In places with extreme solar irradiation reside microalga Coelastrella rubescens; thus it must contain a myriad of compounds to protect itself. 

A recent study illustrated the assemblage of photoprotective compounds in C. rubescens. For the study, the cells were exposed to immense visible light and UV-A and the ability of hydrophilic and hydrophobic extracts from the cells to absorb radiation was investigated.  

• Coelastrella showed an accumulation of diverse carotenoids that absorbed visible light in the blue-green range of the spectrum and mycosporine-like amino acids (MAA) that engrossed the UV-A. Thus, the occurrence of MAA in Coelastrella was demonstrated. 
• Also, 2 new MAA (coelastrin A and coelastrin B), were determined.
• The development of hydrophobic subcompartments under the high light and UV-A exposition was noted. Further, the presence of sporopollenin-like compounds in the cell wall and autophagy-like processes might be responsible for decreasing sunlight absorption by cells, along with inducible sunscreen accumulation.

These results indicate that C. rubescens NAMSU R1 reserves a broad range of valuable photoprotective compounds in response to UV-A and visible light irradiation, indicating this strain to be a potential producer for biotechnology.

Source: Zaytseva A, Chekanov K, Zaytsev P, et al. Sunscreen effect exerted by secondary carotenoids and mycosporine-like amino acids in the aeroterrestrial chlorophyte Coelastrella rubescens under high light and UV-A irradiation. Plants (Basel). 2021 ;10(12):2601.