This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Neubauer, S. C.
Right arrow Articles by Megonigal, J. P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Neubauer, S. C.
Right arrow Articles by Megonigal, J. P.
Agricola
Right arrow Articles by Neubauer, S. C.
Right arrow Articles by Megonigal, J. P.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, August 2002, p. 3988-3995, Vol. 68, No. 8
0099-2240/02/$04.00+0     DOI: 10.1128/AEM.68.8.3988-3995.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Life at the Energetic Edge: Kinetics of Circumneutral Iron Oxidation by Lithotrophic Iron-Oxidizing Bacteria Isolated from the Wetland-Plant Rhizosphere

Scott C. Neubauer,1* David Emerson,2 and J. Patrick Megonigal1

Smithsonian Environmental Research Center, Edgewater, Maryland,1 American Type Culture Collection, Manassas, Virginia2

Received 1 March 2002/ Accepted 7 May 2002

Batch cultures of a lithotrophic Fe(II)-oxidizing bacterium, strain BrT, isolated from the rhizosphere of a wetland plant, were grown in bioreactors and used to determine the significance of microbial Fe(II) oxidation at circumneutral pH and to identify abiotic variables that affect the partitioning between microbial oxidation and chemical oxidation. Strain BrT grew only in the presence of an Fe(II) source, with an average doubling time of 25 h. In one set of experiments, Fe(II) oxidation rates were measured before and after the cells were poisoned with sodium azide. These experiments indicated that strain BrT accounted for 18 to 53% of the total iron oxidation, and the average cellular growth yield was 0.70 g of CH2O per mol of Fe(II) oxidized. In a second set of experiments, Fe(II) was constantly added to bioreactors inoculated with live cells, killed cells, or no cells. A statistical model fitted to the experimental data demonstrated that metabolic Fe(II) oxidation accounted for up to 62% of the total oxidation. The total Fe(II) oxidation rates in these experiments were strongly limited by the rate of Fe(II) delivery to the system and were also influenced by O2 and total iron concentrations. Additionally, the model suggested that the microbes inhibited rates of abiotic Fe(II) oxidation, perhaps by binding Fe(II) to bacterial exopolymers. The net effect of strain BrT was to accelerate total oxidation rates by up to 18% compared to rates obtained with cell-free treatments. The results suggest that neutrophilic Fe(II)-oxidizing bacteria may compete for limited O2 in the rhizosphere and therefore influence other wetland biogeochemical cycles.

* Corresponding author. Mailing address: Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, MD 21037. Phone: (443) 482-2355. Fax: (443) 482-2380. E-mail: neubauer{at}serc.si.edu.

Applied and Environmental Microbiology, August 2002, p. 3988-3995, Vol. 68, No. 8
0099-2240/02/$04.00+0     DOI: 10.1128/AEM.68.8.3988-3995.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Blothe, M., Roden, E. E. (2009). Composition and Activity of an Autotrophic Fe(II)-Oxidizing, Nitrate-Reducing Enrichment Culture. Appl. Environ. Microbiol. 75: 6937-6940 [Abstract] [Full Text]  
  • Zhang, G., Dong, H., Jiang, H., Kukkadapu, R. K., Kim, J., Eberl, D., Xu, Z. (2009). Biomineralization associated with microbial reduction of Fe3+ and oxidation of Fe2+ in solid minerals. American Mineralogist 94: 1049-1058 [Abstract] [Full Text]  
  • Blothe, M., Roden, E. E. (2009). Microbial Iron Redox Cycling in a Circumneutral-pH Groundwater Seep. Appl. Environ. Microbiol. 75: 468-473 [Abstract] [Full Text]  
  • Omoregie, E. O., Mastalerz, V., de Lange, G., Straub, K. L., Kappler, A., Roy, H., Stadnitskaia, A., Foucher, J.-P., Boetius, A. (2008). Biogeochemistry and Community Composition of Iron- and Sulfur-Precipitating Microbial Mats at the Chefren Mud Volcano (Nile Deep Sea Fan, Eastern Mediterranean). Appl. Environ. Microbiol. 74: 3198-3215 [Abstract] [Full Text]  
  • Grathoff, G. H., Baham, J. E., Easterly, H. R., Gassman, P., Hugo, R. C. (2007). MIXED-VALENT Fe FILMS ('SCHWIMMEISEN') ON THE SURFACE OF REDUCED EPHEMERAL POOLS. Clays and Clay Minerals 55: 635-643 [Abstract] [Full Text]  
  • Weiss, J. V., Emerson, D., Megonigal, J. P. (2005). Rhizosphere Iron (III) Deposition and Reduction in a Juncus effusus L.-Dominated Wetland. Soil Sci. 69: 1861-1870 [Abstract] [Full Text]  
  • Benzerara, K., Yoon, T. H., Menguy, N., Tyliszczak, T., Brown, G. E. Jr. (2005). Nanoscale environments associated with bioweathering of a Mg-Fe-pyroxene. Proc. Natl. Acad. Sci. USA 102: 979-982 [Abstract] [Full Text]  
  • Jin, Q., Bethke, C. M. (2003). A New Rate Law Describing Microbial Respiration. Appl. Environ. Microbiol. 69: 2340-2348 [Abstract] [Full Text]  
  • Frankel, R. B., Frankel, R. B., Bazylinski, D. A. (2003). Biologically Induced Mineralization by Bacteria. Reviews in Mineralogy and Geochemistry 54: 95-114 [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»