| Azoarcus anaerobius
Bacteria, Proteobacteria, Herbaspirillum, Betaproteobacteria, Azospirillum
Azoarcus is a genus of nitrogen-fixating bacteria. Species in this genus are usually found in contaminated water, as they are involved in the degradation of some contaminants, commonly habitating in soil. These bacteria have also been found growing in the endophytic compartment (inside the plant between the living cells) of some rice species and other grasses.