Fatty acid profile, nutritional potential and biological activity of green macroalgae from the Northern Tunisian coast

Introduction Marine macroalgae possess very complex and diverse lipid composition. Fatty acids from marine macroalgae are a sustainable and valuable source of essential nutrients with significant health benefits, including cardiovascular protection, neuroprotection, anti-inflammatory properties, and wide applications in the nutraceutical and pharmacological industries. Methods To evaluate the fatty acids composition of macroalgae, from Ulvophyceae class, collected from northern Tunisian coast Cap Zebib (CZ), Rafraf (R) Ghar el Melh lagoon (G), Carthage bay (C), La Marsa (M), Tunis North Lake (L), ten species were studied ( Bryopsis muscosa ( R ) , Caulerpa prolifera (L), Caulerpa racemosa (R), Cladophora laetivirens (CZ, R), Codium fragile (M), Codium tomentosum (R), Dasycladus vermicularis (CZ), Halimeda tuna (M), Ulva rigida (G) and Ulva linza (C). Fatty acid contents and specific profiles were determined by gas-chromatography. To assess the nutritional quality and potential health benefits of the studied macroalgae, the unsaturation index atherogenic and thrombogenic index ((U.I.), AI and TI)) were calculated. Additionally, the antimicrobial and cytotoxic activities of crude organic algal extracts against pathogenic bacteria and two microalgal species were evaluated. Results As results, total fatty acid contents, expressed per percentage of dry weight, ranged from 0.04% to 0.70%. Generally, saturated fatty acids (SFA) were major components percentage of total FA content 75.02%, with palmitic acid (C16:0) being the most abundant and Codium tomentosum containing the highest amount. D. vermicularis showed the better profile in terms of FA composition with a low AI (1.75) and a very low TI (0.4), making it an excellent source of healthy lipids. Ulva linza and Bryopsis muscosa exhibited the most important spectrum of antibacterial activity, inhibiting the growth of multiple strains as P. aeruginosa and E. faecalis . Conclusion This study provides a comprehensive overview of the lipid profiles of some green macroalgae and their potential applications in food and drug industries, with a particular emphasis on their health implications and antimicrobial properties.