Comparison of prokaryotic diversity at two offshore oceanic locations reveals a different microbiota in the Mediterranian Sea

Abstract

The bacterial and archaeal assemblages at two offshore sites located in polar (Greenland Sea) and Mediterranean (Ionian Sea) waters and two depths (50 and 2000 or 3000m respectively) have been studied by PCR amplification and sequencing of the last 450bp of the 16S rRNA gene. A total of 1817 sequences, together with alignable 16S rRNA gene fragments from the Sargasso Sea metagenome database, were analysed to ascertain variations associated to the geographic location and depth. The Ionian 50m sample appeared to be the most diverse and also had remarkable differences in terms of the prokaryotic groups retrieved. Contrastingly, many similarities were found at the level of large-scale diversity between the surface Sargasso database and the Greenland 50m sample. Most sequences with more than 97% similarity, 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 samples had overall similarities, there were important differences that could be due to the warmer deep waters of the Mediterranean Sea.

Citation

Zaballos M., Lopéz-Lopéz A., Ovreas L., Bartual S. G., D'Auria G., Legault B., Alba J. C., Pushker R., Daee F. L. and Rodríguez-Valera F. (2006) Comparison of prokaryotic diversity at two offshore oceanic locations reveals a different microbiota in the Mediterranean Sea. FEMS Microbiology Ecology, 56(3):389-405.