Scientists have discovered a previously unknown species of microbes. Researchers in the USA found them an area below and above the Earth's surface called the Critical Zone. This is essential for sustaining life. The microbes have been called CSP1-3. They could be a key part of the process of water purification. Dr James Tiedje said that while soil is responsible for much of the filtration of rainwater, CSP1-3 may also be indispensable. He said: "CSP1-3 are the scavengers cleaning up what got through the surface layer of soil." They have a job to do to purify our drinking water.

The researchers looked at microbes living in the deep soil, up to 200 metres beneath our feet. They said the microbes remove harmful contaminants from the water supply. Dr Tiedje wants to cultivate CSP1-3 in his lab to find out more about them. He believes they could clean up pollution in the soil. He said: "We don't know their capacities for metabolizing tough pollutants and, if we could learn that, we can help solve one of the Earth's most pressing problems." The scitechdaily.com website said: "Understanding this newly found group could boost conservation efforts."