- The impact of long-term hydrocarbon exposure on the structure, activity, and biogeochemical functioning of microbial mats doi link

Auteur(s): Aube Johanne, Senin Pavel, Pringault Olivier, Bonin P., Deflandre Bruno, Bouchez Olivier, Bru Noelle, Biritxinaga-etchart Edurne, Klopp Christophe, Guyoneaud Remy, Goni-urriza Marisol

(Article) Publié: Marine Pollution Bulletin, vol. 111 p.115-125 (2016)

Ref HAL: hal-01439616_v1
DOI: 10.1016/j.marpolbul.2016.07.023
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Photosynthetic microbial mats are metabolically structured systems driven by solar light. They are ubiquitous and can grow in hydrocarbon-polluted sites. Our aim is to determine the impact of chronic hydrocarbon contamination on the structure, activity, and functioning of a microbial mat. We compared it to an uncontaminated mat harboring similar geochemical characteristics. The mats were sampled in spring and fall for 2 years. Seasonal variations were observed for the reference mat: sulfur cycle-related bacteria dominated spring samples, while Cyanobacteria dominated in autumn. The contaminated mat showed minor seasonal variation; a progressive increase of Cyanobacteria was noticed, indicating a perturbation of the classical seasonal behavior. Hydrocarbon content was the main factor explaining the differences in the microbial community structure; however, hydrocarbonoclastic bacteria were among rare or transient Operational Taxonomic Units (OTUs) in the contaminated mat. We suggest that in long-term contaminated systems, hydrocarbonoclastic bacteria cannot be considered a sentinel of contamination