Comment Oldish news being confirmed by NASA (Score 1) 405
I'm pretty sure this was discovered some months ago...however, these articles don't mention anything about the bacteria's DNA. Perhaps that's the new discovery NASA made.
http://www.newscientist.com/article/dn14537-arseniceating-bacteria-rewrite-evolutionary-history.html
http://water.usgs.gov/nrp/highlights/arsenic.html
http://news.bbc.co.uk/2/hi/science/nature/7558448.stm