Neutrophilic Bacteria in Iron Mineral Transformation and Their Applications

Abstract

AbstractIron, being the fourth abundant metal, is widely distributed in the earth. Iron is a redox-active transition metal existing in both the oxidation states in the form of ferric iron minerals (goethite, ferrihydrite, hematite) and ferrous iron minerals (pyrite, siderite, vivianite). At circumneutral pH, ferrous [Fe (II)] ion is unstable and is rapidly oxidized to ferric [Fe (III)] under aerobic conditions. Conversely, Fe (III) reduction takes place under anaerobic/anoxic conditions at circumneutral pH. Iron mineral transformations to a larger extent are microbially mediated by chemolithotrophic microorganisms that utilize iron as electron acceptor or donor to generate energy for their growth resulting in numerous mineral transformations. Hence, according to the pH of the environmental niches in the oxic–anoxic soils and freshwater sediments, neutrophilic iron-oxidizing bacteria (IOB) and iron-reducing bacteria (IRB) play active roles in mineral transformations. These bacteria have phylogenetic origins within different proteobacteria. The natural biogenic transformations by the neutrophilic bacteria with suitable eco-engineering can be adopted in the field of bioremediation to combat the increasing environmental pollution.KeywordsIron MineralTerminal Electron AcceptorHydrous Ferric OxideBanded Iron FormationReductive DissolutionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.