Psychrotolerant Coccomyxa subellipsoidea ASYA6 for sustainable UV protection: A novel green source of mycosporine-like amino acids

Abstract

Mycosporine-like amino acids (MAAs) are biomolecules known for their unique ultraviolet (UV) protective properties in nature. Albeit their widespread commercial use is limited due to low biosynthetic yields, complex purification processes, and high production costs. This study, for the first time, assessed the MAA production capacity and UV protection potential of hydroethanolic extracts from the Antarctic psychrotolerant green microalga Coccomyxa subellipsoidea, without subjecting them to additional purification steps beyond those performed using a fraction collector HPLC. Microalgae were exposed to UVA or UVB radiation for various durations alongside high light to enhance MAA synthesis. Following 72 h of increased PAR and UVB exposure, which led to maximum yield, fatty acid methyl esters and MAA analyses were conducted on the same biomass. The UV-driven induction of MAA production was accompanied by an increase of up to 22 % in the saturation of fatty acids. Spectroscopic and chromatographic analyses confirmed the presence of mycosporine-glycine and shinorine in the hydroethanolic extract which had an in vitro sun protection factor equivalent of 7.3. Elevated antioxidant activity and total phenolic content highlight the richness of bioactive compounds in the extract. Moreover, the extracts exhibited significant stability under various light and dark storage conditions with a maximum loss of 30 % over 60 days. In conclusion, the MAAs obtained from C. subellipsoidea through a cost-effective and purification-free approach demonstrate impressive SPF, stability, and antioxidant properties. This indicates their potential to help develop new biobased, stable UV filters for cosmetics, offering a sustainable alternative to synthetic ones.