Light irradiance modifies the fatty acid composition of Amphidinium carterae (Dinophyceae)

ABSTRACTAmphidinium carterae is a dinoflagellate of increasing interest for producing bioactive compounds. The aim of this study was to investigate the effect of five irradiances (50, 100, 150, 200 and 250 µmol photon m–2 s–1) on the fatty acid profile of A. carterae. The results show that high irradiances increase the lipid productivity (36.65 mg l–1 d–1 at 50 µmol photon m–2 s–1 to 90 mg l–1 d–1 at 250 µmol photon m–2 s–1). High irradiance increased the content of polyunsaturated fatty acids (PUFAs) relative to the total content of fatty acids (40.0% at 50 µmol photon m–2 s–1 to 53.23% at 250 µmol photon m–2 s–1) and decreased the amount of monounsaturated fatty acids (MUFAs) (14.30% at 50 µmol photon m–2 s–1 to 6.04% at 250 µmol photon m–2 s–1). The higher PUFAs content was due to docosahexaenoic acid (DHA; 20.76% at 50 µmol photon m–2 s–1 to 30.63% at 250 µmol photon m–2 s–1) and eicosapentaenoic acid (EPA; 14.91% at 50 µmol photon m–2 s–1 to 18.96% at 250 µmol photon m–2 s–1). Palmitic acid (C16:0) had the highest content among saturated fatty acids (19.87% at 50 µmol photon m–2 s–1 to 22.29% at 250 µmol photon m–2 s–1). The proportion of neutral lipids tended to increase under high irradiances (100–250 µmol photon m–2 s–1). At the lowest irradiance (50 µmol photon m–2 s–1), the proportion of polar lipids was higher than that of neutral lipids. PUFAs had the main content within polar lipids at the five irradiances (47%–50%). The major neutral lipids were SFAs at the five irradiances (47%–51%). It was concluded that the irradiance levels influence the lipid metabolism of A. carterae. The increase in irradiance level raises the production of lipids and the content of EPA and DHA for potential utilization in the biotechnological, aquaculture and nutraceutical industries.KEYWORDS: DinoflagellatesDocosahexaenoic acidLipid classesPolyunsaturated fatty acids AUTHOR CONTRIBUTIONSA.M.F.: design and implementation of the experiments and manuscript preparation.M.P.S.S. supervision of experiments and data processing, contribution to manuscript preparation, and financial support.STATEMENT OF INFORMED CONSENT, HUMAN/ANIMAL RIGHTSNo conflicts, informed consent, or human or animal rights are applicable to this study.ACKNOWLEDGEMENTSThis work has been funded by Consejo Nacional de Ciencia y Tecnología (CONACyT) (Grant Project: SEP-CONACyT 130074), and CICESE (Grant Project: 623108). A.M.F. thanks the postdoctoral scholarship from the Oceanography Division of CICESE and the postdoctoral scholarship from CONACyT.DISCLOSURE STATEMENTNo potential conflict of interest was reported by the authors.Additional informationFundingThis work was supported by the Centro de Investigación Científica y de Educación Superior de Ensenada, Baja California [623108].