After a series of dilutions, 100µl of diluents was spread on Zobell marine agar medium plates (peptone 5g, yeast extract 1g, ferrous phosphate 0.01g, agar 15g, distilled water
250 ml, aged sea water 750 ml, pH 7.2).The plates were incubated at 25oC for one week and bacterial colonies showing different morphological characteristics were transferred onto fresh Zobell agar medium plates (Indraneel et al., 1999).