Characterization of UV-absorbing Mycosporine-like Amino Acids in Freshwater Cyanobacterium Nostoc calcicola
Mamadou Chetima Maina Boukar *
Université de Diffa, Faculté des Sciences de l’Environnement, BP: 78 Diffa, Niger and School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei 430079, China.
Salifou Issa
Université de Diffa, Institut Supérieur en Environnement et Ecologie, BP : 78 Diffa, Niger.
Kaka Kiari Boukar Kellou
Université de Diffa, Faculté des Sciences de l’Environnement, BP: 78 Diffa, Niger.
Moussa Diagara Saley
Université Abdou Moumouni de Niamey, Faculté des Sciences et Techniques, BP : 10662 Niamey, Niger.
Kai Wang
School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei 430079, China.
Mai Moussa Chetima Bagana
Université de Diffa, Institut Supérieur en Environnement et Ecologie, BP : 78 Diffa, Niger.
Grema Moustapha
Université Abdou Moumouni de Niamey, Faculté des Sciences et Techniques, BP : 10662 Niamey, Niger.
Mahamane Ali
Université Abdou Moumouni de Niamey, Faculté des Sciences et Techniques, BP : 10662 Niamey, Niger.
*Author to whom correspondence should be addressed.
Abstract
Mycosporine-like amino acids (MAAs) are gaining attention for their UV photoprotective properties and potential applications in biomedical fields, cosmetics, and toiletries. In this study, Nostoc calcicola a genus of cyanobacteria distributed in freshwater were tested for MAA production. This organism was provided by the Freshwater Algae Culture Collection of the Institute of Hydrobiology, the Chinese Academy of Sciences. It was isolated and cultured in the laboratory, in 500 ml glass flasks containing 300 ml of liquid medium BG11 treated on UV-B light 0.1 Wm–2. At different time, cultures were exposed to UV-B light at intensity 0.1 W. m-1 to determine the Maximum PSII photochemical (Fv/Fm). MAAs were extracted using 100% HPLC grade methanol and separated through high-performance liquid chromatography and liquid chromatography/mass spectrometry. Based on liquid chromatography/mass spectrometry analysis, one MAA compound was identified as porphyra. Thus, UV-B treatment of Nostoc calcicola significantly enhanced the production of UV-absorbing mycosporine-like amino acids (MAAs). The content of porphyra could reach up to 8.5 mg/g dry weight in Nostoc calcicola under UV-B treatments for 2 days. The present cyanobacteria could be used for biotechnology research and the UV-absorbing compound porphyra may be of great value in the development of novel sunscreens.
Keywords: Cyanobacteria, mycosporine-like amino acids, Nostoc calcicola, porphyra, ultraviolet B