The microorganisms get great part of the construction units of its structures, essential machineries for its survival, from the substrate in which they develop themselves. Sugars and micronutrients are composites important for microorganisms to construct its cellular walls and others organs that characterize them as livings creature. Therefore, many fruits rich in saccharides and other important chemical constituents are important substrates for the lodging of many fungi and bacteria. Although only few studies have been done on biochemistry of these different phases of microorganism-plant associations, it has been observed that the metabolism of microorganisms can be active producing substances that accumulate in the host plant. These substances can have diverse effect in the human beings according the type/species of the producing microorganism. The present project, considered for the student Mariana Fioramonte, aims to study the production of secondary metabolites by microorganisms found in apple (Malus domestica). The literature shows that apple cultures suffer from post-harvest and storage problems due to susceptibility of the fruits to some fungal disease. Alternaria alternata is one of these fungi that can cause fruit rottenness. A series of carcinogenic mycotoxins can be produced by fungi of this genus, although strains isolated from apple has not yet been investigated. Patulin, a neurotoxic and mutagenic mycotoxin, has been considered a terrible problem of contamination in apple juices. The present proposal of works aims at the study of chemical/microbiology of the edible part of apple fruits. Our main objective is to isolate endophytic microorganisms; to verify its potential of production of secondary metabolites in artificial medium and culture medium containing the fruit pulp; and, finally, to detect these compounds in the fruits. In preliminary works, a sampling of the microbiota of apples was already made, as well as some chemical studies already had been initiated. The development of the project will require intensive use of diverse chromatographic techniques, mainly HPLC with mass spectrometry detection. This improvement in organic analyses, as well as the interpretation and contextualization of the results is the goals of formation for the stage of scientific initiation proposal for the pupil M. Fioramonte.
News published in Agência FAPESP Newsletter about the scholarship: