Photoheterotroph

Photoheterotrophs (Gk: photo = light, hetero = (an)other, troph = nourishment) are heterotrophic organisms that 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. They use compounds such as carbohydrates, fatty acids and alcohols as their organic "food". Examples are purple non-sulfur bacteria, green non-sulfur bacteria and heliobacteria.