DNA Secrets of a Salty Survivor

A microbe that grows in the Dead Sea is teaching scientists about the art of DNA repair.

You can learn a lot from a microbe. Right now, a tiny critter from the Dead Sea is teaching scientists new things about biotechnology, cancer, possible life on other worlds. And that's just for starters:

This microbe, called Halobacterium, may hold the key to protecting astronauts from one of the greatest threats they would face during a mission to Mars: space radiation. The harsh radiation of interplanetary space can penetrate astronauts' bodies, damaging the DNA in their cells, which can cause cancer and other illnesses. DNA damage is also behind cancers that people suffer here on Earth.

Halobacterium appears to be a master of the complex art of DNA repair. This mastery is what scientists want to learn from: In recent years, a series of experiments by NASA-funded researchers at the University of Maryland has probed the limits of Halobacterium's powers of self-repair, using cutting-edge genetic techniques to see exactly what molecular tricks the "master" uses to keep its DNA intact.

"We have completely fragmented their DNA. I mean we have completely destroyed it by bombarding it with [radiation]. And they can reassemble their entire chromosome and put it back into working order within several hours," says Adrienne Kish, member of the research group studying Halobacterium at the University of Maryland.

more Cells of Halobacterium as seen through a high-powered microscope. The individual cells in this image are about 5 microns long.

Being a virtuoso at repairing damaged DNA makes Halobacterium one hardy little microbe: in experiments by the Maryland research group, Halobacterium has survived normally-lethal doses of ultraviolet radiation (UV), extreme dryness, and even the vacuum of space.