Journal of Microbial & Biochemical Technology

Abstract

Perspectives on the Biogenesis of Iron Oxide Complexes Produced by Leptothrix, an Iron-oxidizing Bacterium and Promising Industrial Applications for their Functions

Tatsuki Kunoh, Hitoshi Kunoh and Jun Takada

Leptothrix species, one of the Fe-/Mn-oxidizing bacteria, are ubiquitous in aqueous environments, especially at sites characterized by a circumneutral pH, an oxygen gradient and a source of reduced Fe and Mn minerals. Characteristic traits that distinguish the genus Leptothrix from other phylogenetically related species are its filamentous growth and ability to form uniquely shaped microtubular sheaths through the precipitation of copious amounts of oxidized Fe or Mn. The sheath is an ingenious hybrid of organic and inorganic materials produced through the interaction of bacterial exopolymers with aqueous-phase inorganics. Intriguingly, we discovered that Leptothrix sheaths have a variety of unexpected functions that are suitable for industrial applications such as material for lithium battery electrode, a catalyst enhancer, pottery pigment among others. This review focuses on the structural and chemical properties of the Leptothrix sheaths and their noteworthy functions that show promise for development of cost-effective, eco-friendly industrial applications.