Iron oxidizing bacteria

Heterotrophic bacteria Iron-oxidizing bacteria Purple non-sulfur bacteria... 

Metal depositors. Metal-depositing bacteria oxidize ferrous iron (Fe ) to ferric iron (Fe ). Ferric hydroxide is the result. Some bacteria oxidize manganese and other metals. Gallionella bacteria, in particular, have been associated with the accumulation of iron oxides in tubercles. In fact, up to 90% of the dry weight of the cell mass can be iron hydroxide. These bacteria appear filamentous. The oxide accumulates along very fine tails or excretion stalks generated by these organisms. 

Iron-Oxidizing Bacteria. These are aerobic organisms capable of growing in systems with less than 0.5 ppm oxygen. They oxidize iron from ferrous to the ferric state by the following mechanism ... 

The carbon dioxide produced can contribute to the corrosion of metal. The deposits of ferric hydroxide that precipitate on the metal surface may produce oxygen concentration cells, causing corrosion under the deposits. Gallionalla and Crenothrix are two examples of iron-oxidizing bacteria. 

Yagi laid the foundation for the enzymology of CODH when he discovered an enzymatic activity in sulfate-reducing bacteria that oxidizes CO to CO2 (118). Twenty-five years later, the first CODH was purified to homogeneity (119, 120). The homogeneous C. thermo-aceticum CODH was shown to contain 2 mol of nickel, 12 iron, 1 zinc, and 14 acid-labile inorganic sulfide per afS dimeric unit (120). 

Manganese and iron oxidation are coupled to cell growth and metabolism of organic carbon. Microbially deposited manganese oxide on stainless and mild steel alters electrochemical properties related to the potential for corrosion. Iron-oxidizing bacteria produce tubercles of iron oxides and hydroxides, creating oxygen-concentration cells that initiate a series of events that individually or collectively are very corrosive. 

Probably, iron of biogenic magnetite was originated from hydrothermal solution. It is considered that ferric iron of hydrothermal solution was oxidized by iron oxidizing bacteria to form magnetite. 

Iron Oxide Fe304 FeO(OH) Magnetite Ferritin Bacteria-chitons teeth Widespread Magnetic device Iron store... 

Park D, Leeb DS, Jounga JY, Park JM (2005) Comparison of different bioreactor systems for indirect H2S removal using iron-oxidizing bacteria. Process Biochem 40 1461-1467... 

The importance of bacteria in mediating Mn(II) oxidation in certain environments is evident. But, the mechanisms whereby bacteria oxidize Mn(II) are poorly understood. Some bacteria synthesize proteins or other materials that enhance the rate of Mn(II) oxidation (.52). Other strains of bacteria require oxidized manganese to oxidize Mn(II) (53), suggesting that they may catalyse the oxidation of Mn(II) on the manganese oxide surface. Other bacteria may catalyse the oxidation of Mn(II) on iron oxide surfaces, as iron is associated with manganese deposits on bacteria collected in the eastern subtropical North Pacific (54). 

Zhang C, Liu S, Phelps TJ, Cole DR, Horita J, Fortier SM, Elless M, Valley JW (1997) Physiochemical, mineralogical, and isotopic characterization of magnetite-rich iron oxides formed by thermophilic iron-reducing bacteria. Geochim Cosmochim Acta 61 4621-4632... 

Bridge TAM, Johnson DB. 1998. Reduction of soluble iron and reductive dissolution of ferric iron containing minerals by moderately thermophilic iron-oxidizing bacteria. Appl Environ Microbiol 64 2181-6. 

The biological classification schemes for bacteria and archaea are still being developed because of the rapid pace of new discoveries in genomics. The two most important phyla of marine bacteria are the cyanobacteria, which are photosynthetic, and the proteobacteria. The latter include some photosynthetic species, such as the purple photosynthetic bacteria and N2 fixers. Other members of this diverse phylum are the methanotrophs, nitrifiers, hydrogen, sulfur and iron oxidizers, sulfete and sulfur reducers, and various bioluminescent species. 

Ferrihydrite is the iron oxide with the most widespread distribution in living organisms. In the form of ferritin, an iron storage protein, it is found in all organisms from bacteria through to man (in heart, spleen and liver). It occurs in plants as phytoferritin (review by Seckback, 1982). Ferritin plays a key role in iron metabolism it maintains... 

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