**3.7 Photoinhibition**

In some cyanobacteria, photoinhibition light conditions trigger the synthesis of photoprotective pigments. For example, intense radiation or UV radiation, accumulate mycosporine-like amino acids and scytonemins [30, 42]. Cyanobacteria, like *Nodularia* sp., *Euhalothece* sp. *Microcoleus* sp., and *Scytonema hofmanii* [43, 44] possess bilin photoreceptors, Cphs and CBCRs. These photosensitive receptors facilitate photobiological reactions by sensing and delivering signaling compounds.
