Increased shinorine production through the introduction of mycosporine-like amino acids biosynthetic genes from Pyropia yezoensis and Nostoc punctiforme into Nannochloropsis gaditana

Abstract

The escalating threat of ultraviolet radiation (UVR) necessitates the development of sustainable strategies for protection from UVR exposure. Mycosporine-like amino acids (MAAs) provide natural photoprotection by absorbing and dissipating harmful UVR. Here, we present the engineering of Nannochloropsis gaditana, a marine microalga, for enhanced production of MAAs, specifically shinorine. A novel strain of N. gaditana isolated from Seonjaedo Island, Korea, served as a heterologous host for MAA production. By introducing MAA biosynthetic genes from Pyropia yezoensis and Nostoc punctiforme into the N. gaditana host strain, we generated two transgenic N. gaditana strains capable of overproducing shinorine. The transgenic N. gaditana strains exhibited enhanced resistance to UVR-induced damage, as evidenced by greater photosystem II efficiency and lower reactive oxygen species generation upon exposure to UVR compared with the unmodified host strain. We also discuss the substrate specificity of key enzymes involved in MAA biosynthesis in the transgenic N. gaditana strains. Our study underscores the feasibility of utilizing microalgae for sustainable MAA production and provides insights into the optimization of MAA biosynthesis pathways for commercialization and environmental sustainability.