EBSI Team | Metabolimics
Table of contents
Current team members:Aurore Michaud, Estelle Martineau, Jonathan Farjon, Serge Akoka, Patrick Giraudeau*
Past members: Adrien le guennec, Jérémy Marchand
Collaborations (past and present): Catherine Deborde and Annick Moing (INRA Bordeaux), Gaud Dervilly-Pinel and Yann Guitton (LABERCA Nantes), Olivier Grovel and Yves-François Pouchus (MMS Nantes), Jean-Charles Portais (INSA Toulouse)
While NMR-based metabolomics studies are mostly performed with 1H 1D NMR, the latter suffers from the severe and numerous peak overlaps characterizing complex biological samples. In this context, we are evaluating the potential of various 2D NMR approaches for a variety of targeted and untargeted metabolomics applications. Fast and repeatable 2D NMR methods are indispensable in this field, not only for the sake of high-throughput analysis, but also to reduce the impact of hardware instabilities and consequently improve the precision.
Multi-dimensional methods based on ultrafast 2D NMR or non-uniform sampling have already been applied in different fields through past and current collaborations. These applications include the targeted quantification of polar metabolites in tomato extracts at different development stages, or the untargeted lipidomics analysis of the effect of a growth promoter in meat. A similar strategy has been applied on a benchtop spectrometer, showing that the authentication of food products through untargeted strategies can be significantly improved by incorporating fast 2D NMR methods in the analytical workflow.
Supported by: Région Pays de la Loire (RFI Food 4.2 Lipidotool), Biogenouest (CORSAIRE platform)
Current team members: Dylan Bouillaud, Benoît Charrier, Patrick Giraudeau, Jonathan Farjon*
Collaborations (past and present): Olivier Gonçalves, Jérémy Pruvost and Jack Legrand (GEPEA, Univ. Nantes)
Microalgae are usually detected by cytometry at the cell scale, or by Infra-red and Raman spectroscopies but these techniques fail to detect intra-cellular chemicals due to the signal of the culture water.
In this context, we are exploring the potential of multiscale NMR for the analysis of microalgae cells and their lipidic extracts. The main challenge is to identify and quantify lipids in microalgae aqueous cultures. With this aim, high field NMR provides the best sensitivity and resolution to decipher complex lipidic extracts. Moreover, benchtop NMR has a great ability for real time online monitoring of bioprocesses such as the accumulation of lipids in microalgae during a nitrogen starvation in photobioreactor. Recent improvements in LF NMR pulse sequences, especially in solvent suppression and ultra-resolved NMR are promising for profiling the lipidic metabolism of microalgae.
Supported by Région Pays de la Loire (Pari scientifique AMER-METAL), CNRS (Projet interdisciplinarité RMN-(ME)2-TAL).
Current team members: Lenny Haddad, Vincent Portaluri, Virginie Silvestre, Mathilde Grand, Patrick Giraudeau, Serge Akoka, Gérald Remaud*.
Past team members: Ghina Hajjar, Denis Loquet, Boris Gouyeux, Sophie Guyader, Noëlle Merchack. Collaborations: J. Bejjani, T. Rizk (Saint-Joseph University, Beirut, Lebanon), F. Thomas, E. Jamin (EUROFINS, Nantes, France),
We apply high-field NMR combined with advanced statistical analysis methods for the profiling of complex samples (biological fluids, extracts, foodstuffs, etc.). This profiling approach forms part of our “omics” expertise as a member of the CORSAIRE metabolomics core facility (part of the Biogenouest network). Profiling tools include 1D 1H and 13C NMR, but also innovative fast 2D NMR methods. These approaches are applied both at high-field and on bencthop NMR spectrometers.
Beyond the classical ”omics” workflow, particularly original work concerns the development of profiling methods for lipid mixtures as found in edible fats. Such mixtures may be authenticated by the metabolic profile but also by the determination of the isotopic profile of major components. We show that a combined 13C-isotopomics and metabolomics approach presents many advantages: no need for prior chemical manipulations, determination of the positional distribution of major fatty acids on the glycerol backbone of triglycerides, and measurement of the relative position-specific isotopic 13C content at different chemical sites.
Furthermore, all this information is obtained from the same spectrum in a few minutes. This method has been compared with 1H profiling and gas chromatography. Its higher efficiency is explained by a significant contribution of variables that can only be obtained by this technique. Generally speaking, 13C profiling enables the classification of all types of edible fats. References:
Supported by: National Council for Scientific research of Lebanon, Saint-Joseph University of Beirut, EUROFINS Nantes, National Council for Scientific research and University of Nantes.