Arsenic-loving bug theory disproved
7/8/12 - In a paper published in Science that is getting wide play in national media, a group of researchers that includes Marshall Reaves, Joshua Rabinowitz, and Leonid Kruglyak from Princeton University, disproves the sensational claim (reported last year in Science) that, under phosphate limiting conditions, arsenate could replace phosphorous in the DNA of a microbe.
The Science abstract reads: A strain of Halomonas bacteria, GFAJ-1, has been claimed to be able to use arsenate as a nutrient when phosphate is limiting, and to specifically incorporate arsenic into its DNA in place of phosphorus. However, we have found that arsenate does not contribute to growth of GFAJ-1 when phosphate is limiting and that DNA purified from cells grown with limiting phosphate and abundant arsenate does not exhibit the spontaneous hydrolysis expected of arsenate ester bonds. Furthermore, mass spectrometry showed that this DNA contains only trace amounts of free arsenate and no detectable covalently bound arsenate.
Full Citation: Absence of Detectable Arsenate in DNA from Arsenate-Grown GFAJ-1 Cells, M. L. Reaves, S. Sinha, J. D. Rabinowitz, L. Kruglyak, R. J. Redfield. Science 1219861. Published online 8 July 2012. [DOI:10.1126/science. 1219861]