Microbial Functioning and Community Structure Variability in the Mesopelagic and Epipelagic Waters of the Subtropical Northeast Atlantic Ocean

Author(s)
Federico Baltar, Javier Aristegui, Josep M. Gasol, Gerhard Herndl
Abstract

We analyzed the regional distribution of bulk heterotrophic prokaryotic activity (leucine incorporation) and selected single-cell parameters (cell viability and nucleic acid content) as parameters for microbial functioning, as well as bacterial and archaeal community structure in the epipelagic (0 to 200 m) and mesopelagic (200 to 1,000 m) subtropical Northeast Atlantic Ocean. We selectively sampled three contrasting regions covering a wide range of surface productivity and oceanographic properties within the same basin: (i) the eddy field south of the Canary Islands, (ii) the open-ocean NE Atlantic Subtropical Gyre, and (iii) the up-welling filament off Cape Blanc. In the epipelagic waters, a high regional variation in hydrographic parameters and bacterial community structure was detected, accompanied, however, by a low variability in microbial functioning. In contrast, mesopelagic microbial functioning was highly variable between the studied regions despite the homogeneous abiotic conditions found therein. More microbial functioning parameters indicated differences among the three regions within the mesopelagic (i.e., viability of cells, nucleic acid content, cell-specific heterotrophic activity, nanoflagellate abundance, prokaryote-to-nanoflagellate abundance ratio) than within the epipelagic (i.e., bulk activity, nucleic acid content, and nanoflagellate abundance) waters. Our results show that the mesopelagic realm in the Northeast Atlantic is, in terms of microbial activity, more heterogeneous than its epipelagic counterpart, probably linked to mesoscale hydrographical variations.

Organisation(s)
External organisation(s)
Universidad de Las Palmas de Gran Canaria, Spanish National Research Council (CSIC)
Journal
Applied and Environmental Microbiology
Volume
78
Pages
3309-3316
No. of pages
8
ISSN
0099-2240
DOI
https://doi.org/10.1128/AEM.07962-11
Publication date
2012
Peer reviewed
Yes
Austrian Fields of Science 2012
106022 Microbiology, 106047 Animal ecology
Portal url
https://ucris.univie.ac.at/portal/en/publications/microbial-functioning-and-community-structure-variability-in-the-mesopelagic-and-epipelagic-waters-of-the-subtropical-northeast-atlantic-ocean(3d30174a-4e52-4d5d-a35d-03d6caceb86f).html