Paris | They slept there since the age of dinosaurs: scientists were able to wake up the microbes-old 100 million years ago and were buried under the ocean, in a place yet that is not conducive to life, according to a study.
The results, published in the journal Nature Communications, reveal the amazing capabilities of one of the forms of life the most primitive appeared on Earth, which can survive for tens of millions of years with almost no oxygen and no nutrients, and be reborn to life in a laboratory.
Ten years ago, a scientific expedition was going to drill through the depths of the Pacific ocean, and took samples of ancient sediment deposits buried 100 metres below the sea floor (close to 6,000 metres below the surface of the water), some for over 100 million years.
The research team, led by the japanese agency of science and technology under the sea, had chosen the subtropical gyre of the South Pacific, the area that is the least active of all the ocean, because that is extremely poor in nutrients. And thus, a priori, very unlikely to be conducive to life.
The researchers placed the samples in incubation, in order to help the microbes to “get out” of their stupor. To their surprise, they discovered that, far from having been fossilised in the sediments, the microbes had survived, and they were even able to grow and multiply.
“At the beginning I was skeptical, but it turned out that 99.1% of the microbes from the sediment deposits old 101.5 million years ago were still alive, and ready to eat! “commented Yuki Morono, the lead author of the study.
“Now, we know that there is no age limit for the organisms in the biosphere, subsurface marine,” he explained to AFP. “This is a great place to explore the limits of life on Earth “, adds the researcher, in a press release.
These are the traces of oxygen in the sediments, which would have allowed these microbes to stay alive for millions of years without almost consuming energy. The microbes ‘ surface “, themselves, could not survive in such conditions.
Previous studies have shown how bacteria could live in the places most inhospitable of the Earth, even without oxygen. These new research shows the remarkable persistence of these metabolisms.