Slow-Motion Microbes Still Living Off Dinosaur-Era “Lunch Box”
Buried under the seafloor for 86 million years, a bacterial community lives so slowly it’s still surviving on a “lunch box” from dinosaur days, a new study says. It’s been known since the 1990s that microbes can live trapped in ocean sediments for millions of years, but until now it’s been a mystery how these organisms make a living. Study leader Hans Røy, a geomicrobiologist at Aarhus University in Denmark, found that the deep-sediment bacteria are consuming oxygen at extremely sluggish rates. What’s more, the team discovered the microbes are living off the same supply of organic carbon that got trapped along with them.
“They left the surface world when the dinosaurs walked the planet—and they are still eating the same lunch box that they got back then,” Røy said. And they’re not alone: Such microbes may be the most common organisms on the planet, making up about 90 percent of Earth’s single-celled life, recent research suggests. Because the organisms are so deprived, they’ve also adapted to reproduce very slowly, unlike other bacterial species, many of which multiply by the millions within a few days.