Salt-loving microbes and outer space

Utah’s Great Salt Lake is teeming with a life form that may turn out to be inhabiting other planets.

Ancient salty lake beds on Mars may still be home to life
Ancient salty lake beds on Mars may still be home to life

This inland sea is home to dozens of species of salt-loving micro-organisms called halophiles that thrive in one of the most inhospitable environments on Earth.

The discovery of organisms that thrive in the conditions biological dogma once told us were impossible for life is now becoming commonplace.

Collectively known as extremophiles, these life forms selectively embrace extremes of heat, cold, acidity, pressure, radiation and of course salinity.

Their very toughness has attracted not only inquisitive scientists, but the biotech industry, which hopes to capitalise on the enzymes which enable these organisms to survive where nothing else can.

Research in progress

Dr Bonnie Baxter of Salt Lake City’s Westminster College and Dr Shil DasSarma of the University of Maryland plan to create the first inventory of the lake’s microbes.

To date, all that is known is that the Great Salt Lake microbes use solar-powered salt pumps to keep their internal salt concentrations lower than the water around them.

“When I see this lake, I think ‘why is it any different to an evaporated saline lake on Mars? What if I had a chunk of that lake bed on Mars – what kind of things could I grow from that?'”


Dr Bonnie Baxter,
Salt Lake scientiest

But to drive those pumps, the microbes need to be at the surface which means basking in the Sun’s damaging ultraviolet light all day.

To shield themselves against damage to their DNA, the microbes produce pink-coloured pigments called carotenoids – a form of sunscreen.

The Salt Lake discovery may have extra-terreristrial consequences. Many scientists have argued for some time that if bacteria can survive such conditions there, then it is quite possible on other planets such as Mars.

Mars link?

As NASA’s Opportunity has proved bodies of open water did once exist, the Red Planet may well be home to microbes a lot like the halophiles of the Great Salt Lake.

The space agency certainly thinks so. Suddenly, sample-return missions are back on the agenda and Meridiani Planum is being spoken of as a prime destination to go and fetch rocks for study back on Earth.

The prospect of having a chunk of Martian evaporate in an Earth lab, maybe with ancient salt crystals embedded, is an exciting one for the extremophile scientists.

In 2000, researchers actually managed to revive 250-million-year-old halo-tolerant bacteria found on Earth in underground salt crystals.

This suggests the same may be possible for samples from Mars.

Source : News Agencies

More from News
Most Read