Microorganisms pumping iron: anaerobic microbial iron oxidation and reduction

@article{Weber2006MicroorganismsPI,
  title={Microorganisms pumping iron: anaerobic microbial iron oxidation and reduction},
  author={Karrie A. Weber and Laurie A. Achenbach and John D. Coates},
  journal={Nature Reviews Microbiology},
  year={2006},
  volume={4},
  pages={752-764}
}
Iron (Fe) has long been a recognized physiological requirement for life, yet for many microorganisms that persist in water, soils and sediments, its role extends well beyond that of a nutritional necessity. Fe(II) can function as an electron source for iron-oxidizing microorganisms under both oxic and anoxic conditions and Fe(III) can function as a terminal electron acceptor under anoxic conditions for iron-reducing microorganisms. Given that iron is the fourth most abundant element in the… 
Isolation of iron bacteria from terrestrial and aquatic environments
TLDR
The morphologic characteristics of selected isolates under near-natural conditions are examined to assign them to morphologic structures which occur in native samples, including those of neutrophilic iron bacteria and bacteria capable of manganese oxidation.
Nitrate-Dependent Iron Oxidation: A Potential Mars Metabolism
TLDR
The hypothetical viability of microbial nitrate-dependent Fe2+ oxidation (NDFO) for supporting simple life in the context of the early Mars environment is considered, suggesting that such microbes could have persisted in sub-surface aquifers long after the desiccation of the surface.
Toward a Mechanistic Understanding of Anaerobic Nitrate-Dependent Iron Oxidation: Balancing Electron Uptake and Detoxification
TLDR
It is suggested that anaerobic iron-oxidizing microorganisms likely exist along a continuum including: (1) bacteria that inadvertently oxidize Fe(II) by abiotic or biotic reactions with enzymes or chemical intermediates in their metabolic pathways and suffer from toxicity or energetic penalty, and (2) Fe( II) tolerant bacteria that gain little or no growth benefit from iron oxidation but can manage the toxic reactions.
A Single Bacterium Capable of Oxidation and Reduction of Iron at Circumneutral pH
TLDR
This is the first report demonstrating the presence of a single bacterium capable of both Fe(II) oxidation and Fe(III) reduction at circumneutral pH, and this bacterium will help to better understand the molecular mechanisms of microbial Fe redox cycling as a model organism.
Alternative electron transfer pathways in iron-metabolising bacteria
TLDR
Results in this thesis suggest that Acinetobacter (previously described as a strict aerobic microorganism) in fact is capable of respiring using iron when oxygen is not available and point out that extracellular electron transport is not the only mechanism in dissimilatory iron metabolism.
Insight into the evolution of the iron oxidation pathways.
Influence of Oxygen and Nitrate on Fe (Hydr)oxide Mineral Transformation and Soil Microbial Communities during Redox Cycling.
TLDR
Understanding Fe (hydr)oxide transformation under environmentally relevant redox cycling conditions provides insight into nutrient availability and transport, contaminant mobility, and microbial metabolism in soils and sediments.
Repeated Anaerobic Microbial Redox Cycling of Iron
TLDR
The combined chemical and microbiological data suggest that both Geobacter and various Betaproteobacteria participated in nitrate-dependent Fe(II) oxidation in the cycling cultures, which may have important consequences for both the fate of N and the abundance and reactivity of Fe(III) oxides in sediments.
Respiratory interactions of soil bacteria with (semi)conductive iron-oxide minerals.
TLDR
It is suggested that subsurface-clade Geobacter species preferentially thrive in soil by utilizing (semi)conductive iron oxides for their respiration.
...
...

References

SHOWING 1-10 OF 171 REFERENCES
Iron metabolism in anoxic environments at near neutral pH.
TLDR
Recent findings on the physiology of ferric iron-reducing and ferrous iron-oxidizing bacteria are evaluated with respect to their relevance to microbial iron transformations in nature.
Anaerobic Nitrate-Dependent Iron(II) Bio-Oxidation by a Novel Lithoautotrophic Betaproteobacterium, Strain 2002
TLDR
The isolation of strain 2002 represents the first example of an anaerobic, mesophilic, neutrophilic Fe(II)-oxidizing lithoautotrophic bacterium isolated from freshwater samples and provides further evidence for the potential of microbially mediated Fe( II) oxidation in anoxic environments.
Microbiological evidence for Fe(III) reduction on early Earth
TLDR
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.
Anaerobic redox cycling of iron by freshwater sediment microorganisms.
TLDR
The results indicate that the wetland sediments contained organisms such as Geobacter sp.
Organic Matter Mineralization with Reduction of Ferric Iron in Anaerobic Sediments
TLDR
Results indicate that iron reduction can outcompete methanogenic food chains for sediment organic matter when amorphous ferric oxyhydroxides are available in anaerobic sediments, and the transfer of electrons from organic matter to ferric iron can be a major pathway for organic matter decomposition.
Bacterial Iron Oxidation in Circumneutral Freshwater Habitats: Findings from the Field and the Laboratory
TLDR
An overview of the microbial iron cycle is presented with an emphasis on the role of microbes that grow under microaerobic conditions at oxic-anoxic transition zones where Fe(II) is abundant.
Humic substances as electron acceptors for microbial respiration
HUMIC substances are heterogeneous high-molecular-weight organic materials which are ubiquitous in terrestrial and aquatic environments. They are resistant to microbial degradation1 and thus are not
Anaerobic oxidation of ferrous iron by purple bacteria, a new type of phototrophic metabolism
TLDR
Anoxic iron-rich sediment samples that had been stored in the light showed development of brown, rusty patches and the existence of ferrous iron-oxidizing anoxygenic phototrophic bacteria may offer an explanation for the deposition of early banded-iron formations in an assumed anoxic biosphere in Archean times.
Oxidation of aromatic contaminants coupled to microbial iron reduction
TLDR
It is shown that in aquatic sediments, microbial activity is necessary for the oxidation of model aromatic compounds coupled to Fe(III) reduction, providing the first example of an organism of any type which can oxidize an aromatic hydrocarbon anaerobically.
...
...