scytonemine
Scytonemin is a yellowish-brown pigment produced by many species of cyanobacteria. It is a type of scytonemin, a class of extracellular polymeric substances (EPS) that accumulate in the sheaths of cyanobacterial cells. The pigment plays a significant role in protecting cyanobacteria from environmental stressors, particularly UV radiation.
The chemical structure of scytonemin is characterized by a planar, fused-ring system that efficiently absorbs ultraviolet
Scytonemin is often visible as a colored sheath or layer surrounding the cyanobacterial colonies, giving them