Amino acid and fatty acid profiles of four species of macroalgae from Aqaba and their suitability for use in fish diets

Samples of the four species of algae, Ulva lactuca L. (Chlorophyta), Enteromorpha compressa L. Greville (Chlorophyta), Padina pavonica L. Thivy (Phaeophyta) and Laurencia obtusa (Hudson) Lamouroux (Rhodophyta) were collected from Aqaba during February, April and early June of 1995. The biochemical composition (total protein, amino acids, lipid and fatty acids) of the four species was determined. Protein content (% dry weight) ranged from 13.6% in E. compressa to 24.5% in L. obtusa. The lipid content (% dry weight), by contrast, ranged from 4.6% in E. compressa to 6.2% in L. obtusa. All essential amino acids except methionine and cystine in L. obtusa, proline in P. pavonica, proline and cystine in U. lactuca were present in relatively high levels. Polyunsaturated fatty acids represented 50.1 to 66.3% of the total fatty acids, whereas saturated fatty acids accounted for 15.0-30.1% of the total fatty acids. Judging from their amino acid and fatty acid composition, the four species of algae appear to be potential sources of dietary protein and lipid for fish. (C) 1997 Elsevier Science B.V.