddard Space Flight Center
Cut 5 - (00:10) -“I find this result delightful because it makes me have to expand my notion of what environmental constituents might enable habitability.
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Pamela Conrad, Astrobiologist, NASA Goddard Space Flight Center
Cut 6 - (00:11) – “What is really interesting about this result is if you can make a bio-molecule that has substitutions in it, the properties have to change as a function of new constituents.”
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Pamela Conrad, Astrobiologist, NASA Goddard Space Flight Center
Cut 7 - (00:37) -“With respect to space exploration, this is a very interesting result again because the implication is that we still don’t know everything there is to know about what would make a habitable environment on another planet, or a satellite of another planet; we have to increasingly broaden our perspective. So, perhaps arsenic is not an essential component for habitability or for life, but it may be one that can be tolerated , and that opens up our perspective to try to understand to find out what other components might be tolerated or in fact even essential that we presently haven’t thought of.”
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