Comparison of prokaryotic diversity at offshore oceanic locations reveals a different microbiota in the Mediterranean Sea.
The bacterial and archaeal assemblages at two offshore sites located in polar (Greenland Sea; depth: 50 and 2000 m) and Mediterranean (Ionian Sea; depth 50 and 3000 m) waters were studied by PCR amplification and sequencing of the last 450-500 bp of the 16S rRNA gene. A total of 1621 sequences, together with alignable 16S rRNA gene fragments from the Sargasso Sea metagenome database, were analysed to ascertain variations associated with geographical location and depth. The Ionian 50 m sample appeared to be the most diverse and also had remarkable differences in terms of the prokaryotic groups retrieved; surprisingly, however, many similarities were found at the level of large-scale diversity between the Sargasso database fragments and the Greenland 50 m sample. Most sequences with more than 97% sequence similarity, a value often taken as indicative of species delimitation, were only found at a single location/depth; nevertheless, a few examples of cosmopolitan sequences were found in all samples. Depth was also an important factor and, although both deep-water samples had overall similarities, there were important differences that could be due to the warmer waters at depth of the Mediterranean Sea.
Zaballos
Milagros
M
División de Microbiología and Evolutionary Genomics Group, Universidad Miguel Hernández, San Juan de Alicante, Spain.
López-López
Arantxa
A
Ovreas
Lise
L
Bartual
Sergio Galán
SG
D'Auria
Giuseppe
G
Alba
Jose Carlos
JC
Legault
Boris
B
Pushker
Ravindra
R
Daae
Frida Lise
FL
Rodríguez-Valera
Francisco
F
D001105:Archaea / Q000145:classification* / Q000235:genetics; D001439:Bacteroides / Q000145:classification / Q000235:genetics; D045848:Fibrobacter / Q000145:classification / Q000235:genetics; D020459:Genes, rRNA / Q000235:genetics; D006116:Greenland; D008522:Mediterranean Sea; D020560:Proteobacteria / Q000145:classification* / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D012623:Seawater / Q000382:microbiology*; D017423:Sequence Analysis, RNA
D012336:RNA, Ribosomal, 16S