The present project, proposed for the Doctor degree of Lívia Soman de Medeiros, is intended to study the secondary metabolites produced by endophytic microorganisms isolated from guava and apple fruits. The literature shows some of this kind of work with these plants. However those studies deal with other organs such as leaf and roots, in more agronomic than chemistry point of view. The present work proposal is intended to study the microbiology/chemistry of the edible part of the fruits. The fungus Cladosporium uredinicola and two Penicillium species have already been isolated as endophytics from guava and apple fruits respectively, in previous studies performed in our research group. During these studies, it was observed that C. uredinicola is a great depside producer. Some of these compounds, isolated from the fungus cultivated under sterile medium, showed interesting antimicrobial activity against some tested bacteria, specially the bactericide activity against Pseudomonas aeruginosa and Bacillus subtilis. Another very interesting result was the detection, by LC-MS/MS experiments, of the same depsides produced by the fungus in guava pulp fruit. These results inspire the present research project in performing deeper studies about the microbiote of edible fruits. Focusing the possibility of bioactive natural products discovery, our mainly aim is to investigate the secondary metabolites most commonly produced by the endophytic fungus at conventional culture medium, as well as the study of induced metabolism of these microorganisms through modifications in the culture conditions, and finally to verify the ability of them in biotransforming substrates related to those endogenous metabolites present in fruits. The development of the project will require intense use of diverse chromatographic techniques, mass spectrometry and NMR spectroscopy. The establishment of a good background in these organic analyses and in the interpretation and contextualization of the results is the main educative aim in the MS project proposed for the student.
News published in Agência FAPESP Newsletter about the scholarship: