Desulfobacter

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A Microbial Biorealm page on the genus Desulfobacter

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Classification

Higher order taxa:

Bacteria; Proteobacteria; delta/epsilon subdivisions; Deltaproteobacteria; Desulfobacterales; Desulfobacteraceae

Species:

NCBI: Taxonomy Genome

Description and Significance

"Desulfobacter" is a mesophilic gram-negative genera that is capable of oxidizing organic substrate completely to CO2. Desulfobacter is mainly common in brackish and marine environemnt (1). The genus "desulfobacter" includes acetateutelizing sulphate-reducing bacteria. 10 Methyl 16:0 is an unusual bacterial phospholipid fatty acids (PLFA) characteristic of Desulfobacter-type sulphate-reducing bacteria and could be used as a biomarker for these bacteria [21,30].

21-Dowling, N.J., Widdel, F. and White, D.C. (1986) Comparison of the phospholipid ester-linked fatty acid biomarkers of acetate-oxidising sulphate-reducers and other sulphide-forming bacteria. J. Gen. Microbiol. 132,1815-1825.

30-Dowling, N.J., Nichols, P.D. and White, D.C. (1988)Phospholipid fatty acid and infra-red spectroscopic analysis of a sulfate-reducing consortium. FEMS Microbiol.Ecol. 53, 325-334

1-Lary L. Barton Biotechnology handbooks. Vol. 8-Sulfate reducing bacteria. 1995 Plenum Press, New York.

This rod-shaped bacterium is identified as anaerobically growing, motile organism. Desulfovibrio is known as a sulfate reducing bacterium, which has put it to the forefront of biological research. Because of its metal corroding ability, which has consequently led to numerous health and safety concerns in industry, a means to neutralize and better understand Desulfovibrio species is the goal of research on Desulfovibrio (ITQB). The organism however also shows potential for bioremediation, in that it may undergo anaerobic conversion of pollutants in the soil.

Genome Structure

Cell Structure and Metabolism

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D. variabilis contains significant quantities of AEG-P (top), and almost 20% of the alkyl-glycerol bond is present as DPG lipids, also known as "cardiolipin" (bottom). Note that the DPGs contain either ether or ester linkages in the core lipids.Sturt et al


Sulfate reducers have a wide range of cellular morphologies, including rods, vibrios, ovals, spheres and even tear-dropped or onion shaped cells. Some are motile, others are not. Most sulfate-reducing bacteria are mesophilic, but a few thermophiles are known. Desulfosarcina variabilis is mesophilic, and contains bacterial core lipids (see images on left). The dominant phospholipid headgroups in D. variabilis are Phosphoethanolamine PE (48%) and Phosphoglycerol PG (33%). One study has found that Desulfosarcina variabilis solely contained n-hexadecyl ether side chains. For more information on tetraether lipids found in Archaea, click here.


Ecology

Although sulfate reduction is thought to be an anaerobic process, sulfate-reducing bacteria (SRB) are also important in aerobic environments if they can proliferate in anaerobic zones. For example, in marine sediments and in aerobic wastewater treatment systems, sulfate reduction accounts for up to 50% of the mineralization of organic matter. Furthermore, sulfate reduction strongly stimulates microbially enhanced corrosion of metals.

The Plum Island Estuary Microbial Observatory (PIMO), located at the Plum Island Estuary LTER site in coastal Massachusetts, identifies prokaryotes in salt marsh sediments and plankton and determines their role in controlling major ecosystem processes. Among SRBs identified, relatives of Desulfosarcina variabilis and Desulfobacterium anilini were found to be persistent in the sediment.

References

Arches, specifically p.10 populations and methods.PDF here.

Microbiology Textbook. Copyright, Timothy Paustian© 1999-2004.

PIMO Database.

Rutters H, Sass H, Cypionka H, Rullkotter J. "Monoalkylether phospholipids in the sulfate-reducing bacteria Desulfosarcina variabilis and Desulforhabdus amnigenus." Arch Microbiol. 2001 Dec;176(6):435-442. Epub 2001 Sep 19.

Santegoeds, Cecilia M.; Timothy G. Ferdelman, Gerard Muyzer, and Dirk de Beer. "Structural and Functional Dynamics of Sulfate-Reducing Populations in Bacterial Biofilms." Appl Environ Microbiol. 1998 October; 64(10): 3731–3739. Copyright © 1998, American Society for Microbiology.

Sturt, Helen F.; Roger E. Summons, Kristin Smith, Marcus Elvert, and Kai-Uwe Hinrichs. "Intact polar membrane lipids in prokaryotes and sediments deciphered by high-performance liquid chromatography/electrospray ionization multistage mass spectrometry—new biomarkers for biogeochemistry and microbial ecology." Rapid Commun. Mass Spectrom. 2004; 18: 617–628.