Property cyanobacteria Green and purple bacteria Purple nonsulfur bacteria Photo - pigment Chlorophyll Bcteriochlorophyll Bcteriochlorophyll O2 production Yes No No Electron donors H2O H2, H2S, S H2, H2S, S Carbon source CO2 CO2 Organic / CO2 Primary products of energy conversion ATP + NADPH ATP ATP Properties of microbial photosynthetic systemsProperty cyanobacteria Green and purple bacteria Purple nonsulfur bacteria Photo - pigment Chlorophyll Bcteriochlorophyll Bcteriochlorophyll O2 production Yes No No Electron donors H2O H2, H2S, S H2, H2S, S Carbon source CO2 CO2 Organic / CO2 Primary products of energy conversion ATP + NADPH ATP ATP Properties of microbial photosynthetic systems