A Lazarus bacterium which thrived millions of years before dinosaurs walked the Earth has been brought back to life.
Biologists are astonished that the 250-million-year-old bug could be revived. It suggests that if conditions are right, bacterial spores might survive indefinitely.
John Parkes, a geomicrobiologist at the University of Bristol, comments: 鈥淎ll the laws of chemistry tell you that the complex molecules in the spores should have degraded to very simple compounds such as carbon dioxide.鈥�
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He wonders that if it is proven that spores can survive this long, why should they die at all? 鈥淲here else are these dormant organisms waiting to be reawakened?鈥�
Born survivor
The born-again bacterium is unknown to science and has provisionally been named Bacillus permians, to denote the geological period from which it originates.
鈥淚t is alive and, to the best of anyone鈥檚 knowledge, there鈥檚 no other organism that鈥檚 been around that long,鈥� says Russell Vreeland, the scientist who discovered the bacterium. Its nearest 鈥渁ncient鈥� rivals are bacterial babes by comparison, just 25 to 40 million years old (快猫短视频, 17 May 1997, p 7).
Vreeland and his colleagues at West Chester University in Pennsylvania isolated the ancient bacterium from the Salado salt formation at Carlsbad, New Mexico, in an underground cavern used for storing nuclear waste.
While the salt crystals were forming 250 million years ago, bacterial spores in a drop of water became trapped in a cavity in the salt 鈥� a feature known as a fluid inclusion. The layer where the crystal was found is 560 metres down a shaft leading to the repository.
Under scrupulously sterile conditions, Vreeland liberated the spores from their hibernation and squirted them onto growth medium. The spores grew into familiar rod-shaped bacillus bacteria.
鈥淚 think the cell wall is a little thicker than in normal bacillus bacteria,鈥� he says. Vreeland is now comparing the genes of the ancient bug with those of two contemporary relatives: Bacillus marismortui, from the Dead Sea, and Virgibacillus pantothenticus.
More at: Nature (vol 407, p 897)