A BUG discovered deep in the ground has got astrobiologists buzzing. The organism鈥檚 unique ability to live in complete isolation from other species, or even light or oxygen, suggests it could be the key to life on other planets.
It was discovered in fluid-filled cracks in a South African gold mine, nearly 3 kilometres beneath the Earth鈥檚 surface. When Dylan Chivian of the Lawrence Berkeley National Laboratory, California, analysed the fluid, he expected to find genes from a mix of species. Instead, he found that 99.9 per cent of the DNA belonged to just one bacterium, a previously unknown species which has now been named Candidatus Desulforudis audaxviator (Science, ).
Such a self-sufficient organism is virtually unheard of. It means the ecosystem鈥檚 only species must extract everything it needs from an otherwise dead environment. 鈥淰irtually all other known ecosystems on Earth that don鈥檛 use sunlight directly do use some product of photosynthesis,鈥� says Carl Pilcher, director of NASA鈥檚 Astrobiology Institute.
Advertisement
Chivian鈥檚 analysis shows that the new bacterium gets its energy from the radioactive decay of uranium in the surrounding rocks. It also has genes to extract carbon and nitrogen from its environment 鈥� both essential for making proteins.
鈥淚t鈥檚 philosophically exciting to know that everything necessary for life can be packed into a single genome,鈥� says Chivian. NASA鈥檚 Chris McKay says this is just the kind or organism that could survive on Mars.
Astrobiology 鈥� Learn more in our out-of-this-world .
