The Mono Lake Natron is one who is both a very alkaline and very salty, in Mono County in the central-eastern part of California. He is a endorheic basin on the western edge of the Great Basin in the eastern flank of the Sierra Nevada. Due to the harsh environmental conditions, animals and plants have adapted and salinity both at the high pH endure, why become an ecosystem of very few adapted species at very high number of individuals has, that's for some bird species of importance.The Mono Lake in eastern California is a headstrong sea: Its water is salty and arsenic, porous tufa towers stand on the shore. A cozy place is different. Now, researchers have particularly unusual creatures on the muddy bottom of the lake discovered
NASA scientists report in the journal "Science" that they have fished microorganisms from the sea, which seem to contradict all that has been accumulated biosciences. For these organisms, which have been assigned to receive only the abbreviation GFAJ-1 eat, arsenic, and not die when they add the poison in her body.
Felisa Wolfe-Simon of the NASA Astrobiology Institute and her team are samples from the lake sediments are removed. In it they found proteobacteria, more precisely, the tribe GFAJ-1, which belongs to the family of Halomonadaceae. These have allowed the researchers to then NASA gebracht.In laboratory petri dishes grow the single-celled organisms and fed them with phosphorus and arsenate, the salts of arsenic acid. They gradually increased the concentrations of arsenic salts.Surprisingly, endured the GFAJ-1 cells to toxic food, yes, she lived at the end of it even exclusively. They built that in itself toxic element even in their genome. "This reminds us that life as we know it can be much more flexible than we normally assume or imagine," said Wolfe-Simon.
The researchers sought to trace the unusual metabolism of the microorganisms accurately. They discovered that the arsenic compounds were always built into the cells, which are usually phosphorus compounds. Phosphorus and its derivatives were previously considered irreplaceable building blocks of all life - not only carbon, hydrogen, nitrogen, oxygen and sulfur. That arsenic replaces phosphorus, is the fact that both elements are very similar in their atomic structure. In the periodic system, they stand directly under each other. In nature, phosphorus occurs mostly as phosphate before - which behaves chemically and physically very similar to arsenate. And this similarity is usually also the key to the toxicity of arsenic: Because it actually displaces the essential phosphate from the body, thus preventing the previously known organisms that live their cells.
But the Mono Lake Halomonadaceae seem to work differently than the rest, previously analyzed life on Earth. However, as the researchers stress, arsenic does not love them. They grow and thrive much better, although phosphorus in their environment ist.Dass just a team of NASA researcher Felisa Wolfe-Simon arsenic such bacteria are discovered surprising little. For astrobiologists search on the ground, and not only in space by an unusual life. Especially in extreme places like California's Mono Lake, the chance is very great to find organisms that work differently than the vast majority of life on earth."The replacement of one of the basic organic elements could have far-reaching implications for the evolution and geochemistry have," write researchers.
Since it GFAJ-1 seems able to survive in an environment well, in which there is no phosphate, alien researchers must expand their search range now.
For the discovery of arsenic eaters also change the search strategy for extraterrestrial life. Also on Extraterrestrial Bodies with high concentrations of toxic elements and without phosphorus compounds, it could also give life.
"If something can be done here on Earth as something unexpected, what life can still be what we have not seen yet?" Says Wolfe-Simon. The organisms from the Mono Lake ultimately show that life in the universe is more probable than previously thought.
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