Breathing Iron: Molecular Mechanism of Microbial Iron Reduction by Shewanella oneidensis

  title={Breathing Iron: Molecular Mechanism of Microbial Iron Reduction by Shewanella oneidensis},
  author={Rebecca E. Cooper and Jennifer L. Goff and Ben Reed and Ramanan Sekar and Thomas J. DiChristina},
Dissimilatory Fe(III)-reducing bacteria occupy a central position in a variety of environmentally important processes, including the biogeochemical cycling of carbon and iron, the bioremediation of radionuclides and organohalides, and the generation of electricity in microbial fuel cells. Fe(III)-reducing bacteria are scattered and deeply rooted throughout both prokaryotic domains, an indication that microbial Fe(III) reduction may also have been one of the first respiratory processes to have… 

Metal Reduction and Protein Secretion Genes Required for Iodate Reduction by Shewanella oneidensis

The main objective of the present study was to determine the metal reduction and protein secretion genes required for IO3− reduction by Shewanella oneidensis with lactate, formate, or H2 as the electron donor.

Fe(III) Oxide Reduction by Anaerobic Biofilm Formation-DeficientS-Ribosylhomocysteine Lyase (LuxS) Mutant of Shewanella oneidensis

LuxS is thus required for wild-type anaerobic biofilm formation on Fe(III) oxide surfaces, yet the inability to form wild- type an aerobic biofilms on Fe (III)oxide surfaces does not alter Fe( III) oxide reduction activity.

Iodate Reduction by Shewanella oneidensis Does Not Involve Nitrate Reductase

Findings provide the first genetic evidence that IO3− reduction by S.oneidensis does not involve nitrate reductase and indicate that S. oneidensis reduces IO3 − via an as yet undiscovered enzymatic mechanism.

Ferrihydrite-associated organic matter (OM) stimulates reduction by Shewanella oneidensis MR-1 and a complex microbial consortia

Abstract. The formation of Fe(III) oxides in natural environments occurs in the presence of natural organic matter (OM), resulting in the formation of OM–mineral complexes that form through

Iodate Reduction by Shewanella oneidensis Requires Genes Encoding an Extracellular Dimethylsulfoxide Reductase

Results of this study provide complementary genetic and phenotypic evidence that the extracellular DMSO reductase complex DmsAB of S. oneidensis displays broad substrate specificity and reduces IO3– as an alternate terminal electron acceptor.

Application of Shewanella to Water Treatment Issues

This chapter examines current and prospective applications of Shewanella to water treatment issues, highlighting biochemical details associated with each technology.

Extracellular sulfite is protective against reactive oxygen species and antibiotic stress in Shewanella oneidensis MR-1.

The results showed that sulfite is the major extracellular sulfur metabolite released to the growth medium under both aerobic and anaerobic growth conditions, and exogenous sulfite at physiological concentrations protected S. oneidensis MR-1 from hydrogen peroxide toxicity and enhanced tolerance to the beta-lactam antibiotics.

Activation of an Otherwise Silent Xylose Metabolic Pathway in Shewanella oneidensis

The activation of an otherwise silent xylose metabolic system in Shewanella oneidensis is a powerful example of how accidental mutations allow microorganisms to adaptively evolve.



Dissimilatory Fe(III) and Mn(IV) reduction.

Enzymology of Electron Transport: Energy Generation with Geochemical Consequences

Dissimilatory metal-reducing bacteria (DMRB) are important components of the microbial community residing in redox-stratified freshwater and marine environments. DMRB occupy a central position in the

Dissimilatory iron reduction in Escherichia coli: identification of CymA of Shewanella oneidensis and NapC of E. coli as ferric reductases

The data support the argument that the biochemical mechanism of Fe(III) reduction per se was not the key innovation leading to environmental relevant DIR bacteria, and the evolution of an extension of the electron transfer pathway from the Fe( III) reductase CymA to the cell surface via a system of periplasmic and outer membrane cytochrome proteins enabled access to diffusion‐impaired electron acceptors.

Effects of Fe(III) chemical speciation on dissimilatory Fe(III) reduction by Shewanella putrefaciens.

Results indicate that dissimilatory Fe(III) reduction by S. putrefaciens is controlled by equilibrium competition for Fe(II) between dissolved organic ligands and strongly sorbing functional groups on the cell surface, implying that chemical speciation governs Fe( III) bioavailability.

Secretion of Flavins by Shewanella Species and Their Role in Extracellular Electron Transfer

Flavin mononucleotide and riboflavin are identified for the first time as the extracellular electron shuttles produced by a range of Shewanella species and shown to act as electron Shuttles and to promote anoxic growth coupled to the accelerated reduction of poorly crystalline Fe(III) oxides.

Microbiological evidence for Fe(III) reduction on early Earth

It is shown that Archaea and Bacteria that are most closely related to the last common ancestor can reduce Fe(III) to Fe(II) and conserve energy to support growth from this respiration and even Thermotoga maritima, previously considered to have only a fermentative metabolism, could grow as a respiratory organism when Fe( III) was provided as an electron acceptor.

Review: microbial mechanisms of accessing insoluble Fe(III) as an energy source

Of all the terminal electron acceptors, Fe(III) is the most naturally abundant in many subsurface environments. Fe(III)-reducing microorganisms are phylogenetically diverse and have been isolated

c-Type Cytochrome-Dependent Formation of U(IV) Nanoparticles by Shewanella oneidensis

It is shown that c-type cytochromes of a dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1, are essential for the reduction of U(VI) and formation of extracelluar UO 2 nanoparticles and this is the first study to the authors' knowledge to directly localize the OM-associated cyto Chromes with EPS, which contains biogenic UO2 nanoparticles.

Mechanisms for Accessing Insoluble Fe(III) Oxide during Dissimilatory Fe(III) Reduction by Geothrix fermentans

This is the first demonstration of a microorganism that, in defined medium without added electron shuttles or chelators, can reduce Fe( III) derived from Fe(III) oxide without directly contacting the Fe(II) oxide.

Extracellular electron transfer via microbial nanowires

Results indicate that the pili of G. sulfurreducens might serve as biological nanowires, transferring electrons from the cell surface to the surface of Fe(iii) oxides, indicating possibilities for other unique cell-surface and cell–cell interactions, and for bioengineering of novel conductive materials.