TAXONOMY: Bacteria -> Proteobacteria -> delta/epsilon subdivisions -> Deltaproteobacteria -> Desulfovibrionales -> Desulfovibrionaceae -> Desulfovibrio
'Desulfovibrio' is a genus of Gram-negative sulfate-reducing bacteria. Desulfovibrio species are commonly found in aquatic environments with high levels of organic material, as well as in water-logged soils, and form major community members of extreme oligotrophic habitats such as deep granitic fractured rock aquifers. Like other sulfate-reducing bacteria, Desulfovibrio was long considered to be obligately anaerobic. This is not strictly correct: while growth may be limited, these bacteria can survive in O2-rich environments. These types of bacteria are known as aerotolerant. Some Desulfovibrio species have in recent years been shown to have bioremediation potential for toxic radionuclides such as uranium by a reductive bioaccumulation process. Desulfovibrio species are more common in autistic subjects than in controls. The controversial idea is that these anaerobic bacilli may actually be selected during the treatment of common childhood infections because of their resistance to antimicrobial agents such as cephalosporins. Enriched in type II diabetics.
Curved or occasionally straight rods, sometimes sigmoid or spirilloid, 0.5–1.5 × 2.5–10.0 μm. The morphology is influenced by age and environment; descriptions refer to freshly grown cultures in anoxic sulfate media. Spore formation is absent. Gram negative. Motile by means of a single or lophotrichous polar flagella. Obligately anaerobic growth in pure cultures. Possess mainly a respiratory type of metabolism with sulfate or other sulfur compounds as the terminal electron acceptors, being reduced to H2S; however, the metabolism is sometimes fermentative. Media containing a reducing agent are required for growth. In a few cases, a vitamin requirement has been reported. Some species and subspecies are moderately halophilic. Optimal growth temperature, usually 25–35°C; upper limit normally 44°C. No thermophilic species have been reported. Thermophilic Desulfovibrio species formerly described have been reclassified and currently belong to the genera Thermodesulfovibrio and Thermodesulfobacterium. Chemoorganotrophic.
Most species oxidize organic compounds such as lactate incompletely to acetate, which cannot be oxidized further. Carbohydrates are utilized by few species. One species, D. inopinatus, can use hydroquinone as electron donor and carbon source for growth. Cells contain c-type cytochromes (such as c3) and usually b-type cytochromes. All members of the genus Desulfovibrio contain desulfoviridin. Hydrogenase is usually present. Strains of some species may show chemolithoheterotrophic growth, using H2 as electron donor and assimilating acetate and CO2, or yeast extract, as carbon sources. Gelatin is not liquefied. Nitrate is sometimes reduced to ammonia. Some species can reduce oxygen or metal ions, but growth has never been observed with these electron acceptors in pure cultures. Molecular nitrogen is sometimes fixed. Species generally show some degree of antigenic cross reaction. Habitats: anoxic mud of fresh and brackish water and marine environments; intestines of animals; manure and feces. The mol% G + C of the DNA is: 46.1–61.2.Type species: Desulfovibrio desulfuricans
This genus contains microbial species that can reside in the human gastrointestinal tract. [PMC 4262072] Decreased in metabolic disorders.