Scientists awaken sea microbes after 100M years of sleep

SCIENTISTS have successfully revived microbes that had lain dormant at the bottom of the sea since the age of the dinosaurs, allowing the organisms to eat and even multiply after eons in the deep.

Their research sheds light on the remarkable survival power of some of Earth’s most primitive species, which can exist for tens of millions of years with barely any oxygen or food before springing back to life in the lab.

A team led by the Japan Agency for Marine-Earth Science and Technology analysed ancient sediment samples deposited more than 100 million years ago on the seabed of the South Pacific.

The region is renowned for hav ing far fewer nutrients in its sediment than normal, making it a fa r-from-idea l site to maintain life over millennia.

The team incubated the samples to help coax the microbes out of their epochspanning slumber.

Astonishingly, they were able to revive nearly all of the microorganisms.

Lead author Yuki Morono said: “When I found them, I was first sceptica l whether the findings are from some mista ke or a failure i n t he experiment.

“We now know that there is no age limit for [organisms in the] sub-seafloor biosphere.”

Universit y of Rhode Island

Graduate School of Oceanography professor and study co-author Steven D’Hondt said the microbes came from t he oldest sediment drilled from the seabed.

“In the oldest sediment we’ve drilled, with the least amount of food, there are still living organisms, and they can wake up, grow and multiply,” he said.

Morono explained that oxygen traces in the sediment a llowed the microbes to stay a live for millions of years while expending v ir tually no energ y.

Energy levels for seabed microbes “are millions of times lower than that of surface microbes”, he said.

Such levels would be far too low to sustain t he surface microbes, and Morono said it was a myster y how the seabed organisms had managed to sur v ive.

Previous studies have shown how bacteria can live on some of the least hospitable places on Earth, including around undersea vents that are devoid of oxygen.

Morono said the new research, published in the journal Nature Communications, proved the remarkable staying power of some of Earth’s simplest living structures.

“Unlike us, microbes grow t heir population by div isions, so they do not have t he concept of lifespan,” he added.