IT THRIVES in natural saunas hotter than boiling water, where there鈥檚 only
hydrogen and carbon dioxide for fuel. Now the genetic machinery of this unique
bacterium has been laid bare by a biotech company, which hopes to exploit some
of the weird proteins that keep the bug alive in such extreme conditions.
Pyrolobus fumarii survives at higher temperatures than any other
known living organism. Diversa Corporation of San Diego, California, announced
last week that it now has the complete sequence of the bug鈥檚 genome in the bag.
The sequencing was done for Diversa by Celera Genomics, the company that
sequenced the human genome.
The complete genome should turn up some intriguing new discoveries, says
Hillary Theakston, a spokeswoman for Diversa: 鈥淚t would produce some pretty
unusual chemistry.鈥� It turns out that less than 10 per cent of the bacterium鈥檚
2000 genes have been found in other bacteria.
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Five years ago, a research submarine called Alvin found P. fumarii
3.5 kilometres down in the Mid-Atlantic Ridge. It lives on the walls of 鈥渂lack
smokers鈥�, natural vents on the sea floor that spew hot gases into the ocean.
Karl Stetter and his colleagues at the University of Regensburg in Germany
discovered the bacterium and named it P. fumarii (meaning 鈥渢he fire
lobe of the chimney鈥�) after analysing samples from the sub.
Stetter, who is now a member of Diversa鈥檚 scientific advisory board, found
that P. fumarii is happiest at temperatures between 90 and 113 掳C
and can survive pressures of 250 atmospheres. It thrives in the airless
underwater hothouse by metabolising the hydrogen and carbon dioxide which spew
from ocean vents.
As well as revealing new enzymes with unusual commercial applications, this
bacterium and other similar ones could shed light on whether life exists on
other planets. 鈥淏ecause they require only the basic nutrients generated by
volcanism, these organisms would be able to exist on any planet that possessed
volcanic activity and liquid water,鈥� Stetter says.