 |
| Titel |
Bacterial assemblages of the eastern Atlantic Ocean reveal both vertical and latitudinal biogeographic signatures |
| VerfasserIn |
C. J. Friedline, R. B. Franklin, S. L. McCallister, M. C. Rivera |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 6 ; Nr. 9, no. 6 (2012-06-18), S.2177-2193 |
| Datensatznummer |
250007125
|
| Publikation (Nr.) |
 copernicus.org/bg-9-2177-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| Microbial communities are recognized as major drivers of the biogeochemical
processes in the oceans. However, the genetic diversity and composition of
those communities is poorly understood. The aim of this study is to
investigate the composition of bacterial assemblages in three different water
layer habitats: surface (2–20 m), deep chlorophyll maximum (DCM;
28–90 m), and deep (100–4600 m) at nine stations along the eastern
Atlantic Ocean from 42.8° N to 23.7° S. The sampling of three
discrete, predefined habitat types from different depths, Longhurstian
provinces, and geographical locations allowed us to investigate whether
marine bacterial assemblages show spatial variation and to determine if the
observed spatial variation is influenced by current environmental conditions,
historical/geographical contingencies, or both. The PCR amplicons of the V6
region of the 16S rRNA from 16 microbial assemblages were pyrosequenced,
generating a total of 352 029 sequences; after quality filtering and
processing, 257 260 sequences were clustered into 2871 normalized
operational taxonomic units (OTU) using a definition of 97% sequence
identity. Community ecology statistical analyses demonstrate that the eastern
Atlantic Ocean bacterial assemblages are vertically stratified and associated
with water layers characterized by unique environmental signals (e.g.,
temperature, salinity, and nutrients). Genetic compositions of bacterial
assemblages from the same water layer are more similar to each other than to
assemblages from different water layers. The observed clustering of samples
by water layer allows us to conclude that contemporary environments are
influencing the observed biogeographic patterns. Moreover, the implementation
of a novel Bayesian inference approach that allows a more efficient and
explicit use of all the OTU abundance data shows a distance effect suggesting
the influence of historical contingencies on the composition of bacterial
assemblages. Surface bacterial communities displayed a general congruency
with the ecological provinces as defined by Longhurst with modest exceptions
usually associated with unique hydrographic and biogeochemical features.
Collectively, our findings suggest that vertical (habitat) and latitudinal
(distance) biogeographic signatures are present and that both environmental
parameters and ecological provinces drive the composition of bacterial
assemblages in the eastern Atlantic Ocean. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|