Study of marine biofilms as bio-indicators of seawater quality in costal Mediterranean environments
Supervisors: BRIAND Jean-François, BOUCHUCHA Marc (IFREMER, Laboratoire LERPAC)
Biofilms correspond to the microbial communities that colonize surfaces, especially in the marine environment. Within this microbial community of marine biofilms, photosynthetic microorganisms, which are mainly diatoms, are very sensitive to variations in environmental conditions. In fact, species change depending on the pollutants (nutrients, organic or metallic pollutants) present in the water, which implies that knowledge of these communities can provide information on the quality of the water. Their freshwater congeners have already been widely used for bio-indication in rivers.
The thesis will therefore aim to study the potential of marine biofilms as a tool for bioindication of the quality of coastal Mediterranean water bodies. It is based on two complementary parts: (1) a study directly linked with the SUCHIMED sea campaign, operated by IFREMER, on the biofilms that will have colonized 150 A4 PE plates submerged from March 16 to July 7, 2021 at 50 sites along the 1800 km of the French Mediterranean coast and (2) additional in situ and / or laboratory experiments intended to better understand biofilm-pollutant interactions by carrying out a multidisciplinary approach that allows diatom communities analysis (metagenomics), bioaccumulation of pollutants (organic and metals) and the chemical composition of the EPS matrix (biochemical, metaproteomic and metabolomic composition).
Key words : marine biofilms, diatoms, bio-indication, coastal waters, pollution