Diversity of Ferrous Iron-Oxidizing, Nitrate-Reducing Bacteria and their Involvement in Oxygen-Independent Iron Cycling

By K. Straub, W. Schönhuber, B. Buchholz-Cleven, B. Schink. 2004

262 citations recorded by the source corpus.

In previous studies, three different strains (BrG1, BrG2, and BrG3) of ferrous iron-oxidizing, nitrate-reducing bacteria were obtained from freshwater sediments. All three strains were facultative anaerobes and utilized a variety of organic substrates and molecular hydrogen with nitrate as electron acceptor. In this study, analyses of 16S rDNA sequences showed that strain BrG1 was affiliated with the genus Acidovorax, strain BrG2 with the genus Aquabacterium, and strain BrG3 with the genus Thermomonas. Previously, bacteria similar to these three strains were detected with molecular techniques in MPN dilution series for ferrous iron-oxidizing, nitrate-reducing bacteria inoculated with different freshwater sediment samples. In the present study, further molecular analyses of these MPN cultures indicated that the ability to oxidize ferrous iron with nitrate is widespread amongst the Proteobacteria and may also be found among the Gram-positive bacteria with high GC content of DNA. Nitrate-reducing bacteria oxidized ferrous iron to poorly crystallized ferrihydrite that was suitable as an electron acceptor for ferric iron-reducing bacteria. Biologically produced ferrihydrite and synthetically produced ferrihydrite were both well suited as electron acceptors in MPN dilution cultures. Repeated anaerobic cycling of iron was shown in a coculture of ferrous iron-oxidizing bacteria and the ferric iron-reducing bacterium Geobacter bremensis. The results indicate that iron can be cycled between its oxidation states +II and +III by microbial activities in anoxic sediments.

Subfields: Biomedical Engineering, Environmental Engineering, Geochemistry and Petrology

View Paper: https://www.semanticscholar.org/paper/b04afb3f206c2614ca2f99ef3fa53815bf97641a

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Biomedical Engineering

1. A. Kappler
2. K. Straub

In Environmental Engineering

1. A. Kappler
2. P. Larese-Casanova
3. S. Haderlein
4. J. Weiss
5. D. Emerson
6. K. Straub

In Geochemistry and Petrology

1. A. Kappler
2. P. Larese-Casanova
3. S. Haderlein
4. J. Weiss
5. D. Emerson
6. Jeremy A. Rentz

Citations in the corpus

• Biomineralization of lepidocrocite and goethite by nitrate-reducing Fe(II)-oxidizing bacteria: Effect of pH, bicarbonate, phosphate, and humic acids (2010, background): “Aerobic and anaerobic iron(II)-oxidizing bacteria contribute to iron, carbon, and nutrient cycling within a variety of freshwater, groundwater, and marine environments (Straub and Buchholz-Cleven, 1998; Emerson and Moyer, 2002; Emerson and Weiss, 2004; Straub et al., 2004).”
• Fe(III) mineral formation and cell encrustation by the nitrate‐dependent Fe(II)‐oxidizer strain BoFeN1 (2005, background): “A nitrate-dependent Fe(II)-oxidizing freshwater strain (strain BrG1) also affiliated with the genus Acidovorax, but isolated from a different environment, has been described earlier (Straub et al., 2004).”
• Bacterial Iron Oxidation in Circumneutral Freshwater Habitats: Findings from the Field and the Laboratory (2004, background): “The article by Straub et al. in this issue discusses anaerobic Fe-oxidation in more detail (Straub et al. 2004).”
• Geomicrobiological cycling of iron (2005, background): “Biologically produced ferrihydrit~ has been shown to be an excellent electron acceptor tor Fe(III)-reducing bacteria, which reduced it completely to the ferrous stare (Straub et al. 1998, 2004).”