Tough Bacteria Love to Eat Radiation

Bacteria can live in extreme cold, intense radiation, and corrosive acid. Now, scientists have discovered microbes that can feed on thin gases, giving new hope to the idea of life on other worlds...

The sound of field spades that are forced into the rocky ground breaks the silence on the coast of the world’s most desolate continent. A small group of scientists are standing in one of Antarctica’s hostile landscapes, where no water, nutrients in the ground, nor sunlight are available for most of the year. Hence, the harsh environment does not meet one single one of the basic requirements of life.

Still, back in the lab at the University of Queensland, the Australian scientists can see that their soil samples include no less than 23 unknown bacteria species. Studies show that the bacteria feed on nothing but air thanks to special enzymes that can extract energy from atmospheric gases such as hydrogen, carbon dioxide, and carbon monoxide. This is unusual, even for extremely die-hard bacteria, and the discovery is only the latest of many, that have contributed to biologists’ understanding of life.

The extreme life forms can help us free Earth of toxic heavy metals and radioactive waste. Moreover, the bacteria promise well for the search for life in space, as they can give scientists an idea of how organisms might survive on other planets and moons. Life is amazing On Earth, we have organisms that can survive temperatures of up to 125 °C, whereas others tolerate temperatures of down to -80 °C. Some live deep in the ocean, where the pressure is 100 times higher than at the surface. Others thrive in acid or basic environments, which would quickly corrode the skin of a human. These die-hard life forms are known as extremophiles.

The vast majority of the world’s species can only survive in environments with moderate temperatures of 20-45 °C and neutral pH values of 6.5-7.5. All life forms can be extremophile, but by far the most of the ones that scientists know about today are simple microbes such as bacteria, yeast cells, and other monocellular organisms.

One of the first spectacular discoveries of extremophiles was made in 1977, when scientists first explored the hydrothermal vents at the bottom of the deep sea off the Galápagos Islands. Hydrothermal vents are small cracks in Earth’s crust, where heat from the planet’s interior escapes into the ocean. The environment around them is extremely hostile, as the vents emit toxic gases from the underground, heating the water to some 100 °C. Moreover, they are located so deep below the surface that it is pitch-dark, and the pressure