Comparative pigment and fatty acid profiling of marine species within the chlorophyte genus Tetraselmis

Microalgae are a sustainable source of nutraceuticals such as omega-3 fatty acids and carotenoid pigments. Therefore, nutraceutical profiling of microalgae is essential to identify high-yielding candidates for cultivation upscaling and commercialisation. The present study investigated the pigment and fatty acid profiles of 10 marine species within the chlorophyte genus Tetraselmis, with a quantitative focus on the high-value nutraceuticals lutein, β-carotene and the omega-3 fatty acid eicosapentaenoic acid (EPA, C20:5 ω3). To achieve this, fatty acid and pigment analyses were carried out via GC-MS and HPLC, respectively. When comparing the 10 Tetraselmis species, identical fatty acid and pigment compositions were observed. Palmitic acid (C16:0), α-linolenic acid (C18:3 ω3) and oleic acid (C18:1) were the primary constituents of the fatty acid profile for the Tetraselmis species. Furthermore, the pigment profile observed for each Tetraselmis species was typical of Chlorophyceae algae and included common green algal carotenoids such as lutein, violaxanthin and neoxanthin. Significant variations in the yields of high-value nutraceuticals were observed. For example, T. suecica (CCAP 66/38) returned the highest yield of EPA (3.10 ± 0.20 mg EPA g⁻¹dw). Moreover, T. suecica (CCAP 66/38) was one of the more prominent Tetraselmis species in relation to β-carotene (7.17 mg β-Car g⁻¹dw) and lutein (0.39 mg lut g⁻¹dw) content. Thus, the present intragenus study documents species-specific responses to common growth conditions and variations in nutraceutical biosynthesis potential. Of note, T. suecica (CCAP 66/38), subject to further cultivation optimisation strategies, may represent a promising commercial source of the bioactive xanthophyll lutein, the provitamin A carotenoid β-carotene and the omega-3 fatty acid EPA.