Scientists revive 100-million-year old microbes from deep underground
Microbes discovered deep beneath the seafloor have been slumbering since the dinosaurs roamed. The sediment samples were taken 10 years ago from the South Pacific Gyre, in the expanse of ocean between Australia and South America.
- The sediment cores nearly 20,000 feet below the ocean surface is thought to be lifeless due to few available nutrients.
- Yuki Morono, lead author of the study, said: “Our main question was whether life could exist in such a nutrient-limited environment or if this was a lifeless zone. And we wanted to know how long the microbes could sustain their life in a near-absence of food.”
- The expedition found oxygen in all of the cores, suggesting that if the sediment forms slowly, oxygen could filter all the way down, thus supporting microbes that need oxygen to live.
- Researchers incubated some of the samples with nutrients, and found that the ancient microbes began to stir. 99.1 percent of microbes from 101.5 million years ago were still alive, and began eating when food was made available.
- Steven D’Hondt, co-author of the study, said that the research “shows that there are no limits to life in the old sediment of the world’s ocean. In the oldest sediment we’ve drilled, with the least amount of food, there are still living organisms.”
- Due to limited resources, these microbes focus their energy on maintaining existence, thus evolving very slowly.
- The microbes are older than the oldest multicellular animal, which is a worm thawed out of the Siberian permafrost after a 40,000 year hibernation.
- Some bacteria, however, have been revived from spores in amber from 250 million years ago.