US space agency finds new form of life… on Earth

WASHINGTON, December 3, 2010 (AFP) – Bacteria that thrive on arsenic have been scooped from a California lake, a discovery that redefines the building blocks of life and offers new hope in the search for other organisms on Earth and beyond. Not only do the bacteria survive, they grow by swapping phosphorus for arsenic in their DNA and cell membranes, said the study funded by the US space agency NASA and published Thursday in the journal Science.

The findings add a new dimension to what biologists consider the necessary elements for life, currently viewed as six elements: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur.

“What we’ve found is a microbe doing something new — building parts of itself out of arsenic,” said scientist Felisa Wolfe-Simon, a fellow in NASA’s astrobiology program who made the groundbreaking discovery at Mono Lake in eastern California.

“There’s an organism on Earth doing something different,” said Wolfe-Simon. “We’ve cracked open the door to what’s possible for life elsewhere in the universe. And that’s profound.”

Ariel Anbar, a co-author of the study, explained how Wolfe-Simon was able to get the bacteria known as strain GFAJ-1 of the Halomonadaceae family of Gamoproteobacteria to grow u