Whatever the mechanism, this tolerance to heat is startling, and it lends support to the old idea of panspermia, the possible transfer of life between planets. How do the Bacillus spores do it? Gheysens thinks the bacteria must have a protein-based repair mechanism, or an RNA- or DNA-template that’s able to repair DNA damaged by excessive heat. More than 90 percent of spores could be “resurrected” after heating to 300 o C, and about 40 percent after being heated to 420 o C. The researchers collected microorganisms within soils from Jordan, Tunisia, Morocco and the Canary Islands, and showed that the hardiest of them, a Bacillus species from Morocco, could survive in a dried spore stage at temperatures up to 420 o C.
But it’s astonishing just how much heat they can handle. It was previously known that bacteria in this dormant form are much hardier than bacteria in the normal vital state. Bacteria form resistant spore structures when environmental conditions become unfavorable.
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