Desulfovibrionales
Desulfovibrionales are a taxonomic order of bacteria belonging to the Phylum 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.