TY  - JOUR
A1  - Bachmann, Jennifer
A1  - Heimbach, Tabea
A1  - Hassenrück, Christiane
A1  - Kopprio, German A.
A1  - Iversen, Morten Hvitfeldt
A1  - Grossart, Hans-Peter
A1  - Gärdes, Astrid
T1  - Environmental Drivers of Free-Living vs. Particle-Attached Bacterial Community Composition in the Mauritania Upwelling System
JF  - Frontiers in microbiology
N2  - Saharan dust input and seasonal upwelling along North-West Africa provide a model system for studying microbial processes related to the export and recycling of nutrients. This study offers the first molecular characterization of prokaryotic particle-attached (PA; > 3.0 mu m) and free-living (FL; 0.2-3.0 mu m) players in this important ecosystem during August 2016. Environmental drivers for alpha-diversity, bacterial community composition, and differences between FL and PA fractions were identified. The ultra-oligotrophic waters off Senegal were dominated by Cyanobacteria while higher relative abundances of Alphaproteobacteria, Bacteroidetes, Verrucomicrobia, and Planctomycetes (known particle-degraders) occurred in the upwelling area. Temperature, proxy for different water masses, was the best predictor for changes in FL communities. PA community variation was best explained by temperature and ammonium. Bray Curtis dissimilarities between FL and PA were generally very high and correlated with temperature and salinity in surface waters. Greatest similarities between FL and PA occurred at the deep chlorophyll maximum, where bacterial substrate availability was likely highest. This indicates that environmental drivers do not only influence changes among FL and PA communities but also differences between them. This could provide an explanation for contradicting results obtained by different studies regarding the dissimilarity/similarity between FL and PA communities and their biogeochemical functions.
KW  - prokaryotes
KW  - biodiversity
KW  - microbial ecology
KW  - alpha diversity
KW  - Bray Curtis dissimilarity
KW  - temperature
KW  - salinity
KW  - 16S rRNA Illumina amplicon sequencing
Y1  - 2018
U6  - https://doi.org/10.3389/fmicb.2018.02836
SN  - 1664-302X
VL  - 9
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  -