Arsenate: Difference between revisions

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In 2008, bacteria were discovered that employ a version of [[photosynthesis]] with arsenites as [[electron donor]]s, producing arsenates (just like ordinary photosynthesis uses water as electron donor, producing molecular oxygen). The researchers conjectured that historically these photosynthesizing organisms produced the arsenates that allowed the arsenate-reducing bacteria to thrive.<ref>[http://www.rsc.org/chemistryworld/News/2008/August/15080802.asp Arsenic-loving bacteria rewrite photosynthesis rules], Chemistry World, 15 August 2008</ref>
 
In 2010, a team at [[NASA]]'s [[NASA Astrobiology Institute|Astrobiology Institute]] cultured samples of arsenic-resistant [[GFAJ-1]] bacteria from [[Mono Lake]], using a medium high in arsenate and low in phosphate concentration. The findings suggest that the bacteria may partially incorporate arsenate in place of phosphate in some biomolecules, including DNA,<ref>[http://www.sciencemag.org/content/early/2010/12/01/science.1197258.short A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus]. Wolfe-Simon F, Blum JS, Kulp TR, Gordon GW, Hoeft SE, Pett-Rdige J, Stolz JF, Webb SM, Weber PK, Davies PCW, Anbar AD, Oremland RS. ''Science'' Express. 02 December 2010.</ref><ref>[http://www.wired.com/wiredscience/2010/12/nasa-finds-arsenic-life-form/ NASA Finds New Arsenic-Based Life Form in California], ''Wired Science'', Dec 2 2010</ref> However, these claims were immediately debated and critiqued in correspondence to the original journal of publication,<ref>Wolfe-Simon, F., Blum, J.S., Kulp, T.R., Gordon, G.W., Hoeft, S.E., Pett-Ridge, J., Stolz, J.F., Webb, S.M., Weber, P.K., Davies, P.C.W., Anbar, A.D. & Oremland, R.S. Response to Comments on "A Bacterium That Can Grow Using Arsenic Instead of Phosphorus, Science, 27 May 2011, and references therein. Bibcode 2011Sci...332.1149W. doi:10.1126/science.1202098. Accessed 30 May 2011</ref> and have since come to be widely disbelieved.<ref>Drahl, C. The Arsenic-Based-Life Aftermath. Researchers challenge a sensational claim, while others revisit arsenic biochemistry, Chem Eng News 90(5), 42-47, January 30, 2012. http://cen.acs.org/articles/90/i5/Arsenic-Based-Life-Aftermath.html; accessed 13 October 2012</ref> Reports refuting the most significant aspects of the original results have been published in the journal of the original research in 2012, including by researchers from the University of British Columbia and Princeton University.<ref>Science. July 8, 2012. GFAJ-1 Is an Arsenate-Resistant, Phosphate-Dependent Organism. doi: 10.1126/science.1218455. Accessed July 10, 2012.</ref><ref>Science. July 8, 2012. Absence of Detectable Arsenate in DNA from Arsenate-Grown GFAJ-1 Cells.</ref> Following the publication of the articles challenging the conclusions of the original Science article first describing GFAJ-1 it was argued that the original article should be retracted because of misrepesentation of critical data.<ref>http://retractionwatch.wordpress.com/2012/07/09/despite-refutation-science-arsenic-life-paper-deserves-retraction-scientist-argues/#comments</ref>
 
==See also==
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