Bacteroides ureolyticus is a species in the bacterial genus of Gram-negative, obligately anaerobic bacteria. Bacteroides species are non-endospore-forming bacilli, and may be either motile or non-motile, depending on the species. The DNA base composition is 40-48% GC. Unusual in bacterial organisms, Bacteroides membranes contain sphingolipids. They also contain meso-diaminopimelic acid in their peptidoglycan layer.