Three  anoxygenic photosynthetic bacteria, DS-1, DS-4 and Cas-13, have been examinated  for  the
morphological and physiological  properties. All strains were rod-shape cells with  a swollen terminal  end
Gram  negative, motile, non-halophilic, non-alkalophilic  and non-acidophilic,  and capable of utilizin
benzoate aerobically and photo-anaerobically. Sequence analysis of part of 16S rRNA genes showed that DS
1 and Cas-13 were closely related to Rhodopseudomonas palustris Strain 7 with a similarity of 97%, wherea
DS-4 may not be closely related to the former two strains with a similarity of 78% based on the constructe
phylogenic  tree. Spectral analysis indicated that the three  bacteria  had  bacteriochlorophyl  a  and norma
spirilloxanthin series.
Growth in medium enriched with vitamin and supplemented with benzoate as their sole C-sources wa
better than in medium without vitamin. Benzoate degradation in medium with vitamin was accelerated. Th
ability  to grow on benzoate without added vitamins indicated  that  the bacteria were able to synthesize  the
own vitamins.