Anaerobic Reduction of Molybdenum by Sulfolobus Species

Abstract

The acidothermophilic Archaebacteria, Sulfolobus acidocaldarius and S. brierleyi, oxidized elemental sulfur anaerobically producing sulfuric acid by using Mo (VI) as an apparent electron acceptor. Molybdenum reduction resulted in the formation of a blue color which was intensified in the presence of aluminum at concentrations of 20–50 mM. Molybdenum was not reduced when S. brierleyi was grown anaerobically on yeast extract as an energy source, suggesting that the organic substrate was utilized in a fermentative metabolism mode.