Isolation and Molecular Identification of Oil Degrading Bacteria associated with Pachychalina sp sponge

The aim of this study was to isolate and molecular identification of associated bacteria in sponges, with potential ability of biodegrading crude oil. Serial dilutions of homogenized Pachychalina sp. mesohyl were cultured in suitable medium for growth of marine microorganism. Obtained colonies were screened based on emulsification index and growth in medium containing 2% oil. Six strains which showed the highest growth rate and emulsification index were tested for the amount of oil removal in the minimal salt medium. Also the molecular identification was done Based on the 16SrRNA sequence and PCR. Removal of oil based on two methods; dry weight and absorption at 420 nm confirmed each other and both followed the same pattern. Accordingly KE5 and KE8 strains showed the highest degree of oil removing and molecular identification results revealed that they were most similar to strains of Staphylococcus aureus subsp. N31 and Luteimonas terricola BZ92r respectively. Also according to the results of bioinformatics analysis, it seems KE6 and KE7 respectively with 84% and 90% similarity with Exiguobacterium sp. AT1b and Pseudomonas rhodesiae CIP 104664 strains, have considerable potential for further molecular and biochemical studies .