Here, we present a draft genome in the order Rhizobiales and family Devosiaceae. This draft genome comes from an enrichment of a heterocystous, cyanobacterial diazotroph (HetDA) that was originally living in association with Trichodesmium species. This Rhizobiales organism is proposed to be an anoxygenic phototroph capable of dissimilatory nitrate reduction to ammonia (DNRA).