Antimicrobial activity of bacteria from marine sponge and bioactive metabolites of sp. EA348.

Discovery of potential bioactive metabolites from sponge-associated bacteria have gained attraction in recent years. The current study explores the potential of sponge () associated bacteria against bacterial and fungal pathogens. Sponge samples were collected from Red sea in Obhur region, Jeddah, Saudi Arabia. Of 29 isolated bacteria belong to four different classes i.e. (62%), (21%), α- (10%) and (7%). Among them nineteen (65%) bacterial strains showed antagonistic activity against oomycetes and only 3 (10%) bacterial strains were active against human pathogenic bacteria tested. Most bioactive genera include (55%), (13%) and (10%). Enzyme production (protease, lipase, amylase, cellualse) was identified in 12 (41%) bacterial strains where potential strains belonging to and groups. Production of antimicrobial metabolites and hydrolysates in these bacteria suggest their potential role in sponge against pathogens. Further bioactive metabolites from selected strain of sp. EA348 were identified using LC-MS and GC-MS analyses. We identified many active metabolites including antibiotics such as Amifloxacin and fosfomycin. Plant growth hormones including Indoleacetic acid and Gibberellin A3 and volatile organic compound such as methyl jasmonate were also detected in this strain. Our results highlighted the importance of marine bacteria inhabiting sponges as potential source of antimicrobial compounds and plant growth hormones of pharmaceutical and agricultural significance.