The prokaryotic microbiome of the red calcified macroalgae Corallina officinalis has been sequenced using the V6 region of 16S rRNA. Raw sequence reads. Corallina officinalis microbiome

The living prokaryotic microbiome of the calcified geniculate (articulated) red alga, Corallina officinalis from the intertidal seashore is characterised for the first time basedon the V6 hypervariable region of 16S rRNA. Results revealed an extraordinary diversity of bacteria associated with the microbiome. Thirty-five prokaryotic phyla wererecovered, of which Proteobacteria, Cyanobacteria, Bacteroidetes, Actinobacteria, Planctomycetes, Acidobacteria, Verrucomicrobia, Firmicutes and Chloroflexi made up thecore microbiome. Unclassified sequences made up twenty-five percent of sequences suggesting insufficient sampling of the world’s oceans/macroalgae. The greatest diversityin the microbiome was on the upper shore, followed by the lower shore then the middle shore, although the microbiome community composition did not vary between shorelevels. The C. officinalis core microbiome was broadly similar in composition to those reported in the literature for crustose coralline algae (CCAs) and free-living rhodoliths.Differences in relative abundance of the phyla between the different types of calcified macroalgal species may relate to the intertidal versus subtidal habit of the taxa andfunctionality of the microbiome components. The results indicate that much work is needed to identify prokaryotic taxa, and to determine the nature of the relationship ofthe bacteria with the calcified host spatially, temporally and functionally.