Interactions between sponges and marine bacteria as a route to the discovery of novel bioactive compounds

Abstract

The bacterial community architecture associated with four species of sponges, Halichondria panicea, Suberites domuncula, S. carnosus and Pachymatisma johnstonia was investigated using culture-dependent and culture-independent strategies. Marine agar was found to be the best of several media used for cultivation of culturable bacteria associated with sponges. Molecular methods, including denaturing gradient gel electrophoresis (DGGE), 16S rDNA cloning and sequence analysis suggested a bacterial community different from that identified using culture-dependent methods. DGGE can provide a profile of the whole community of the sponge and facilitate screening of large-scale samples. 90% of the bacteria associated with these four sponges were sponge species-specific. S. carnosus was also transferred to an aquarium to study kinetic changes of sponge-associated bacterial communities. DGGE analysis showed the consistent presence of some particular bands suggesting the continued presence of species of symbiotic bacteria.