Chronic Polyaromatic Hydrocarbon (PAH) Contamination Is a Marginal Driver for Community Diversity and Prokaryotic Predicted Functioning in Coastal Sediments.
Benthic microorganisms are key players in the recycling of organic matter and recalcitrant compounds such as polyaromatic hydrocarbons (PAHs) in coastal sediments. Despite their ecological importance, the response of microbial communities to chronic PAH pollution, one of the major threats to coastal ecosystems, has received very little attention. In one of the largest surveys performed so far on coastal sediments, the diversity and composition of microbial communities inhabiting both chronically contaminated and non-contaminated coastal sediments were investigated using high-throughput sequencing on the 18S and 16S rRNA genes. Prokaryotic alpha-diversity showed significant association with salinity, temperature, and organic carbon content. The effect of particle size distribution was strong on eukaryotic diversity. Similarly to alpha-diversity, beta-diversity patterns were strongly influenced by the environmental filter, while PAHs had no influence on the prokaryotic community structure and a weak impact on the eukaryotic community structure at the continental scale. However, at the regional scale, PAHs became the main driver shaping the structure of bacterial and eukaryotic communities. These patterns were not found for PICRUSt predicted prokaryotic functions, thus indicating some degree of functional redundancy. Eukaryotes presented a greater potential for their use as PAH contamination biomarkers, owing to their stronger response at both regional and continental scales.
Equipe Environnement et Microbiologie, Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux, UMR 5254 CNRS - Université de Pau et des Pays de L'Adour Pau, France.
Mathilde
M
Jeanbille
Equipe Environnement et Microbiologie, Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux, UMR 5254 CNRS - Université de Pau et des Pays de L'Adour Pau, France.
Jérôme
J
Gury
Equipe Environnement et Microbiologie, Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux, UMR 5254 CNRS - Université de Pau et des Pays de L'Adour Pau, France.
Robert
R
Duran
Laboratoire Biogéochimie des Contaminants Organiques, Unité Biogéochimie et Ecotoxicologie, Département Ressources Biologiques et Environnement, Ifremer Centre Atlantique Nantes, France.
Jacek
J
Tronczynski
Laboratoire d'Océanographie Microbienne, Sorbonne Universités, CNRS, Université Pierre-et-Marie-Curie, UMR 7621, Observatoire Océanologique Banyuls-sur-mer, France.
Jean-François
JF
Ghiglione
Littoral, Environnement et Sociétés, UMR 7266 CNRS - Université de La Rochelle La Rochelle, France.
Hélène
H
Agogué
Laboratoire de Bio-surveillance de l'Environnement, Faculté des Sciences de Bizerte Zarzouna, Tunisia.
Olfa Ben
OB
Saïd
Laboratoire Microorganismes: Génome et Environnement, UMR 6023 CNRS - Université Blaise Pascal Aubière, France.
Najwa
N
Taïb
Laboratoire Microorganismes: Génome et Environnement, UMR 6023 CNRS - Université Blaise Pascal Aubière, France.
Didier
D
Debroas
Processus de Transferts et d'Echanges dans l'Environnement, EA 3819, Université de Toulon La Garde, France.
Cédric
C
Garnier
Marine Biodiversity, Exploitation and Conservation, UMR CNRS 9190 Montpellier, France.
Jean-Christophe
JC
Auguet
PAH; chronic contamination; coastal sediment; functional diversity; microbial communities