Occurrence of bacteriochlorophyll a P and a gin strains of all species of the Rhodospirillaceae

The bacteriochlorophylls a of 60 strains belonging to 13 different species of the purple nonsulfur bacteria (Rhodospirillaceae) were studied with respect to the nature of the esterifying alcohol. The new bacteriochlorophyll aGg containing all-trans-geranylgeraniol is the main bacteriochlorophyll in all strains of Rhodospirillum rubrum. Rhodospirillum photometricum contains the new and the classical bacteriochlorophyll aP (phytol as esterifying alcohol) in nearly equal amounts. The strains of all other species contain the classical bacteriochlorophyll aP.