Porites-associated bacterial 16S with coral ages

We investigated the effects of coral host age on microbiome bacterial diversity. This was done by determining the age of 91 individual colonies of Porites lutea collected from five locations in Singapore. Coral ages were established by counting seasonal/annual skeletal banding patterns and validated through alizarin dye staining. Bacterial communities associated with aged corals were profiled by targeting the V4 region of the 16S SSU rRNA. Sequencing of amplicons was performed on the Illumina MiSeq platform. Our results indicate there is no single explanation that can be used to describe how bacterial community diversity changes with increasing host age. Some sampled locations show a significant increase in bacterial diversity as host age increases, while other locations show a decrease in bacterial diversity with increasing host age. In addition to the 91 aged corals that had their bacterial communities profiled, we profiled the bacterial communities of a further 69 P. lutea colonies that were not aged. This allowed us to produce the first comprehensive characterisation of P. lutea associated bacterial communities in Singapore. In total, the bacterial communities associated with 160 individual colonies of P. lutea from eight islands were profiled, we found that all samples were dominated by Proteobacteria and Cyanobacteria. Bacterial communities were significantly different between sampling locations, and the sampling site closest to the influence of the Singapore mainland was most distinct.