Cells are ovoid or rod-shaped, motile by polar flagella or non-motile, divide by binary fission or budding, may produce capsules and slime, and may form chains of cells. Gram negative; belong to the Alphaproteobacteria. Phototrophically grown cells form vesicular or lamellar internal photosynthetic membranes. The color of phototrophic cultures is yellow-green to yellow-brown, while aerobic cultures are pink to red. Photosynthetic pigments are bacteriochlorophyll a (esterified with phytol) and carotenoids of the spheroidene series. Ubiquinone 10 is the major quinone. Major fatty acids are C18 and C16 saturated and monounsaturated fatty acids with C18:1 as predominant component. The mol% G + C of the DNA is: 64.4–73.2. Type species: Rhodobacter capsulatus
Microbial Abundance Data: Rhodobacter (Percent of total population with standard deviation [PMID: 22698087])