Bacteria withstand 400,000 g

Proving that you don't have to be big to be tough, some microbes can survive gravity more than 400,000 times that felt on Earth, a new study says.

Most humans, by contrast, can tolerate forces equal to about three to five times Earth's surface gravity (g) before losing consciousness.

The extreme "hypergravity" of 400,000 g is usually found only in cosmic environments, such as on very massive stars or in the shock waves of supernovas, said study leader Shigeru Deguchi, a biologist at the Japan Agency for Marine-Earth Science and Technology.

(Related: "Einstein's Gravity Confirmed on a Cosmic Scale.")

Deguchi and his team were able to replicate hypergravity on Earth using a machine called an ultracentrifuge.

The scientists rapidly spun four species of bacteria — including the common human gut microbe Escherichia coli — to create increasingly intense gravity conditions.

The bacteria clumped together into pellets as the gravity increased, but their forced closeness didn't seem to deter growth: All four species multiplied normally under thousands to tens of thousands of times Earth's gravity.

Two of the species — E. coli and Paracoccus denitrificans, a common soil bacteria — grew under the strain of 403,627 g.