Résumé:
Our main objective is the study of the characterization of some biochemical elements and also of the metallic contamination by three trace metals namely Zinc, Copper and Lead, at the level of the green alga Ulva lactuca sp. the Sidi El Adjel beach on the Algerian west coast. The results indicate a high yield of crude extract 7.9% for methanol and 2% for petroleum ether Moreover, the green alga Ulva lactuca sp is characterized by a high content of total polyphenols 0.383 mg EAG / g MS. The study of the antioxidant power by two methods, the trapping of the radical DPPH, and the quantification of the total antioxidant capacity, reveals the presence of antioxidant properties for the studied extract. The evaluation of the sample shows that the green alga studied is low in lipids whose content is evaluated at (5.5%). Biochemical analysis indicates that algae have the advantage of being rich in protein and raw ash with contents of about (30.6%) and (22%) respectively. With regard to metallic contamination, our green alga has higher levels of zinc followed by copper and then lead, however these rates remain relatively questionable given the short period of our sampling. All these results obtained in vitro are only a first step in the search for biologically active natural substances from marine algae. Further long-term studies should be considered to confirm the bio-activity of seaweeds as well as their bioaccumulation capacity.
