Desulfovibrio desulfuricans
| Desulfovibrio desulfuricans | ||||||||||||
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The bacterium in an X-ray micrograph. |
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| Desulfovibrio desulfuricans | ||||||||||||
| ( Beijerinck 1895) Kluyver & van Niel 1936 |
Desulfovibrio desulfuricans is a sulfate-reducing bacterium . It is chemolithoheterotroph and chemoorganoheterotroph , obligately anaerobic , gram-negative , contains desulfovidrin and does not form spores . The simple, polar flagellated, curved rods are 3–5 µm long and have a diameter of 0.5–1 µm. The optimum growth is at temperatures of 34 to 37 ° C and pH values of 6.6-7.5. Desulfovibrio desulfuricans was found in freshwater and seawater, but especially in polluted waters and soils with a high proportion of organic matter.
This bacterium is blamed for the large deposits of elemental sulfur in Texas and Louisiana, where limestone and elemental sulfur were found instead of the extensive original gypsum deposits . The limestone has the crystal form of gypsum. The carbon of the limestone and the elementary sulfur are of biogenic origin, as was confirmed by isotope analyzes. Furthermore, the presence of deposited petroleum in these rocks speaks for the biogenic formation of these layers.
The bacteria have the ability to change the pH value in the microenvironment, so that they cause an over-saturation of calcium and carbonate ions and thus a precipitation of calcium carbonate (limestone formation).
The restoration of marble statues was suggested as an application of this bacterium after a field experiment . The field experiment showed that the anaerobic bacterium colonized the surface of weathered marble statues and itself created the living conditions required to convert the gypsum formed by the effects of acid rain back into lime. The exact biochemical processes of this calcification have not yet been clarified.
The DNA of the bacterium was completely sequenced in 1997. The bacterium represents a danger for oil pipelines and tanks because of the corrosive effect of its metabolism. The formation of putrid water in the drinking water tanks of ships can also be attributed to these bacteria.
literature
- RM Atlas, AN Chowdhury, KL Gauri: Microbial Calcification of Gypsum-Rock and Sulfated Marble . In: Studies in Conservation , Vol. 33, No. 3, 1988, pp. 149-153
- DG Kirkland, E. Robert: Origin of limestone buttes, gypsum plain, Culberson Co., Texas . In: Amer. Assoc. Petrol. Geol. Bull. Vol. 60, 1976, pp. 2005-2018.
- LP Miller: Rapid formation of high concentrations of hydrogen sulfide by sulfate reducting bacteria . In: Contrib. Boyce Thompson Inst. Vol. 15, 1949, pp. 437-465.
- HW Feeley, JL Kulp: Origin of the Gulf Coast salt-dome sulfur deposits . In: Am. Assoc Petrol. Bull. Vol. 41, 1957, pp. 1802-1853.
See also
Individual evidence
- ↑ Desulfovibrio desulfuricans G20 . genome.jgi-psf.org. Retrieved July 10, 2011.
Web links
Pubget Medical Subject Headings (MESH) A list of recent research reports on Desulfovibrio desulfuricans .