ARSENIC BACTERIUM DEBATE CONTINUES

Abstract

A VOLLEY OF CRITICISM against a claim that a certain extremophile bacterium from arsenic-rich Mono Lake in California incorporates arsenic into its DNA backbone was published in the June 3 issue of Science, (2011, 332, 1149). The claim, if true, would alter the fundamental understanding of carbon-based life and opens a wider window to the possibilities for extraterrestrial life. The original work, by astrobiologist Felisa Wolfe-Simon and colleagues, was published online in Science in December 2010 (C&EN, Dec. 13, 2010, page 7). The original papper also appears in the June 3 issue of Science . The published criticisms—a series of so-called technical comments—echo the chorus of skepticism from experts in origin-of-life science and DNA biochemistry that greeted the original claim. In his technical comment, for example, synthetic biology pioneer Steven A. Benner at the Foundation for Applied Molecular Evolution argues that arsenate esters, the chemicals that supposedly form in the DNA backbone in place ...