Two marine sponges-associated cultivable bacteria: Diversity and biological activities

Marine sponges harbor diverse bacterial communities. Sponge associated bacteria produce potential secondary metabolites of medical use. Little is known about sponge associated diversity from red sea therefore, we have collected two sponge samples i.e., Pione vastifica and Siphonochalinna siphonella collected from north of red sea in Obhur region, Jeddah Saudi Arabia. By using culture dependent method, we have isolated 95 different bacterial species from two marine sponge samples. These marine bacteria were screened for their antagonistic potential against fungal pathogens (Phytophthora capsici and Pythium ultimum) and human pathogenic bacteria (E. coli, Methicillin-resistant Staphylococcus aureus, E. faecalis, and P. aeroginosa). Among all 37 (39%) marine bacteria showed inhibition against oomycetes, only 27 (28.4%) exhibited antibacterial activity while 19 (20%) exhibited both antifungal and antibacterial activities. These bacterial strains were further screened for enzyme production (cellulase, protease, lipase, and amylase). Most of the strains were positive for production of lipase enzyme. These antimicrobial activities and enzyme production suggest their role in marine sponge as protecting against different marine pathogens. Taxonomic and phylogenetic analyses on the basis of 16S rRNA gene sequences showed that dominant phylum was gamma-Proteobacteria. Our results highlighted that marine sponges are potential source of marine bacteria producing antimicrobial metabolites and enzymes of pharmaceutical and industrial significance.