PS 49-151 - A genomic catalog in a stratified tropical estuary in Caribbean coast of Colombia.

Background/Question/Methods

Microbes are represented by several forms of life with less than 200 μm in size and an evolutionary trajectory of ~3,500 million years, with several lineages encompassing most of the existence of the planet. Different microbial habitats have been explored. However, oceanic and coastal areas such as estuarine habitats remain poorly investigated. Even though estuaries are only accounted for 0.3% of the global ocean, these cover areas of high biological productivity when compared to sea and continental waters.An approach to study microbes is based on the analysis of their 16S rRNA gene transcripts by reverse transcription and subsequent sequencing of the resulting complementary DNAs using the Illumina MiSeq sequencing platform. Samples were collected using niskin bottles at the target depths of the project. Subsequently, they were filtered in the laboratory and preserved using ARNlater. We inferred functions from 16S rRNA genes using the iVikodak tool at genus level, which allowed to address specific functions of interest inside prokaryote community and compare differet communities.

Results/Conclusions

We here report, for the first time, a highly diverse microbial community from a tropical estuarine ecosystem in Colombia (7° 55′–8° 40′N and 76° 53′–77° 23′ W), as well as potentially metabolically complex. The studied estuarine habitat was completely stratified with a salinity gradient from fresh to marine waters flowing from south to north of Caribbean Colombia. Among the top ten groups at the order level, Alteromonadales, Betaproteobacteriales, Chloroplast, Flavobacteriales, Oceanospirillales, Rhodobacterales, Rhodospirillales, SAR11 and SAR86 clades, and Synechococcales were detected. This result was accompanied of a potential metabolic gradient that was enriched from the fresh to marine waters.This is the first work of microbes in this tropical estuary and reveals the metabolic diversity of the entire ecosystem, also with relevance in biogeochemical terms.