Dear student,
Characteristics of photosynthetic bacteria:-
1) They are capable of photosynthesis producing carbohydrate as the source of energy.
2) They contain photosynthetic pigment called bacteriochlorophyll.
3) There are three groups of photosynthetic bacteria Chlorobiacae (green bacteria, uses sulphur as electron donor), chromatiacae (purple bacteria, uses sulphur as electron donor), rhodospirillacae (purple bacteria, uses hydrogen gas as electron donor).
Regards