Desulfobacteraceae

The Desulfobacteraceae are a family of Thermodesulfobacteriota. They reduce sulfates to sulfides to obtain energy and are strictly anaerobic. They have a respiratory and fermentative type of metabolism. Some species are chemolithotrophic and use inorganic materials to obtain energy and use hydrogen as their electron donor.

Biology and biochemistry

Morphology

Desulfobacteraceae vary widely in shape and size across the family. ''Desulfofaba'' are straight or slightly curved rods that range in size from 0.8 to 2.1 x 3.2-6.1 μm. Those in the genus ''Desulfobacterium'' are spherical or oval shaped and somewhat smaller, ranging in size from 0.9 to 1.3 x 1.5-3.0 μm or 1.5-2.0 x 2.0-2.5 μm. They stain Gram-negative and are not known to produce spores. Some species contain a single polar flagellum used for motility.

Genus and species of Desulfobacteraceae may only be definitively distinguished by analysis of 16S rDNA sequences, but certain genera may be determined through physiological characteristics alone. ''Desulfofrigus'' displays an optimal growth rate at very low temperatures compared to other sulfate reducing bacteria. It is also unable to grow in the presence of propionate.

Metabolism

Most species of Desulfobacteraceae use sulfur compounds as their main energy source. The most common source used is sulfate which, through metabolic processes, is reduced to sulfide. In an environment with little or no sulfate, sulfite or elemental sulfur may also be used and reduced into sulfide. In rare cases nitrate may also be used as a food source and reduced into ammonia. They have very efficient sulfate reduction rates (between 12 and 423 mu mol/dm³ day⁻¹) in optimal conditions.

Habitat

Desulfobacteraceae may be found in a range of locations but are most often found in saline and hypersaline waters including salt lakes and the ocean. They have also been found in polar ice in Antarctica. They may be found trapped within ice, floating within the water column, or living on or in other organisms such as sea sponges.

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI)

See also

* List of bacterial orders
* List of bacteria genera

References

;Notes

;Sources
* Foti, M., D. Y. Sorokin, B. Lomans, M. Mussman, E. E. Zacharova, N. V. Pimenov, J. G. Kuenen, and G. Muyzer. "Diversity, Activity, and Abundance of Sulfate-Reducing Bacteria in Saline and Hypersaline Soda Lakes." ''Applied and Environmental Microbiology'' 73.7 (2007): 2093–100.
* Garrity, George M.; Brenner, Don J.; Krieg, Noel R.; Staley, James T. (eds.) (2005). ''Bergey's Manual of Systematic Bacteriology'', Volume Two: ''The Proteobacteria, Part C: The Alpha-, Beta-, Delta-, and Epsilonproteobacteria.'' New York, New York: Springer. .
* Purcell, Alicia M. et al. “Microbial Sulfur Transformations in Sediments from Subglacial Lake Whillans.” ''Frontiers in Microbiology'' 5 (2014): 594. ''PMC''. Web. 20 Oct. 2015.

Desulfobacterales
{{Thermodesulfobacteriota-stub