Mine Yields 253-Million-Year-Old Cellulose

April 15, 2008 -- Cellulose dating back 253 million years -- along with some possible ancient DNA -- has been found in salt crystals from an underground nuclear waste dump in southern New Mexico.

"We did see some ancient DNA in the salt, but not a lot, and we have to continue experiments to try to verify that it is ancient DNA," said Jack D. Griffith, a professor of microbiology and immunology at the University of North Carolina School of Medicine.

Griffith said he thinks looking for cellulose in salt deposits is a good way to go searching for life on other planets because cellulose is tough.

The cellulose -- the same microscopic stuff in wood or cotton -- was water locked in tiny cubes of clear and reddish-brown salt crystals at the federal government's Waste Isolation Pilot Plant near Carlsbad.

The crystals were taken from newly mined areas 2,000 feet below WIPP's desert surface last fall and a couple of years ago, Griffith said last week.

"We found one in a wall that was a couple of feet across, almost looking like into a huge frozen block of ice. The others were found in crystal that is smaller and finer and in jumbles with sulfur or clay deposits," he said.

The research by Griffith and four co-authors was published in the April issue of the journal Astrobiology.

He and his colleagues used a tiny drill -- about the width of a cat's whisker -- to bore into the water-bearing cubes to retrieve drops water as large as one from a standard eyedropper.

"These inclusions contain saturated salt water that is basically a time capsule that is a quarter-of-a-billion years old," Griffith said.

Evaporation cycles from a Permian sea created a 2,000-foot-thick bed of salt.

The water drops were placed in a centrifuge and the remaining pellets were examined with an electron microscope.

"We were thinking we might see bacteria or bacteria viruses or DNA," Griffith said.

"But there were all these mats of this fibrous stuff," which further tests and research found to be cellulose, he said.

The cellulose looks like a web of tangled angel hair pasta. The fibers are about twice the diameter of a DNA molecule.

The discovery of the cellulose, probably remnants of filamentous algae, is significant and exciting, said Karl Niklas, a professor at Cornell University's Department of Plant Biology.