The genus name is derived from the two-faced Roman god Janus, referring to the fact that the cells of the original strain could be rod-shaped or coccoid.

The type species of the genus, Janibacter limosus, was originally isolated from sludge from a wastewater treatment plant.

[3] Janibacter brevis was originally classified as a separate species, but was later found to be a heterotypic synonym of J.

[4][5] Colonies formed on agar by members of this genus are usually cream, white, or yellow pigmented.

[8] An unnamed Janibacter species caused an infection in a man with acute myeloid leukemia after receiving a bone marrow transplant.