fa Biotechnology Biotechnology پژوهشي Orginal research papers <p>Sponges are the simplest multicellular animals that lack defense mechanisms and rely on chemical defense &nbsp;that have been used by mankind to develop antimicrobial drugs against diseases.&nbsp; The present study was designed to demonstrate the antibacterial and antifungal activities of marine sponge <em>Dysidea pallescens</em> semipolar and nonpolar extracts. In this <a name="OLE_LINK26"></a><a name="OLE_LINK25">study,</a><em> D. pallescens </em>were collected from Hengam Island in the Persian Gulf. The extracts were produced by Bligh and Dyer method. Broth Dilution Methods were used to check the antimicrobial activity of <em>D. pallescens</em> extracts against <em>Escherichia coli</em> (ATCC 15224), <em>Pseudomonas aeruginosa </em>(ATCC 25619), <em>Staphylococcus aureus aureus</em> (ATCC 1764), <em>Bacillus subtilis pizizenii</em> (ATCC 6633), <em>Candida albicans</em> (ATCC10231) and <em>Aspergillus fumigates</em> (PTCC5009). The results showed diethyl ether extract has bactericidal activity against <em>S. aureus aureus </em>(MBC=10mg/mL) and <em>B. subtilis spizizenii</em> (MBC=20mg/mL). <em>D. pallescens</em> diethyl ether extract showed a very weak antifungal activity but methanol extract showed fungicidal activity against <em>A. fumigates </em>(MFC=5mg/mL) and <em>C. albicans</em> (MFC=1.5 mg/mL). Therefore nonpolar-semipolar secondary metabolites of <em>D. pallescens</em> solutions in diethyl ether have shown significant antibacterial activity and polar- secondary metabolites solutions in methanol have shown significant antifungal activity.&nbsp;</p> Antibacterial, Antifungal, Marine sponge, Persian Gulf 200 209 http://jifro.ir/browse.php?a_code=A-10-600-64&slc_lang=fa&sid=1 M. Nazemi melikanazemi@yahoo.com 100319475328460020049 100319475328460020049 Yes Y. Moradi 100319475328460020050 100319475328460020050 No F. Rezvani Gilkolai 100319475328460020051 100319475328460020051 No M.A. Ahmaditaba 100319475328460020052 100319475328460020052 No M. Gozari 100319475328460020053 100319475328460020053 No Z. Salari 100319475328460020054 100319475328460020054 No