Awakening the "dead"

Natural History, May, 2005 by Stephan Reebs

30,000 B.C. -- Biologists have discovered a new bacterium. True, such discoveries are made many times a month--but this bacterium was found alive in 32,000-year-old Alaskan ice. When Richard B. Hoover, a NASA astrobiologist, melted a chunk of the ice back at the lab, out swam short rods with rounded ends. Talk about longevity!

Elena V. Pikuta of NASA, along with Hoover and several other biologist colleagues, cultured the microorganism and studied its DNA and physiology. They soon learned they were dealing with a new species of the genus Carnobacterium. Eight other Carnobacterium species are known today; all are cold specialists, and all can survive either with or without oxygen. Some might even live in your fridge.

So how how did the new bacterium, dubbed C. pleistocenium, manage to lie dormant for so long? The answer isn't clear yet. But the discovery raises hopes that similar organisms could be found on other planets that have or once had ice (think Mars). Unlocking their secrets of dealing with the cold could lead to new methods of cryo-preservation. Another, less hopeful possibility is that the warming of the globe's icebound regions may introduce long-dormant bacteria into today's bacterial gene pool, with unpredictable effects. (International Journal of Systematic and Evolutionary Microbiology 55:473-78, 2005)