Scientists discover microbes that survive extreme environment

June 10th, 2012 - 2:59 pm ICT by IANS  

Washington, June 10 (IANS) Researchers have discovered organisms that eke out a living in some of the most inhospitable soils on Earth and appear to have a different way of converting energy than other microbes.

A new DNA analysis of rocky soils in the martian-like landscape on some volcanoes in South America has revealed a handful of bacteria, fungi, and other rudimentary organisms, called archaea, which seem to have a different way of converting energy than their cousins elsewhere in the world.

“We haven’t formally identified or characterized the species, but these are very different than anything else that has been cultured,” Ryan Lynch, microbiologist with the University of Colorado in Boulder, who is one of the finders of the organisms, was quoted as saying in the Journal of Geophysical Research-Biogeosciences.

“Genetically, they’re at least five percent different than anything else in the (DNA) database of 2.5 million sequences. The database represents a close-to comprehensive collection of microbes,” he added, said a university statement.

Life gets little encouragement on the incredibly dry slopes of the tallest volcanoes in the Atacama region, where Lynch’s co-author, University of Colorado microbiologist Steven Schmidt, collected soil samples.

Ultraviolet radiation in this high-altitude environment can be twice as intense as in a low-elevation desert. And, while the researchers were on site, temperatures dropped to minus 10 degrees Celsius one night, and spiked to 56 degrees Celsius the next day.

How the new found organisms survive under such circumstances remains a mystery.

Although Lynch, Schmidt, and their colleagues looked for genes known to be involved in photosynthesis, and peered into the cells using fluorescent techniques to look for chlorophyll, the scientists couldn’t find any evidence that the microbes were photosynthetic.

Instead, they think the microbes might slowly convert energy by means of chemical reactions that extract energy and carbon from wisps of gases such as carbon monoxide and dimethyl sulphide that blow into the desolate mountain area.

The process wouldn’t give the bugs a high energy yield, Lynch said, but it could be enough as it adds up over time.

While normal soil has thousands of microbial species represented in just a gram of soil, and even more in garden soils, remarkably few species have made their home in the barren Atacama mountain soil, the new research suggested.

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