An Acid-tolerant Iron-oxidizing Metallogenium

SUMMARY: A filamentous iron bacterium similar to some reported forms of Gallionella and Metallogenium has been isolated in pure culture from a number of widely distributed iron-bearing streams. This organism grows in multi-branching colonies of iron-encrusted filaments (diameter: 0.1 to 0.4 μm) without a conventional cell body. Differentiation of this bacterium from Gallionella and other forms of Metallogenium is based upon morphology, growth requirements, and ability to catalyse iron oxidation under meso-acidic conditions.