Photoautotroph Algae. Cyanobacteria CO2+H2O Light+ Chlorophy+(CH20)+O2 Purple and green bacteria CO2+2H2S Light t bacteriochlorophyll,(CH20)+ H2O+ 2S Photoheterotroph Purple nonsulfur bacteria(rhodospirillum CO2+2CH3CHOHCH3 Light bacteriochlorophyll,(CH20) +H2o+2CH3 COCH3Algae, Cyanobacteria CO2 + H2O Light + Chlorophyll （CH2O） +O2 Purple and green bacteria CO2 + 2H2S Light + bacteriochlorophyll（CH2O） + H2O + 2S Purple nonsulfur bacteria (Rhodospirillum) CO2 + 2CH3CHOHCH3 Light + bacteriochlorophyll（CH2O） + H2O + 2CH3COCH3 Photoautotroph: Photoheterotroph: