Abstract

Natural molecules of different origins and mainly those from marine algae create a range of natural bioactive principles with strong therapeutic potential. bioactive compounds present in many species of algae have particularly interesting nutritional properties. This study focuses on determining the phytochemical and nutritional compounds as well as the antioxidant, antibacterial and antifungal activity of marine green algae. Ulva rigida harvested on the Algerian coast. The different extracts of the ulva were analyzed and subjected to several physicochemical and biological tests. The results of the various dosages of primary and secondary metabolites revealed that Ulva rigida is rich in water-soluble proteins, total sugars and polyphenols while they are low in amino acids and total lipids. This algae studied is an excellent natural source of antioxidants and has great antibacterial activity, which is not the case for the antifungal activity which was found to be very weak against the yeast strains studied. All these in vitro results are only a first step towards the search for naturally active biological substances from this green algae with the aim of using it in the bioformulation of various food and agro-food products. Further tests are planned to confirm the bio-activity of the algae.

Keywords:Green algae; Bioactive compounds; Ulva rigida; Antioxidant; Antibacterial; Antifungal activity