Exposé Chercheur Invité

Financeur du projet: CNRS, ANR, Labex CEBA, DIM MAP, DIM Analytics
Employeur: CNRS
Titre: Mass Spectrometry for chemical ecology

David TOUBOUL (Université Paris-Saclay) Véronique EPARVIER (CRNS).

Among modern analytical tools, Mass Spectrometry (MS) offers a large variety of applications, including proteomics and metabolomics. In particular, due to high mass resolution and precision measurements, together with tandem MS for structural characterization, MS emerged as a gold standard for the study of specialized metabolites.
Three main developments performed through collaborations at ICSN will be introduced here:
- MS classification of bacterial strain by MALDI-TOF fingerprint (biotyping): after short time of cultivation, lipid or protein extract can be performed from a single Petri dish in order to acquire a MS fingerprint and compare them to database or from each other. This classification is efficient and fast to classify microorganisms showing same phenotypes before genomic identification [1].
- Molecular network: dereplication is one of the crucial step to identify known specialized metabolites and to focus research tasks on unknown ones. LC-MS/MS is highly efficient to separate, detect and elucidate partial structures of specialized metabolites. In order to decipher the large amounts of generated data, molecular network is becoming unavoidable in this field. Several examples related to the use of MetGem Software developed at ICSN will be introduced [1,2].
- Mass Spectrometry Imaging: MS imaging allows determining the distribution of metabolites on biological surfaces including transfers of Petri dishes at a resolution of fen tens of micrometers. In particular, accumulated versus released compounds can be imaged and competition experiments can be surveyed at different time scales [3].
All these techniques are now available for chemical ecology leading to emerging interdisciplinary projects.

[1] Barthelemy M et al., Sci. Rep. in press, DOI: 10.1038/s41598-020-74852-w
[2] Olivon et al, Anal. Chem. ; 90(23): 13900-13908.
[3] Vallet et al, J. Nat. Prod. ; 80(11): 2863-2873.

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