| Abstract: | The protein content of the filamentous Cladophora glomerata (L.) Kz., Ulothrix zonata (Web, & Mohr) Kz. and Spirogyra sp., collected from natural populations for 1 year, averaged 8.0–12.4% of the total dry weight; whereas, the corresponding levels of lipid, cellulose and ash were 11.9–16.1%, 10.0–17.8% and 14.6–24.0%, respectively. Mean values for carbohydrates, estimated by difference, ranged from 32.8 to 56.0%. The colonial Scenedesmus dimorphus (Turp.) Kz. and the unicellular Cosmarium laeve Rab., on the other hand, contained more protein, lipid and carbohydrate (estimated by difference) averaging 13–15.0%, 22.5–25.9% and 415–46.8%, respectively, and less cellulose (7.5–9.8%) and ash (8.2–9.8%). A consistent pattern of seasonal variation in the proximate composition was not normally evident for any species, reflecting the influence of several environmental parameters on the algae. Cladophora contained the greatest amount of phospholipid averaging; 10% by weight of total lipid with the smallest quantity (5%) in Scenedesmus. The predominant phospholipid fatty acid in all species was C18:1 followed by C18:2, C18:3 and C16:1 in Cladophora, Ulothrix and Spirogyra, and C16:1, C18:2 and C16:0 in Scenedesmus and Cosmarium. Oleic (C18:1) and hexadecanoic (C16:1) acids were predominant in the neutral lipids of all the algae, followed by C16:0, C18:2 and C18:3. The concentration of the different fatty acids of each Species varied considerably during the year with the proportion of C16:0 and C16:1, usually rising and that of C18:1 failing during the colder months. |
