Sun‐screening bioactive compounds mycosporine‐like amino acids in naturally occurring cyanobacterial biofilms: role in photoprotection

• Published in: Journal of applied microbiology 2015-09, Vol.119 (3), p.753-762
• Main Authors: Rastogi, R.P., Madamwar, D., Incharoensakdi, A.
• Format: Article
• Language: English
• Subjects: Amino acids; Amino Acids - analysis; Amino Acids - metabolism; Bacteria; Biofilms; Biofilms - radiation effects; Biosynthesis; Chromatography, High Pressure Liquid; Cyanobacteria; Cyanobacteria - chemistry; Cyanobacteria - metabolism; Cyanobacteria - physiology; Cyanobacteria - radiation effects; Cyclohexanones - analysis; Cyclohexanones - metabolism; Cyclohexylamines - analysis; Cyclohexylamines - metabolism; Escherichia coli; Glycine - analogs & derivatives; Glycine - analysis; Glycine - metabolism; induction; mycosporine‐like amino acids; photoprotection; Sunscreen; Sunscreening Agents - analysis; Sunscreening Agents - metabolism; Ultraviolet radiation; Ultraviolet Rays; UV radiation
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/jam.12879

Aims To investigate the occurrence of UV sunscreening biomolecules and their role in photoprotection in cyanobacterial biofilms growing in brightly lit habitats with high UV fluxes. Methods and Results High performance liquid chromatography with photodiode‐array and mass spectrometry revealed the presence of mycosporine‐like amino acids (MAAs) shinorine (λmax 334 nm, m/z 333), porphyra‐334 (λmax 334 nm, m/z 347), mycosporine‐glycine (λmax 310 nm, m/z 246) and palythinol (λmax 332 nm, m/z 303). Two unknown MAAs with λmax at 320 (m/z 289) and 329 nm (m/z 318) were also found. Biosynthesis of MAAs was found to increase with increase in exposure time under UV radiation. The MAAs from biofilms showed efficient radical scavenging activity as well as photoprotective potential on the survival of UV‐treated Escherichia coli cells. Conclusions Biosynthesis of photoprotectants is an important mechanism to prevent photodamage in Cyanobacteria. UV‐induction and photoprotective function of MAAs may facilitate them to perform important ecological functions under harsh environmental conditions. Significance and Impact of the Study There are very few reports on qualitative and quantitative characterization of different MAAs in cyanobacterial biofilms. Due to strong UV absorption and photoprotective function, MAAs may be used as an active ingredient in cosmetic and other pharmaceutical industries.