Deinococcus radiodurans, or D. radiodurans, is a bacterium which is thought to be the most resilient in the world. It is able to cope without air, water and food, and can withstand very high doses of radiation which would kill a human. The Deinococcus radiodurans genome, the genetic information required for the microbe to repair itself, is stored in the form of a number of copies, rather than the usual single backup copy. This makes it possible for enough genetic material to be recovered to make one complete genome if the microorganism has been damaged by radiation. Scientists have proposed a number of uses for Deinococcus radioduran, including cleaning up contaminated areas after exposure to radiation and toxic substances, a process known as bioremediation.
During the 1950s, scientists discovered Deinococcus radiodurans in canned meat which had been treated with radiation yet had still become spoiled. In addition to the fact that in Deinococcus radiodurans, DNA is replicated to provide several copies of its genome, the microorganism has other features which are useful for survival. Enzymes help to protect it against oxygen damage and carotenoid pigments defend it from attack by free radicals. A thick and complex cell wall also acts as a protective barrier between D. radiodurans and high levels of radiation.
Deinococcus radiodurans bioremediation, where the bacteria are used to process dangerous chemicals in hostile environments, involves genetic engineering of D. radiodurans to create a superbug. Several microorganisms are already known which have the ability to process a specific toxic chemical but which lack the robustness to stand up to other chemicals which might be present in the same environment. Genes from these microbes can be added to Deinococcus radiodurans to produce a much sturdier bacterium with the same abilities.
It is thought that Deinococcus radiodurans could be useful in space exploration and research. Conditions on Mars, where potential problems for humans include exposure to a vacuum, intense cold and radiation, would all be survivable for D. radiodurans. This means it is potentially useful as a substitute for Mars microbes in research involving simulations of the Martian environment. If humans ever land on Mars, there is also the possibility that, through genetic engineering, Deinococcus radiodurans could be used to manufacture drugs on demand, avoiding the need to store medicines with expiration dates in large quantities on board a spaceship. Potentially, if humans settle on Mars, D. radiodurans could be used to produce food, process waste or even to alter the environment to make it more suitable for people, in a process known as terraforming.
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