Interplay between microorganisms and contaminants

Moderator : Léa Cabrol

 

Our goal is to understand the mutual influences between contaminants and marine microorganisms, at both population and molecular levels. Historically, a solid expertise has been acquired in the team on organic contaminants (such as hydrocarbons), which has been supplemented in recent years by an expertise on inorganic contaminants such as metallic trace elements.

The studies developed in this area aim to include :

  • Effect of contaminations on the biodiversity and the microbial community activity
  • The contribution of these communities to the dynamics and fate of contaminants.

Our objects of study are mainly natural ecosystems (coastal environment under anthropic influence), as well as bioremediation processes aiming to reduce the impact of industrial discharges at sea. This topic is closely associated with the cross-disciplinary axis CONTAM of the MIO, which brings together chemists, physicists and biologists.

 

Examples of studies

Hydrocarbures

 

Figure : Mangrove Ecosystem Guyana (1), monitoring of biodegradation of a crude oil (2); study in mesocosm of the fate of crude oil in brine after 106 days of incubation at in situ temperature and lighting (3).

 

We study the degradation and transformation of hydrocarbons in the mangroves of Guyana, taking into account the network of interactions between micro-, meio- and macro-fauna benthic.

Metals and Metalloïds

 

Gulf of Gabes (Tunisia) and in vitro experiment of resuspension of contaminated marine sediments.Gulf of Gabes (Tunisia) and in vitro experiment of resuspension of contaminated marine sediments.

 

First, we identify the microorganisms responsible for the methylation of mercury, generating a highly toxic compound in various marine environments (Black Sea, Mediterranean, Pacific). We are also interested in the microorganisms involved in the processes of redox states and im/mobilization of a cocktail of metals in heavily anthropized ecosystems (Toulon harbor). In particular, we evaluate the impact of phosphogypsum releases in the Gulf of Gabes (Tunisia) during the resuspension of marine sediments and we identify the key players potentially involved in metal immobilization, with a view to possible applications in bioremediation (topic 5). This is achieved in partnership with CBS (Sfax, Tunisia) in the framework of LMI COSYSMED.