Diversity of culturable bacteria in deep-sea water from the South Atlantic Ocean.

The variability of culturable bacterial diversity and distribution was studied by phylogenetic analysis of 16S rRNA sequences. Seventeen water samples were examined and were collected, from different depths in the range of 5 m to 2700 m at 3 sampling sites (CTD06, CTD10 and CTD11) in the South Atlantic Ocean. Phylogenetic analysis of 16S rRNA gene sequences revealed a significant diversity of culturable bacteria. A total of 247 strains clustered into 8 classes: γ-Proteobacteria, α-Proteobacteria, Actinobacteria, Actinomycetales, Bacilli, Flavobacteria, Opitutae and Sphingobacteria. The 17 water samples were dominated by populations of strains belonging to the genus Erythrobacter (16.60%). Of the 247 strains, 10 were potential new species and might form a minor population in the deep sea. To our knowledge, this is the first report to analyze the diversity of culturable bacteria in the South Atlantic Ocean from different depths across the water column.