Determination of antifungal activity of Staphylococcus haemolyticus and Bacillus sp. Isolated from native sponge of Persian Gulf

The presence of a large number of microorganisms has been proven in many species of sponges. The purpose of this study was to determine the antifungal properties of sponge associated bacteria, which so far has not been reported in Iran. For this aim, the mesohyle tissue of Haliclonia simulanse sponge obtained from coastal waters of Bushehr Province was inoculated with appropriate dilutions in culture media. At primary screening, eight strains were obtained. To determine the antifungal properties of isolated bacteria, two methods consist of diffusion of disk and disk agar against 3 strains of fungi Rhizoctonia solani, Penicillium italicum and Fusarium oxysporum were used. In order to determine the compounds in methanol extract of strain number 4 GC-MS was performed. The molecular identification of strains 4 and 7, which had the highest antifungal properties, indicated that strain 4 had the most similarity of 98% with Bacillus sp. (With a genetic distance of 0/004) and strain 7 has the highest similarity of 95% with Staphylococcus haemolyticus (with a genetic distance of 0.02). Strains 4 and 7 were registered at NCBI with access numbers KY31376 and KY71394, respectively. In disk agar method, the highest antifungal effect belongs to Bacillus sp.  that produced a no-growth field with a diameter of 28.38 mm against R.solani. Staphylococcus haemolyticus showed the highest antifungal effect against F. oxysporum with the creation of an inhibition zone with a diameter of 27.41 mm. In the disc diffusion method, methanol extracts of Bacillus sp and Staphylococcus haemolyticus had the most anti-fungal effects.