Antibacterial activity of actinomycetes isolated from native sponge of Persian Gulf (Kharku Island) against pathogens

Resistant of pathogens to common antibiotics is a major global problem, and efforts discover new antibiotics from less known resources, is an inevitable. Native sponges of Persian Gulf have high potential in the field of medical biology, but have received little attention. In this study, actinomycetes that capable to produce anti-bacterial metabolites isolated and examined. Two sponges of Persian Gulf Haliclona simulans and Dictyonella sp. were collected with scuba diving in the waters around the Kharku Island and mesohyle of sponges were used to obtained actinomycetes. A Primary screening was carried out to identify antibiotic producing strains by cross streak method. Chloroform and methanol extracts obtained from active strains and their impacts against pathogens were examined by disk diffusion method. Moreover, the most active actinomycete was identified by molecular method. Among 12 actinomycetes obtained in primary screening, 7 isolates had the ability to inhibit growth of pathogenic microorganisms and mz7 had the most and mz3 and mz5 had the least  inhibition activities. In the disk diffusion test, methanol extract of mz1 and chloroform extract of mz7 displayed the highest anti-bacterial activity. Molecular method showed that isolated mz7 had 97% similarity to Micrococcus yannanensis strain YIM 65004. According to significant anti-bacterial properties of identified strains in this study, it seems that there is potential to do further investigation in this context.