Scientists Revive Ancient Bacteria

Oct. 18, 2000 -- In what sounds like something out of Jurassic Park, bacteriathat lived before the dinosaurs and survived Earth’s biggest massextinction have been reawakened after a 250-million-year sleep in asalt crystal, scientists say.

The bacteria’s age easily beats longevity records set by otherorganisms revived from apparent suspended animation — not tomention Hollywood’s Jurassic Park dinosaurs, cloned fromprehistoric DNA encased in amber.

“Jurassic Park was neat, but this beats it hands down,” saidPaul Renne, a geologist at the University of California atBerkeley. “The idea of having a living glimpse of what life lookedlike 250 million years ago is pretty spectacular.”

A Peek Into Prehistoric Past

If the discovery by Pennsylvania and Texas researchers holdstrue, the bacteria could open a window onto a prehistoric worldthat was both dying and being reborn. It would also show thetenacity of life in the toughest conditions.

Its genetic makeup also could help biologists calibrate theevolutionary clock for the bacterium and its present-day relatives,said Russell Vreeland, a study author and biologist atPennsylvania’s West Chester University.

DNA tests indicate the prehistoric germ is related topresent-day Bacillus, a type of bacteria found in soil, water anddust.

“We all feel reasonably comfortable that this particularorganism isn’t going to attack anything,” Vreeland said.

Found Deep, In Salt

The organism was found in a tiny, fluid-filled bubble inside asalt crystal 1,850 feet underground, about 30 miles east ofCarlsbad, N.M.

At the end of the Paleozoic Era, the area was a vast and barrensalt lake. The world was then experiencing its greatest loss oflife ever. Up 95 percent of all marine species became extinct. Thefirst known dinosaurs date to about 230 million years ago.

“The end of the Paleozoic was such a curious time and we don’treally know what happened,” said Renne, who was not involved inthe research. “This offers the possibility that we may be able tointerrogate some of the organisms that were around.”

The findings were published in Thursday’s issue of the journalNature.

The researchers are confident that the germ has been locked awayin the crystal all these years. Fossils and radiation tests showthat the formation where the sample was found is 250 million yearsold, they said.

Recent Seepage?

Still, there is the possibility the bacteria somehow seeped intothe salt more recently in small drops of water, said Chris McKay, abiologist at NASA’s Ames Research Center.

“Unlike amber or rocks or permafrost, salt is not animpermeable material,” he said.

The scientists pulled about 220 pounds of rock salt from theWaste Isolation Pilot Plant, an underground nuclear waste dump.Fifty-six crystals that showed no signs of contamination weresampled for the presence of bacteria.

One crystal the size of a large postage stamp contained theorganism. Two other strains of bacteria were found and are beingstudied.

The testing was done inside a containment lab at thePennsylvania campus. The scientists said they took pains to preventcontamination.

The researchers believe the bacteria survived as a spore andmetabolized very little or not at all over the years.

Enduring Reputation

Spores are well-known for their longevity. They have been foundin a 118-year-old can of meat, and yeast has been cultured from a166-year-old bottle of porter ale, R. John Parkes of England’sUniversity of Bristol said in a Nature commentary.

In 1995, researchers at California Polytechnic State Universityreported reviving Bacillus bacteria spores from the gut of a beestuck in amber. The bee was estimated to be 25 million to 30million years old.

Since 1960, researchers have reported finding organisms up to650 million years old in salt, but the findings were met withskepticism because of contamination fears.

In any case, the latest study shows that life can exist inside asalt crystal.

“So the next time you sprinkle salt on your food, think of whatelse you might be eating,” Parkes said.