Diverse bacterial microbiome from the common shallow water Caribbean and Western Atlantic sponge Cinachyrella

Marine sponges are vital components of benthic and coral reefs ecosystems , providing shelter and nutrition for many organisms. Because sponges can filter large quantities of seawater, they constitute an essential link between the pelagic and benthic environment. Many sponge species harbor high diversity and abundance of microbes (Archaea, Bacteria and eukaryotes) which can constitute up to 40% of the total sponge biomass. Bacteria abundance in sponge tissues can be two- to four- fold higher than concentration in the surrounding seawater. Furthermore, some bacteria permanently inhabit the sponge tissues while others are rapidly consumed. Here, we explore the bacterial and archaeal community diversity of the sponge Cinachyrella sp. using 16S rDNA tag pyrosequencing. Cinachyrella sp. are common shallow water Caribbean and Western Atlantic sponges that inhabit the reefs of south Florida and we collected specimens and seawater from the same reef at different times for one year. Over 14,000 rRNA amplicon sequences were analyzed from the sponges and 3,000 from the seawater. A total of 675 OTUs (> or= 97 % identity; 12 OTUs for archaea and 663 OTUs for bacteria) were detected in the sponge samples. OTUs belonged to 21 bacterial and 2 archaeal phyla and candidate phyla. Interestingly, our sponge samples appear to form two distinct groups, Group 2 with high Bacterial diversity (21 phyla) and Group 1 with lower diversity (12 phyla) and a diversity closer to the bacterial diversity of the seawater). These two sponge groups were observed independently of the time of year of sample collection. Both groups were dominated by Proteobacteria, but Group 1 had more Alphaproteobacteria and Group 2 had more Gammaproteobacteria. Abundant phyla also abundant in Group 1 included Actinobacteria, Bacteroidetes and Cyanobacteria. Group 2 had a few phyla that were present at very low abundance or absent in Group 1: Acidobacteria, Chloroflexi, Nitrospirae, PAUC34f, Poribacteria and Verrucomicrobia. Together with its ecology and concurrent transcriptome analysis of Cinachyrella sp in our laboratory, the microbial data can help establish the sponge as a useful experimental model.