2 Million Year-old Ocean Species Survies Breathing Iron

April 18th, 2009

A new species of microbes was discovered in an unlikely place recently. It was dark, cold, and lacked oxygen. Scientist believed that life in this area was not possible, but a reservoir of briny liquid buried deep beneath an Antarctic glacier supports hardy microbes that have lived in isolation for millions of years, researchers report April 17 in the journal Science.

What is so unique is that they have lived by breathing iron leached from bedrock with the help of a sulfur catalyst. Lacking any light to support photosynthesis, the microbes have presumably survived by feeding on the organic matter trapped with them when the massive Taylor Glacier sealed off their habitat an estimated 1.5 to 2 million years ago. Probably about the best diet outside of Decaslim to keep the weight off.

“It’s a bit like finding a forest that nobody has seen for 1.5 million years,” says Ann Pearson, Thomas D. Cabot Associate Professor of Earth and Planetary Sciences in Harvard’s Faculty of Arts and Sciences. “Intriguingly, the species living there are similar to contemporary organisms, and yet quite different — a result, no doubt, of having lived in such an inhospitable environment for so long.”

“This briny pond is a unique sort of time capsule from a period in Earth’s history,” says lead author Jill Mikucki, now a research associate in the Department of Earth Sciences at Dartmouth and visiting fellow at Dartmouth’s Dickey Center for International Understanding and its Institute of Arctic Studies. “I don’t know of any other environment quite like this on Earth.”

“When I started running the chemical analysis on it, there was no oxygen,” she says. “That was when this got really interesting. It was a real ‘Eureka!’ moment.”