Fungi of the genus Trichoderma are prevalent components of different ecosystems in a wide range of climatic zones. Many species of the genus Trichoderma have been extensively investigated, because they can produce extracellular enzymes and antifungal antibiotics1. Two main types of metabolites secondary can be identified: low molecular weight and volatile metabolites and high molecular like peptaibols2.
In the present work, we investigated whether MALDI-TOF MS analysis of secondary metabolites mass fingerprints of fungus endophytic Trichoderma spp, aiming to better understand the production of these compounds by the genus. The identification of these compounds may in the future help to elucidate processes involved in the biosynthesis of these molecules. Although several metabolites are isolated and identified from Trichodemas spp, the production of these compounds between the lineage is not identical. From this context, the need to investigate the collection of Trichodermas isolated in the LabioMMI, and to identify the production of secondary metabolites by a fast method like MALDI-TOF mass spectroscopy. The fungus used in the present study was endophytic fungi isolated from the leaves of several plants. The leaf samples were surface-sterilized by following the protocol described by Pereira et al. The MALDI-TOF spectra of the Trichoderma spp collection were performed in positive linear mode in the range of 2-20kDa mass-to-charge ratio (m/z). The groupings produced by the fingerprints of the analyzed fungi show significant differences between the individuals that compose the collection, so that 4 distinct groups can be observed: G1 (873, 878, 880, 882, 883), G2 (169, 171), G3 (779, 780, 782) and G4 (PC0310, PC0311) and this result demonstrates the high similarity between the fingerprints of the fungi that make up each grouping. The same collection of Trichoderma spp. may be differentiated relative to its metabolomic fingerprint of MALDI-TOF spectra acquired in the positive ionization mode in the region of 600 to 3500 Da. The isolate PC0310 has the fingerprint highly correlated with the G1 evidencing that two distinct species produce the same classes of compounds in the region of 600 - 3500 Da and it is possible to identify which ions can be used as biomarkers to separate each fungal grouping. The groupings composed of fungi 873, 878, 880, 882, 883 and PC0311 are characterized by the unique presence of compounds in the mass region of 600 to 700 Da that can be attributed to peptaibols. The analysis of mass ions spectra from intact cells provides a comprehensive picture of the metabolic products of a given sample, with, possibly, a good discrimination of isolates.