What is the difference between a chemoheterotroph like listeria monocytogenes and a photoheterotroph?

The difference between the two (a chemoheterotroph and a photoheterotroph) is that the chemoheterotroph use organic molecules as an energy source while photoheterotroph use as the light. The energy source of chemoheterotroph is metabolizing organic matter of dead organisms such as bacteria and fungi while the energy source of photooheterotroph is sunlight such as purple and green photosynthetic bacteria.

The difference between these organisms lies in where they get their energy from. A chemoheterotroph gets energy from chemical bonds, while a photoheterotroph gets energy from photons. So photoheterotroph's get their energy from light. A chemoheterotroph gets it's energy from external sources like glucose.