Pseudonocardia
From ActinoBase
Pseudonocardia are filamentous actinomycetes with ~6Mbp circular genomes, best known as vertically transmitted mutualists of fungus-growing attine ants.
Further reading:
Li H, Sosa-Calvo J, Horn HA, Pupo MT, Clardy J, Rabeling C, Schultz TR and Currie CR (2018). Convergent evolution of complex structures for ant–bacterial defensive symbiosis in fungus-farming ants. https://www.ncbi.nlm.nih.gov/pubmed/30282739
Holmes N, Innocent T, Heine D, Worsley S, Findlay K, Murrell J.C., Wilkinson B, Boomsma JJ and Hutchings MI (2016). Genome analysis of two Pseudonocardia phylotypes associated with Acromyrmex leafcutter ants reveals their biosynthetic potential. Front Microbiol. 7:2073