sterolibacterium denitrificans sterolibacterium denitrificans sterolibacterium denitrificans is a gram-negative, rod-shaped motile bacterium with a single polar flagellum from the genus of rhodocyclus. sterolibacterium denitrificans scientific classification domain: bacteria phylum: pseudomonadota class: betaproteobacteria order: nitrosomonadales family: sterolibacteriaceae genus: sterolibacterium species: s. denitrificans binomial name sterolibacterium denitrificanstarlera and denner 2003 type strain atcc baa-354, chol-1s, chol1, dsm 13999