EFS12- Book of abstracts - Contact

SESSION 2: SECONDARY METABOLITES – BIOCHEMISTRY,
BIOSYNTHESIS, FEED AND FOOD SAFETY
Fusarium graminearum in depth: a novel method to
identify new metabolites by isotopic labelling and
high resolution mass spectrometry
P. M. Cano 1,2 , E. Jamin 1 , S. Tadrist 1 , P. Bourdaudhui 1 , M. Péan 3,4,5 , L.
Debrauwer 1 , I. P. Oswald 1,2 , M. Delaforge 6 , O. Puel 1,2
1 INRA, UMR 1331, Toxalim, Research Center in Food Toxicology, F-31027 Toulouse, France;
2 Université de Toulouse, INP, Toxalim, F-31076 Toulouse, France; 3 CEA, DSV, IBEB, Groupe de
Recherches Appliquées en Phytotechnologie, F-13108 Saint-Paul-les-Durance, France; 4 CNRS, UMR
Biologie Végétale & Microbiologie Environnementale, F-13108 Saint-Paul-les-Durance, France; 5 Aix-
Marseille Université, F-13108 Saint-Paul-les-Durance, France; 6 CEA Saclay, iBiTec-S, SB2SM and
URA CNRS 8221, F-91191 Gif sur Yvette, France
E-mail: paty.canog@gmail.com
Characterization of fungal secondary metabolomes has become a challenge of
great interest in the last decades due to the emergence of fungal threats to
natural ecosystems and public health; and also due to the industrial interest of
many of these molecules. In view of this, the aim of the present study was to
develop an integrated approach to analyse fungal metabolomes. The method we
present hereby combines high resolution mass spectrometry and double isotopic
labelling which efficiently enabled the unambiguous determination of exact
chemical formulas, getting rid of problems coming from interference of nonbiological
molecules. More precisely, the Aspergillus fumigatus strain NRRL
35693, an extremely hazardous human pathogen and the Fusarium graminearum
strain PH1, a devastating plant pathogen, were grown on wheat grains (Triticum
aestivum) with different isotopic enrichments: (1) naturally enriched grains, (2)
grains enriched 96.88% 13 C, (3) grains enriched with 53.37% 13 C and 96.8% 15 N.
Methanol extracts of each culture was then analysed by reversed phase liquid
chromatography coupled to LTQ-Orbitrap mass spectrometer. Data of the 3
cultures were cross-analysed with an in-house developed software. Metabolites
were characterized with the metabolite database, Antibase 2012, annotated with
MS/MS experiments and identified by comparison with standards when possible.
The method was firstly successfully validated with the well-known metabolome of
Aspergillus fumigatus. Application of the method on the metabolome of Fusarium
graminearum allowed the characterization of 37 new compounds including
fusaristatin A which had never been isolated from this specie before, bringing a
new perspective on the toxicity of this fungus. This kind of analysis will
undoubtedly facilitate the study of fungal metabolomes.
Keywords: Fusarium graminearum, metabolome, isotopic labelling, HPLC-FT-MS
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