Steve W. Ross Sandra D. Brooke Christina A. Kellogg 2016 <p><span>Compared to tropical corals, much less is known about deep-sea coral biology and ecology. Although the microbial communities of some deep-sea corals have been described, this is the first study to characterize the bacterial community associated with the deep-sea octocoral, </span><i>Paramuricea placomus</i><span>. Samples from five colonies of </span><i>P. placomus</i><span> were collected from Baltimore Canyon (379–382 m depth) in the Atlantic Ocean off the east coast of the United States of America. DNA was extracted from the coral samples and 16S rRNA gene amplicons were pyrosequenced using V4-V5 primers. Three samples sequenced deeply (&gt;4,000 sequences each) and were further analyzed. The dominant microbial phylum was Proteobacteria, but other major phyla included Firmicutes and Planctomycetes. A conserved community of bacterial taxa held in common across the three </span><i>P. placomus</i><span>colonies was identified, comprising 68–90% of the total bacterial community depending on the coral individual. The bacterial community of </span><i>P. placomus</i><span>does not appear to include the genus </span><i>Endozoicomonas</i><span>, which has been found previously to be the dominant bacterial associate in several temperate and tropical gorgonians. Inferred functionality suggests the possibility of nitrogen cycling by the core bacterial community.</span></p> application/pdf 10.7717/peerj.2529 en PeerJ Bacterial community diversity of the deep-sea octocoral <i>Paramuricea placomus</i> article