azoarcus olearius azoarcus olearius azoarcus olearius is a species of bacteria. it is a nitrogen-fixing bacteria. its cells are gram-negative, motile and rod-shaped, surrounded by a thin capsule. its type strain is dqs-4t (=bcrc 80407t =kctc 23918t =lmg 26893t). azoarcus olearius scientific classification domain: bacteria phylum: pseudomonadota class: betaproteobacteria order: rhodocyclales family: rhodocyclaceae genus: azoarcus species: azoarcus oleariuschen et al., 2013