Dissimilatory Metal Transformations by Microorganisms


There has been a dramatic increase in the understanding of the biological mechanisms underpinning metal transformations in the environment. The techniques used to gain a better understanding of these microbial processes will be discussed, along with an overview of assimilatory, dissimilatory and detoxification transformations of a range of metals and radionuclides.

Keywords: dissimilatory metal reduction; bioremediation; anaerobes; cytochromes; electron transfer

Figure 1.

Mechanism of uptake of Fe(III) by Gram‐negative bacteria. (Adapted from Andrews et al. .

Figure 2.

Mechanisms of reduction of insoluble Fe(III) oxides, via direct contact with the surface of the cell (top) or an extracellular electron shuttle (bottom). Adapted from Lloyd .

Figure 3.

Bacterial mercury resistance by proteins encoded by the mer operon.



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Further Reading

Frausto da Silva JJR and Williams RJP (1993) The Biological Chemistry of the Elements. Oxford, UK: Clarendon Press.

Lloyd JR, Chesnes J, Glasauer S et al. (2002) Reduction of actinides and fission products by Fe(III)‐reducing bacteria. Geomicrobiology Journal 19, 103–120.

Lloyd JR, Lovley DR and Macaskie LE (2003) Biotechnological application of metal‐reducing bacteria. Advances in Applied Microbiology 53: 85–128.

Mukhopadhyay R, Rosen B, Phung L and Silver S (2002) Microbial arsenic: from geocycles to genes and enzymes. FEMS Microbiology Reviews 26: 311.

Nies DH (2003) Efflux‐mediated heavy metal resistance in prokaryotes.FEMS Microbiology Reviews 27: 313–339.

Thamdrup B (2000) Bacterial manganese and iron reduction in aquatic sediments. Adv. Microbiology Ecology 16: 41–84.

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How to Cite close
Lloyd, Jonathan R(Jan 2006) Dissimilatory Metal Transformations by Microorganisms. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0000474]