Tiny freezing bacteria

[I, Brian]

Ice retrieved from the base of a Greenland glacier has yielded over 15 new species of bacteria - and they are minute, even for microbes.

The diminutive bugs were extremely difficult to culture in the lab, and the US researchers believe the ones they did grow represent only a tiny proportion of the bacteria present in the ice. The team think their minuscule size may be key to their survival under the freezing and exceptionally dry conditions.

When Vanya Miteva and Jean Brenchley at Pennsylvania State University recovered ice cores from three kilometres deep in a Greenland glacier they were astonished by the numbers of bacteria they found. One millilitre of melted ice contained between one and 10 million cells.

The ice formed around 120,000 years ago, but might contain permafrost that had been frozen for millions of years.

The team found that most of the bacteria were extremely small, fitting into the category of ultra-micro bacteria. These are smaller than 0.3 micrometres across - regular bacteria range from one to 10 micrometres.


More: http://www.newscientist.com/news/news.jsp?id=ns99995049