Avaliação química e biológica dos extratos acetato de etila obtidos a partir do co- cultivo dos fungos Lasiodiplodia sp. e Preussia africana

Abstract

Endophytic fungi, characterized by constituting a class of microorganisms that can reside in the internal tissues of plants without causing damage to their hosts, produce a large number of bioactive substances. Co-cultivation, a technique used for the production of natural substances or to activate clusters of silent genes responsible for the biosynthesis of secondary metabolites, has been widely used to obtain promising results in obtaining new molecules. In this context, the objective of this work was to carry out the co-cultivation of endophytic fungi isolated from the leaves of Handroanthus impetiginosus so that these fungi were able to produce novel secondary metabolites with pronounced biological activity. In order to carry out this work, in addition to being isolated in standard Czapek medium, Lasiodiplodia sp. and Preussia Africana fungi were cultivated together, in liquid medium, both in static and stirred mode. Ethyl acetate organic extracts, after solvent evaporation, were evaluated for their antimicrobial and antioxidant potential. The chemical profile was evaluated by thin layer chromatography and also by nuclear magnetic resonance. The best results for the assay of minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) were for the co-cultivation of Lasiodiplodia + Preussia fungi extracts in agitated medium after 7 days, and single culture of Preussia in stirred medium, both with MIC values ​​between 200-400 µg.mL -1 against Staphylococcus aureus. Regarding the antioxidant activity, the pure extract of Preussia showed high antioxidant activity when evaluated by DPPH, total phenolics and FRAP analyses. For the co-culture, strong antioxidant activity was demonstrated for the extract of the co-cultures of Lasiodiplodia + Preussia in static medium and Lasiodiplodia + Preussia in stirred medium in 7 days by total DPPH and phenolic assays. The results of FRAP for mixed culture Lasiodiplodia + Preussia in stirred medium in 15 days, showed higher antioxidant activity compared to the others. Thus, the co-cultures of microorganisms can improving the yield of bioactive substances, contribute to the antimicrobial potential and increase the antioxidant activity of the extracts.