Microorganisms Discovered beneath Antarctic Glacier
17.04.2009 - Flora & Fauna, Other, Antarctic
Researchers from Dartmouth College reported in Science magazine how a reservoir of brine has been supporting microbes living in isolation beneath an Antarctic glacier for millions of years. These findings provide insight into how life managed to survive Earth's glacial periods and raises hopes that extraterrestrial life might be discovered in inhospitable places such as Mars or Jupiter's icy moon, Europa.
The research took place in Blood Falls, a saltwater outflow beneath Taylor Glacier's subglacial lake in Antarctica's McMurdo Dry Valleys. Water there is rich in iron and becomes rust-coloured when it comes into contact with oxygen. Geomicrobiologist Jill Mikucki has been collecting and testing water samples over 6 years.
- Genetic analysis: the microbes are closely related to other microorganisms that use sulphate (in stead of oxygen) for respiration;
- Isotopic analysis: the microbes modify sulphate into another form for respiration
- Traces of soluble ferrous iron in the water: organisms have been converting ferric iron, which is insoluble, to a soluble ferrous form.
What this shows is that these organisms are able to "breathe" the iron leached from the bedrock with the help of sulphur as a catalyst. Lacking any light to support photosynthesis, the microbes have presumably survived by feeding on the organic matter that was trapped with them when the massive Taylor Glacier sealed off their habitat an estimated 1.5 to 2 million years ago.
