ماندانا زارعی

Introduction: The aim of this project was Isolation of biosolfactant from the sponge associated marine microorganisms and its application in MEOR.Methods: Marine sponge Haliclonia simulans was collected from coast water of Kharko Island in Persian Gulf. The internal mesohyl was homogenized and the aliquot was placed on various isolation media. A spong-associatted marine bacteria Staphylococcus hominis DM122 was screened and evaluated for the production of biosurfactant. Biosurfactant production was confirmed by conventional screening methods including hemolytic activity, lipase production and microbial adhesion to the hydrocarbon. In the next step, Characterization of biosurfactant determined by Emulsification activity, Oil displacement test, Drop collapsing test, Solubilization of Crystalline Anthracene, CTAB agar. Biochemical and molecular Identification was performed. Identification of biosurfactant producer was confirmed with phylogenetic analysis. After extracting genomic DNA, Universal 16srDNA primer was used for the amplification of gene. Time course of biosurfactant production was Determined. Stability of biosurfactants performed at different temperatures, pH and NaCl and the emulsification index was calculated.Results: Maximum growth and maximum amount of biosurfactant was obtained 96 h and 120 h after inoculation. Biosurfactant obtained from Staphylococcus hominis DM122 showed an excellent resistance at NaCl 10%, pH 2-10 and temperature 20-1000C. Emulsification index was 18.75, oil displacement test 77.7 mm and Solubilization of Crystalline Anthracene was obtained 1.7.Conclusion: This investigation suggests that biosurfactants of Staphylococcus hominis DM122 is appropriate candidates for MEOR.