Metabolome profiles of moulds on carton-gypsum board and malt extract agar medium obtained using an AuNPET SALDI-ToF-MS method

- AuNPET LDI allowed identification of 89 moulds metabolites/48 metabolomic pathways.
- Moulds metabolites vary in mono and mixed culture, and on CGB and MEA medium.
- Moulds metabolism on building materials tend to steroid and terpenoid-quinone synthesis.
- AuNPET LDI-ToF-MS can be useful for mould metabolites analysis in building material.

The aim of this study was to compare the metabolite profile of the moulds Alternaria, Aspergillus, Cladosporium, Penicillium, Stachybotrys, and Trichoderma under model conditions on MEA (malt extract agar) medium and carton-gypsum board (CGB). This was followed by comparison of the metabolite profile of each particular strain and of a mixed culture of all moulds together. Metabolome analysis was performed using a high-resolution surface assisted laser desorption/ionization time-of-flight mass spectrometry based on a gold nanoparticle-enhanced target (AuNPET SALDI-ToF-MS) imaging method. All water extracts tested showed the presence of compounds with molecular weights in the range of 80-2000 m/z (mass-to-charge ratio). On CGB, the results obtained showed the existence of 299-453 peaks with higher intensity and 351-487 peaks with lower intensity compared to the peaks obtained from MEA, depending on the mould species. A distinct change in the metabolite profile under the influence of the growth medium was observed for the mixed culture on the MEA medium. The profile showed ∼200 peaks with higher intensities of metabolites within m/z ranges 80-300 and 450-600; for the culture growing on CGB, the peak intensity was within m/z 300-450, and the number of peaks was 600-750. A new metabolomic methodology allowed the identification of 89 metabolites belonging to 48 metabolomic pathways. Compounds belonging to the citrate cycle and penicillin and cephalosporin biosynthesis pathways were identified on MEA. On CGB moulds, the metabolism changed to steroid, ubiquinone and other terpenoid-quinone biosynthesis.