PhD thesis defense of Abel BARRE
Abel BARRE, PhD student at MAPIEM lab, under the supervision of:
- BRIAND Jean-François,
- BOUCHOUCHA Marc (Cadre de recherche, IFREMER)
has defended his PhD thesis in, specialty "Marine Microbial Ecology" , on the topic:
on December 12, 2025, at 9:00AM, the Amphitheatre of Building A, IUT, University of Toulon.
The jury was composed of:
- Mme Daniela BĂNARU, Maître de conférences – HDR, Aix-Marseille Université, Rapporteur
- M. Pascal CLAQUIN, Professeur des universités, Université de Caen Normandie, Rapporteur
- M. Frédéric RIMET, Ingénieur de recherche – HDR, INRAE, Université Savoie-Mont Blanc, Examinateur
- M. Jean-François GHIGLIONE, Directeur de recherche, CNRS, Sorbonne Université, Examinateur
- M. Marc BOUCHOUCHA, Cadre de recherche, IFREMER, Co-encadrant de thèse
- M. Jean-François BRIAND, Professeur des universités, Université de Toulon, Directeur de thèse
- M. Pierre BOISSERY , Expert eaux côtières et littoral méditerranéen, Agence de l’Eau Rhône-Méditerranée-Corse, Invité
Abstract
Biofilms consist of prokaryotic and eukaryotic microbial communities colonizing all submerged biotic and abiotic surfaces, particularly in coastal marine environments. Their cohesive exopolymeric matrix is known to accumulate chemical contaminants, but its representativeness of the surrounding environment remains unknown. Diatoms (Bacillariophyta), a dominant autotrophic component of marine biofilms that has been little studied, are used as bioindicators in continental waters, but their potential in marine environments remains unexplored.
The work carried out in this thesis has made it possible, on the one hand, to characterize the relationships between biofilm properties and the accumulation of organic and metallic contaminants and, on the other hand, to compare the ability of biofilm to reflect coastal chemical contamination with that of other reference matrices. This work provides a critical assessment of biofilm as an indicator of coastal chemical contamination. In addition, multiscale spatio-temporal approaches in situ have made it possible to rank the influence of environmental parameters, particularly contaminants, on the diversity and structure of diatom communities characterized by an innovative metabarcoding approach in the marine environment.
This work provides a better understanding of the determinism of diatom communities in marine biofilms and highlights the potential of biofilms for bioindication of chemical quality in coastal marine environments.
Keywords
marine biofilms, diatoms (Bacillariophyta), bioindicators, chemical contamination, metabarcoding
