Functional genomic analysis of an uncultured δ-proteobacterium in the sponge Cymbastela concentrica

Marine sponges are ancient, sessile, filter-feeding metazoans, which represent a significant component of the benthic communities throughout the world. Sponges harbor a remarkable diversity of bacteria, however, little is known about the functional properties of such bacterial symbionts. In this study, we present the genomic and functional characterization of an uncultured delta-proteobacterium associated with the sponge Cymbastela concentrica. We show that this organism represents a novel phylogenetic clade and propose that it lives in association with a cyanobacterium. We also provide an overview of the predicted functional and ecological properties of this delta-proteobacterium, and discuss its complex interactions with surrounding cells and milieu, including traits of cell attachment, nutrient transport and protein-protein interactions. The ISME Journal (2011) 5, 427-435; doi: 10.1038/ismej.2010.139; published online 2 September 2010