Properties of microbial photosynthetic systems Property cyanobacteria Green and Purple nonsulfur purple bacteria bacteria Photo-pigment Chlorophyll Bcteriochlorophyll Bcteriochlorophyll O production Y No Electron donors H2O H2 H2S. s H2 h2S. s Carbon source CO2 CO2 Organic/CO Primary products ATP+ NADPH ATP ATP of energy conversionProperty 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