TAXONOMY: cellular organisms -> Bacteria -> Proteobacteria -> delta/epsilon subdivisions -> Deltaproteobacteria -> Desulfovibrionales
The Desulfovibrionales are an order of Proteobacteria, with four families. Like all Proteobacteria, they are Gram-negative. The majority are sulfate-reducing, with the exception of Lawsonia and Bilophila. All members of this order are obligately anaerobic. Most species are mesophilic, but some are moderate thermophiles. Most sulfate-reducing bacteria can also reduce other oxidized inorganic sulfur compounds, such as sulfite, thiosulfate, or elemental sulfur (which is reduced to hydrogen sulfide). In addition, there are sulfate-reducing bacteria that can reduce fumarate, nitrate and nitrite, iron (Fe(III)) and some other metals, dimethyl sulfoxide and even oxygen.