Geobacter sulfurreducens

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Geobacter sulfurreducens
Geobacter sulfurreducens.TIF

Geobacter sulfurreducens

Systematics
Department : Proteobacteria
Class : Deltaproteobacteria
Order : Desulfuromonadales
Family : Geobacteraceae
Genre : Geobacter
Type : Geobacter sulfurreducens
Scientific name
Geobacter sulfurreducens
Caccavo et al. 1995

The Proteobacterium Geobacter sulfurreducens is a Geobacter species that belongs to the sulfur-reducing group of the order Desulfuromonadales .

description

The bacteria are gram-negative, immobile rods that are 2 to 3 × 0.5 µm in size. No spores are formed. The cells contain cytochrome c and still grow in media with a salt concentration half that of seawater, i.e. 1.75%. Their optimum growth is between 30 and 35 ° C.

They are strictly anaerobic and chemoorganotrophic , which means that they get their energy from organic substances. They oxidize acetate with iron (III), sulfur , cobalt (III), fumarate , or malate as the electron acceptor . Also, hydrogen is used as the electron donor used for the iron (III) reduction.

G. sulfurreducens is the first isolated bacterium that couples the oxidation of acetate or hydrogen to iron (III) reduction.

Species delimitation

Phylogenetically, G. sulfurreducens is most closely related to Geobacter metallireducens . Both are metal-reducing bacteria, but G. sulfurreducens can not reduce manganese (IV) in comparison, but can use hydrogen as an electron donor. G. sulfurreducens also cannot use alcohols or aromatic compounds such as phenols as electron donors.

Habitat

G. sulfurreducens was prepared from surfaces sediments of a trench in Norman ( Oklahoma ) was isolated, which with hydrocarbons contaminated. Acetate acted as an electron donor and trivalent iron as an electron acceptor [ iron phosphate in the form of iron (III) -containing diphosphate ].

Historical

The first isolation of microbes of the later genus Geobacter took place in 1987 by Derek Lovley from sediments of the Potomac River . The genus Geobacter was identified in 1993 together with its type species G. metallireducens by Lovley et al. and confirmed in 1995. In 1994 Caccavo et al. a description of Geobacter sulfurreducens as a new species, also confirmed in 1995.

Applications

In 2011, a working group led by the American physicist Mark Tuominen demonstrated that a thin film of G. sulfurreducens conducts electrical current with a conductivity of approx. 5 millisiemens per cm. Nanofilaments that can be obtained from bacteria show a similar electrical conductivity . The conductivity of the material is retained over several centimeters and thus resembles the electrical properties of synthetic metallic nanostructures. The scientists interpreted their findings to mean that G. sulfurreducens produces proteins that conduct electricity, which could be of great importance for the construction of electronic components on the nanoscale.

literature

  • F. Caccavo, DJ Lonergan, DR Lovley, M. Davis, JF Stolz, MJ McInerney: Geobacter sulfurreducens sp. nov., a hydrogen- and acetate-oxidizing dissimilatory metal-reducing microorganism. In: Applied and environmental microbiology. Volume 60, Number 10, October 1994, pp. 3752-3759, PMID 7527204 , PMC 201883 (free full text).

Individual evidence

  1. ↑ a b F. Caccavo, DJ Lonergan, DR Lovley, M. Davis, JF Stolz, MJ McInerney: Geobacter sulfurreducens sp. nov., a hydrogen- and acetate-oxidizing dissimilatory metal-reducing microorganism. In: Applied and environmental microbiology. Volume 60, Number 10, October 1994, pp. 3752-3759, PMID 7527204 , PMC 201883 (free full text).
  2. ↑ Derek R. Lovley, John F. Stolz, Gordon L. Nord, Elizabeth JP Phillips: Anaerobic production of magnetite by a dissimilatory iron-reducing microorganism. In: Nature. 330, 1987, p. 252, doi : 10.1038 / 330252a0 .
  3. ↑ DR Lovley, SJ Giovannoni, DC White, JE Champine, EJ Phillips, YA Gorby, S. Goodwin: Geobacter metallireducens gen. Nov. sp. nov., a microorganism capable of coupling the complete oxidation of organic compounds to the reduction of iron and other metals. In: Archives of microbiology. Vol. 159, Number 4, 1993, pp. 336-344, PMID 8387263 .
  4. ↑ a b IUMS : Validation of the Publication of New Names and New Combinations Previously Effectively Published Outside the IJSB: List No. 54. In: International Journal of Systematic Bacteriology. 45, 1995, p. 619, doi : 10.1099 / 00207713-45-3-619 .
  5. ↑ Malvankar NS, Vargas M, Nevin KP, Franks AE, Leang C, Kim BC, Inoue K, Mester T, Covalla SF, Johnson JP, Rotello VM, Tuominen MT, Lovley DR: Tunable metallic-like conductivity in microbial nanowire networks. In: Nat Nanotechnol . From August 7, 2011. doi : 10.1038 / nnano.2011.119 . PMID 21822253

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