The antimicrobial efficiency of some green seaweeds from the Mediterranean coast against some pathogenic bacteria

During the past several years, microbial resistance to common antibiotics has continually increased, and this growing resistance threatens the effective treatment of bacterial infections. Thus, there is increased research on novel drugs like seaweeds. In this study, crude extracts of three seaweeds (Ulva clathrate, Ulva lactuca and Ulva compressa) were obtained with a Soxhlet extraction apparatus. Evaluation of antimicrobial efficiency was carried out using well diffusion method and microdilution method (MIC) at different concentrations (100-0.195mg/ml) for Staphylococcus aureus and Escherichia coli. The green seaweed extracts produced inhibition zones ranging from 7 to 12.5 mm. Methanol extracts produced the strongest inhibitory activity against the tested bacterial species. Overall, this study provides data on the potential use of algal extracts for the development of antimicrobial agents to treat infectious diseases.