The Puzzle | The Pieces

Origins
Dr. Karl Stetter is on a mission to find the closest living relative of the first life on Earth. He suspects these primitive life forms may be living in some unusual places. If life began on a young, hot Earth, the descendants of the earliest forms of life may still be living in similar hot environments.

His prime suspect for these old microbes, which he affectionately calls "bugs", is a bacteria called Thermatoga maritima. These "heat loving" bacteria thrive in hot volcanic vents where temperatures rise above 100 degrees Celsius, so Stetter journeyed to the island of Vulcano to collect samples from its vents.

Stetter needed to collect enough of the bacteria to piece together the sequence of its DNA. But it takes trillions of individual bacteria to to give researchers enough samples to map a complete sequence. Samples collected from Vulcano contained only a few bacteria. Therefore, Stetter and his team at the University of Regensburg in Germany, needed to grow more in the lab.

This isn't as easy as it may sound. These bacteria thrive in very hot, high-pressure environments. In the environment we find comfortable, these bacteria will stop reproducing or die. Stetter needed to reproduce the conditions of the vents inside his lab.

His solution was a high tech brewer's vat containing very hot water and just the right amount of hydrogen and sulfur. After experimenting with the environment inside the vats, Stetter was eventually successful in growing more of the Thermatoga in the lab. Like a gardener, he was able to harvest his crop and collect enough DNA required for the next step - finding Thermatoga's place on the tree of life.

The Wonders of Microbes, on the MicrobeWorld.org Web site, has more information on the types of microbes.

The Puzzle | The Pieces

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