Research Objectives & Activities
What do we want to know?
Question 1 Do excreted metabolites have different structural and biological/antimicrobial properties compared to those remaining in the sponge biomass?
Question 2 Can we obtain sufficient quantity of bioactive/structurally novel metabolites through the concentration of excreted elements in order to pursue antimicrobial drug discovery?
OBJECTIVES & Technical approaches
Objective 1: Isolation of sponge cells and characterization of their composition in specialized metabolites
Sponge cells (microsymbionts and specialized cells) will be separated from the biomass and isolated using standardized and well-documented density gradient centrifugation methods. DNA metabarcode and microscopy analyses are also implemented to identify each group of cells and characterize the microbial diversity.
Objective 2: Concentration and characterization of sponge’s metabolites released in seawater
Multi-modal methods are implemented to concentrate as many released metabolites as possible from sponges maintained in aquarium. The key challenge is to optimize the quantity of collected metabolites that are diluted in trace amounts in seawater. For that purpose, technics relying on solid phase adsorption, using polymeric resins as adsorbent, are further adapted to the aquarium settings.
Objective 3: Systematic evaluation of anti-microbial properties
A sponge extract library is currently developed with extracts, from sponge biomass, separated sponge cells and excreted elements (exometabolites). Such a unique library facilitates the implementation of comparative bioassays.
The antimicrobial properties are evaluated in collaboration with researchers in charge of bioassay screening platforms at Aix-Marseille University:
natural product chemistry and data sharing
We are implementing MS-based analytical workflows designed to facilitate the structural dereplication of (exo)metabolites and promote an easy raw data sharing.
Likewise, the raw NMR data of all isolated metabolites whether their structure is already known or not are and will be made publicly accessible according to FAIR practices.
For NMR analyses, we are working closely with Dr. Gaëtan Herbette (Spectropole FR1739) and Dr. Olivier Bornet in charge of the 600 MHz with cryoprobe available at the Institut de Microbiologie de la Méditerranée (IMM, CNRS, Joseph Aiguier).