Microbes Sleeping 100 Million Years on the Ocean Floor Have Awakened

They even existed before the mighty dinosaurs

Imagine finding organisms that predate virtually everything on the planet. It is hard to fathom what this could mean to our understanding of the world.

Perhaps these new findings will reveal more about life.

Earth’s development of life

These microbes were buried in the dirt some 101.5 million years ago, before Tyrannosaurus rex when the massive carnivorous dinosaur, known as Spinosaurus, ruled the planet. Since that time, many things occurred, our continents shifted, the Earth’s oceans rose and fell, the great primate was formed, and then the first humans were evolved.

Those humans possessed the curiosity, followed by developing the skills required to find and dig up those ancient microbes. This brings us to today when scientists have brought these organisms back to life in a Japanese lab.

Finding ancient microbes

This research team collected samples of sediment from the ocean’s floor while aboard the drillship JOIDES Resolution. The samples were residing some 328 feet underneath the 20,000-foot-deep bottom of the South Pacific Gyre.

This area of the Pacific Ocean has very little oxygen and few nutrients for any life to survive. Scientists were particularly interested in how microbes can live in a part of the world that is so remote.

“Our main question was whether life could exist in such a nutrient-limited environment or if this was a lifeless zone,” said Yuki Morono, who is a scientist from the Japan Agency for Marine-Earth Science and Technology, and also the primary author of a research report about the microbes. “And we wanted to know how long the microbes could sustain their life in a near-absence of food.”

The ancient microbes were fed

The ancient microbes were fed

Their findings reveal that even these organisms found in these 101.5 million-year-old sediment samples can be awakened whenever nutrients and oxygen are suddenly available.

“At first, I was skeptical, but we found that up to 99.1% of the microbes in sediment deposited 101.5 million years ago were still alive and were ready to eat,” Morono pointed out.

These ancient microbes had previously suspended all activity. But after they were given nutrients, along with the other necessities of life, they came to life.

To guard against any contamination from modern microbes, the research team only exposed the samples in highly sterile environments. This was followed by choosing from present microbial cells and feeding nutrients exclusively through a tiny tube designed to protect against contaminants.

The cells responded rapidly. They quickly took in the nitrogen and carbon. Within 68 days, the cell count had quadrupled.

Survival secret of the ancient microbes

Aerobic bacteria — who are oxygen breathers — are the sturdiest cells and most likely to be awakened. These microbes lived on tiny air bubbles that find their way down into sediment over these geologic timescales.

But the real secret of their remarkable survival lies in their metabolic rate. It is just slow enough for them to survive for such long periods.