Unusual Microbes Found In Harsh Environment

Scientists have discovered a community of microbes in one of the world's most inhospitable regions that is unlike anything seen before.

The Atacama Desert in South America is home to volcanoes as tall as 20,000 feet. The region is so dry, that it hasn't seen ice in 48,000 years.

A team led by University of Colorado at Boulder professor Steve Schmidt found bacteria, fungi, and simple organisms called archaea in soil samples collected from the region.

"We haven't formally identified or characterized the species," said Ryan Lynch, a CU-Boulder doctoral student involved in the study. "But these are very different than anything else that has been cultured. Genetically, they're at least 5 percent different than anything else in the DNA database of 2.5 million sequences."

The microbes do not seem to use photosynthesis, and the scientists theorize that they get energy and carbon from gases such as carbon monoxide and dimethylsulfide. However, these gases exist in such small amounts that the entire process is still a mystery.

The Atacama volcanoes can be an extremely unforgiving environment. During the study, temperatures dropped to 14 degrees Fahrenheit one night, and spiked to 133 degrees Fahrenheit the next. Ultraviolet radiation at that level is also almost twice as much as in a low-elevation desert.

Normal soil can contain thousands of microbes, but the soil that Schmidt and his team examined from the Atacama region contained far less.

"To find a community dominated by less than 20 species is pretty amazing for a soil microbiologist," Schmidt said. "It's mostly due to the lack of water, we think. Without water, you're not going to develop a complex community."

Microbes are usually transported via air and water, but the conditions are so harsh that many microbes are killed as soon as they arrive. The region is also one of the most similar areas on Earth to Mars. Schmidt is working with astrobiologists to further knowledge about the possibility of life on Mars.

"If we know, on Earth, what the outer limits for life were, and they know what the paleoclimates on Mars were like, we may have a better idea of what could have lived there," Schmidt said.