Rhodobium is a genus of purple non-sulfur bacteria. The cells are rod-shaped and reproduce by budding, as in many other members of the Rhizobiales. RNA trees separate it from the others, however, and it is given its own family. R. orientis, the type species, was isolated from seawater in 1995. It is capable of photosynthetic hydrogen production via the nitrogenase enzyme.
Hiraishi A, Urata K, Satoh T. (1995). A new genus of marine budding phototrophic bacteria, Rhodobium gen. nov., which includes Rhodobium orientis sp. nov. and Rhodobium marinum comb. nov. International Journal of Systematic and Evolutionary Microbiology 45: 226-234.