Description:
<jats:p>
It was found that the de novo synthesis of not only sulfur:ferric ion oxidoreductase (ferric ion-reducing system) but also iron oxidase was absolutely required when
<jats:italic>Thiobacillus ferrooxidans</jats:italic>
AP19-3 was grown on sulfur-salts medium. The results strongly suggest that iron oxidase is involved in sulfur oxidation. This bacterium could not grow on sulfur-salts medium under anaerobic conditions with Fe
<jats:sup>3+</jats:sup>
as a terminal electron acceptor, suggesting that energy conservation by electron transfer between elemental sulfur and Fe
<jats:sup>3+</jats:sup>
is not available for this bacterium.
</jats:p>