Antioxidant and antimicrobial activities of Spirulina from the region of Tamanrasset, Algeria

Introduction: Spirulina (Arthrospira platensis) is a cyanobacterium, classified among the Cyanophyceae or "blue -green algae, " which develops rapidly through photosynthesis. This microorganism appeared on Earth 3.5 billion years ago and has been consumed since antiquity due to its richness in proteins (60-70%), vitamins, and trace elements.Methods: A phytochemical screening is conducted to detect potential secondary metabolites, primarily phenolic compounds. Subsequently, a simplified measurement of the major pigments is performed using spectro-photometry, followed by an evaluation of the activities of the different extracts: antimicrobial properties using the agar diffusion method or antibiogram, and antioxidant properties using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay.Results: Acetone and diethyl ether extracts showed the most potent antibacterial activity against gram-positive and gram-negative bacteria. On the other hand, only the acetone extract showed antifungal activity against Fusarium culmorum. The DPPH test demonstrated that the methanolic extract has antioxidant properties com-parable to ascorbic acid.Discussion/Conclusions: The results showed that Spirulina found in Tamanrasset, in the Algerian Sahara, has, in addition to its nutritional values, tremendous pharmacological potential. More in-depth studies should follow this investigation.