Bioactive potential of biomass and lipids of halophilic cyanobacterium and microalgae

Halophilic microalgae and cyanobacteria are gaining attention in human nutrition for their bioactive compounds. This study evaluates the nutritional value of biomass and lipids of two halophilic microalgae, Halamphora sp. and Dunaliella salina, and the cyanobacterium Phormidium versicolor, cultured under laboratory conditions. P. versicolor had the highest lipid (19.64 ± 0.56% DW) and carbohydrate (33.93 ± 0.46% DW) contents. Halamphora sp., with a rich mineral profile, accumulated triacylglycerols, phospholipids (25% DW), galactolipids (7% DW), and a high concentration of eicosapentaenoic acid (9.17 ± 0.40 mg/g lipids). D. salina was a rich source of carotenoids, particularly lutein (1.03 ± 0.04 mg/g DW), and polyunsaturated fatty acids (PUFAs), which were dominated by C18:3 ω3 (65.77% of total PUFAs). D. salina exhibited the best health-related indices (AI = 0.73, TI = 0.40, H/H = 1.40) due to the highest lutein/zeaxanthin (4.31), ω3/ω6 (2.09), and PUFAs/SFAs (0.95) ratios. Lipophilic pigments, including lutein, zeaxanthin, astaxanthin, and violaxanthin, along with fatty acids, may explain its strong antioxidant activity. The low fiber content (< 6% DW) in the three species suggests that their biomass is highly digestible. Dunaliella and P. versicolor could represent promising nutritional supplements for aquaculture applications, while the relatively high proportion of SFAs in Halamphora sp. suggests a potential for biodiesel applications, which requires further investigation.