A. addita A. genovensis A. hispanica A. litorea A. macleodii A. marina A. simiduii A. stellipolaris A. tagae Alteromonas is a genus of Pseudomonadota[1] found in sea water, either in the open ocean or in the coast.

Its cells are curved rods with a single polar flagellum.

The etymology of the genus is Latin alter -tera -terum, another, different; monas (μονάς), a noun with a special meaning in microbiology used to mean unicellular organism; to give Alteromonas, another monad[2] Members of the genus Alteromonas can be referred to as alteromonads (viz.

The genus was described by Baumann et al. in 1972,[3] but was emended by Novick and Tyler 1985 to accommodate Alteromonas luteoviolacea (now Pseudoalteromonas luteoviolacea),[4] Gauthier et al. 1995, who split the genus in two (Pseudoalteromonas)[5] and Van Trappen et al. in 2004 to accommodate Alteromonas stellipolaris.

[6] "Alteromonas-like sub-group" has been identified by microbial culture, metagenomics, and FISH-probe microscopy in the typhlosole sub-organ of the shipworm cecum as a symbiont digesting lignin.