Heat Killing of Bacillus subtilis Spores in Water Is Not Due to Oxidative Damage

The heat resistance of wild-type spores of Bacillus subtilis or spores (termed α(−)β(−)) lacking DNA protective α/β-type small, acid-soluble spore proteins was not altered by anaerobiosis or high concentrations of the free radical scavenging agents ethanethiol and ethanedithiol. Heat-killed wild-type and α(−)β(−) spores exhibited no increase in either protein carbonyl content or oxidized bases in DNA. These data strongly suggest that oxidative damage to spore macromolecules does not contribute significantly to spore killing by heat.