A Microbial Biorealm page on the genus Desulfococcus
Higher order taxa:
Bacteria; Proteobacteria; delta/epsilon subdivisions; Deltaproteobacteria; Desulfobacterales; Desulfobacteraceae
Desulfococcus biacutus, Desulfococcus multivorans, Desulfococcus oleovorans, Desulfococcus sp. DSM 8541
Description and Significance
Desulfococcus group is cultivated bacteria as well as Desulfosarcina. They can completely oxidize acetate by using sulfate as electron acceptor under anoxic condition. They are involved in Chemoautotrophs, anaerobic, thermophilic and mesophilic bacteria. In coastal marine sediments, over 50% of carbon is decomposed by sulfate-reducing bacteria including Desulfococcus. Also, they play an important role in the cycling of sulfur compounds of in sea water(Das et al 2006).
The genome of Desulfococcus oleovorans is completely sequenced. Desulfococcus oleovorans is a sulfate-reducing δ-proteobacterium. The G+C content of the 16S ribosomal DNA gene of Desulfococcus oleovorans is 63%(So and Young 1999). Strain Hxd3 of Desulfococcus oleoborans was isolated from an oil tank. Desulfococcus oleoborans can use alkanes from C12 to C20 due to strain Hxd3, they have best growth rate in the range form C15 to C18.
Cell Structure and Metabolism
Desulfococcus are sphere shape bacteria. Desulfococcus oleovorans can use alkanes from C12 to C20, 1-hexadecene, 1-hexadecanol, 2-hexadecanol, palmitate and stearate as electron donors and sulfate as terminal electron acceptor for the growth(Aeckersberg et al., 1991). This indicates that Desulfococcus oleovorans play an crucial role in the accumulation of sulfide(Rueter et al., 1994). Also, Desulfococcus have the capability of detoxifying mercury compounds. Desulfococcus can methylate mercury(Macalady et al 2000)
Desulfococcus groups are one of the most active population in coastal sediments. In general, sulfate-reducing bacteria group are considered as obligate anaerobes, but some SRB can survive in the presence of oxygen. For example, Duslfobulbus, Desulfobacter and Desulfotomaculum species are predominant in the lower part of sediments, while the Desulfococcus and Deuslfovibrio groups predominantly occupy in the upper part of the photo-oxic zone (Risatti et al, 1994). However, Desulfococcus use energy only for maintenancein oxic condition. They can grow only at anoxic condition so that they are considered as anaerobic bacteria.
1. Ravenschlag, K. Sahm, K. Knoblauch, C. Jørgensen, , B.B., and Amann, , R. ( 2000) Community structure, cellular rRNA content, and activity of sulfate-reducing bacteria in marine Arctic sediments. Appl Environ Microbiol 66: 3592– 3602.
5. Macalady,J.L., Mack,E.E., Nelson,D.C., and Scow,K.M. ( 2000) Sediment microbial community structure and mercury methylation in mercury-polluted Clear Lake, California. Appl Environ Microbiol 66: 1479– 1488.
Edited by student of Kate Scow