[2] Spheroidene is bound to the type II photosynthetic reaction center of purple bacteria, and together with the bacteriochlorophyll forms part of the light-harvesting complex.

In this manner the reaction center is able to harness more of the visible light spectrum than would be possible with bacteriochlorophyll alone.

This quenching helps to prevent the formation of harmful singlet oxygen.

[4][5] Other functions of spheroidene may include scavenging of singlet oxygen, nonradiative dissipation of excess light energy, and structural stabilization of the photosystem proteins.

[6] The proteins involved in spheroidene biosynthesis are encoded by a gene cluster.