Divergent Microbiota Dynamics along the Coastal Marine Ecosystem of Puerto Rico.

Understanding the different factors shaping the spatial and temporal distribution of marine microorganisms is fundamental in predicting their responses to future environmental disturbances. There has been, however, little effort to characterize the microbial diversity including the microbiome dynamics among regions in the Caribbean Sea. Toward this end, this study was designed to gain some critical insights into microbial diversity within the coastal marine ecosystem off the coast of Puerto Rico. Using Illumina MiSeq, the V4 region of the 16S rRNA gene was sequenced with the goal of characterizing the microbial diversity representative of different coastal sites around the island of Puerto Rico. This study provided valuable insights in terms of the local bacterial taxonomic abundance, α and β diversity, and the environmental factors shaping microbial community composition and structure. The most dominant phyla across all 11 sampling sites were the Proteobacteria, Bacteroidetes, and Planctomycetes, while the least dominant taxonomic groups were the NKB19, Tenericutes, OP3, Lentisphaerae, and SAR406. The geographical area (Caribbean and Atlantic seas) and salinity gradients were the main drivers shaping the marine microbial community around the island. Despite stable physical and chemical features of the different sites, a highly dynamic microbiome was observed. This highlights Caribbean waters as one of the richest marine sources for a microbial biodiversity hotspot. The data presented here provide a basis for further temporal evaluations aiming at deciphering microbial taxonomic diversity around the island, while determining how microbes adapt to changes in the climate.