Determination of Antibacterial Activities of Spirulina Plantensis in Owo Local Government against Selected Pathogens

Spirulina plantensis is a filamentous, spiral-shaped alga used as a primary source of food over the years. They are suspected to have antioxidant and antimicrobial activities. Therefore, this study aimed at determining the antimicrobial activities of Spirulina plantensis extracts in Owo local government, Ondo-State, Nigeria. Spirulina platensiswas sampled from the Enete river and cultivated in the laboratory on synthetic media andriverwater. The biomass was harvested after ten days, and extraction of bioactive compounds was carried out using the maceration method. The ethanols, hot and cold-water extracts of S. plantensis were tested against pathogenic strains of Staphylococcus aureus and Pseudomonas aeruginosa using the agar well and disk diffusion methods. The extracted pigments were identified by thin-layer chromatography. The results showed that the tested microbes were resistant to thebioactive compounds in S. plantensis algal extract. Comparative antibiotic tests against the bacteria strains showed resistance to all antibiotic disks used. The growth pattern of the algae on the synthetic medium was poor as compared to that of river water used as control. There was a deterioration of the algae growth from day three of cultivation on the synthetic medium which could be attributed to nutrient depletion. Thin-layer chromatography revealed bands that confirmedthat biological components were present in the algae which were xanthophylls, chlorophyll b, chlorophyll a, Beta-carotene and phycobiliprotein.