(1) Photoheterotrophs` (or `photoorganotrophs`) are heterotrophic organisms which use light for energy, but cannot use carbon dioxide as their sole carbon source. Consequently, they use organic compounds from the environment to satisfy their carbon requirements. Examples are purple non-sulfur bacteria, green non-sulfur bacteria and heliobacteria.
(2) An organism that depends on light for most of its energy and principally on organic compounds for its carbon. … Compare: photoautotroph, photolithotroph, phototroph.