Diversity of bacteria associated with the Caribbean coral Montastraea franksi

In this study we characterized the prokaryotic microbiota associated with t he reef-building coral Montastraea franksi in a culture-independent manner by sequencing 16S rDNAs. The majority of the bacteria identified by this me thod were novel species and belonged to a wide variety of microbial groups, with cyanobacteria and Lx-proteobacteria being the most abundant. In contr ast, the bacteria cultured from the same M. franksi samples were closely re lated to previously described bacteria and consisted mostly of) gamma -prot eobacteria. These results show that the microbial diversity associated with corals can be greatly underestimated when relying exclusively on culture-b ased methods. Our analyses also showed that one a-proteobacteria species wa s present in all M. franksi samples isolated from five reefs separated by u p to 10 km. This finding is suggestive of a specific microbe-coral associat ion.