Isolation and Characterization of Terrestrial Cyanobacterium Producing Commercially Important UV-B Absorbing Compound

Mycosporine-like amino acids (MAAs) constitute an important class of small water-soluble ultraviolet radiation (UV)-absorbing compounds to counteract UV damages in algae and other organisms, and have potential applications in sun care products as the active ingredients. In this study, one filamentous cyanobacterium strain was isolated from the soil in southeast of Niger (Diffa), which received strong UV radiation in summer. The 16S rDNA phylogenetic analysis classified the new isolate as Leptolyngbyasp.CN1. MAA production was low in Leptolyngbya sp.CN1 under white light condition but was significantly enhanced by prolonged UV-B treatments. Liquid chromatography revealed one dominant type of MAAs in Leptolyngbya sp.CN1, and this kind of MAA was characterized as shinorine based on special characteristics of in line absorption spectrum and mass spectrum. The shinorine content was as high as 940 ug.mg-1 dry weight after 4 days of UV-B treatment. The present investigation indicates considerable shinorine is induced to protect Leptolyngbya sp.CN1 from UV-B radiation, and also provide an avenue to explore the source of various MAAs from the biotechnology perspective.