Sh. Dashtegol - Department of Hygiene, Science and Research Branch, Islamic Azad University, Tehran
A. Motalebi Moghanchoghi - Department of Hygiene, Science and Research Branch, Islamic Azad University, Tehran
V. Razavilar - Department of Hygiene, Science and Research Branch, Islamic Azad University, Tehran
M.S. Mortazavi - Persian Gulf and Oman Sea Ecological Research Institute,Bandar Abbas, Iran

One of the subjects attracted the interest of researchers in recent years in the field of biology is marine algae, due to their nutritional value, their benefits for health and their biological activities. In this study, steroid fractions of acetone extract of Colpomenia sinuosa (Phaeophyceae alga) from the Persian Gulf and Oman sea (Iran) have studied and evaluated for their antibacterial activity against pathogenic bacteria: one gram-positive bacterium (Staphylococcus aureus) and two gram-negative bacteria (Escherichia coli, Pseudomonas aeroginosa). Antimicrobial susceptibility tests have expressed in terms of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) of the test organisms with respect to the acetone extracts of Colpomenia sinuosa. Extracts of all tested marine algae have showed inhibition against all of the pathogenic microbes. In addition, the highest inhibition activity among all the extracts was shown from Cholestane fraction to S.aoreus and lower inhibition activity was shown from Oleic acid fraction to P. aeruginosa.

Brown algae, Colpomenia sinousa, Persian Gulf, Biological activity, Steroids