ROSEOBACTER-LITORALIS GEN-NOV, SP-NOV, AND ROSEOBACTER-DENITRIFICANS SP-NOV, AEROBIC PINK-PIGMENTED BACTERIA WHICH CONTAIN BACTERIOCHLOROPHYLL-A

The new genus Roseobacter, with the two new species Roseobacter litoralis and Roseobacter denitrificans, is proposed for certain aerobic heterotrophs containing bacteriochlorophyll a. R. denitrificans was previously called Erythrobacter sp. OCH114. Members of Roseobacter contain spheroidenone as a major carotenoid, do not synthesize bacteriochlorophyll anaerobically, but show aerobic phototrophic activity. Cells are ovoid or rodshaped, motile by subpolar flagella, and require biotin, nicotinic acid, thiamine and Na+ ion. In vivo absorption spectra show a large band at 805-7nm, and a smaller band at 868-73 nm in the near infrared region. R. denitrificans dissimilatorily reduces nitrate, whereas R. litoralis does not.