Bioprospecção de fungos filamentosos endofíticos de espécies medicinais com potencial de produzir moléculas de interesse biotecnológico

Abstract

Endophytic microorganisms are defined as organisms that live inside plant tissues without causing any damage to the host plant. Bacteria and fungi produce several bioactive compounds, with antimicrobial, enzymatic, antioxidant and other properties. These compounds may be derived from the ability of endophytic microorganisms to produce substances similar to those produced by the host plant. For these reasons, in this work was performed the bioprospection of endophytic filamentous fungi of native medicinal plants of the Brazilian tropical savanna, with the objective of testing their ability to produce compounds with antioxidant, anti-inflammatory and antimicrobial activity. The plant species used were Lafoensia pacari, Campomanesia xanthocarpa, Guazuma ulmifolia and Siparuna guianensis. Eighteen endophytic fungi were isolated and identified from the tissues of these plants. To obtain the bioactive compounds, the fungi were submitted to submerged culture in malt broth, Czapek Dox broth and potato dextrose broth and after growth submitted to centrifugation, the supernatants (crude extracts) were evaluated. Antimicrobial activity was observed in the isolate GF9C (family Trichocomaceae) obtained in the medium malt, the crude extract inhibited the growth of bacterial strains Staphylococcus aureus and Enterococus faecalis. Antioxidant activities greater than 50% tested in reaction with the free radicals 2,2- diphenyl-1-pricrilhydrazyl (DPPH) and 2,2-azino bis (3-ethylbenzo thiazoline 6 sulfonic acid) (ABTS) were obtained by isolated fungi LF3C (Talaromyces funiculosus), GF16F (Colletotrichum boniense), CF7F (Phomopsis sp) and GF9C (Trichocomaceae family) in Czapek Dox medium. The anti-inflammatory activity was tested by reaction with membranes of human erythrocytes and the isolates C7FF, LF3C and GF9C, and the last two presented activity indexes of 94.82% and 49.32%, respectively. The crude extracts of these isolates were promising and it was possible to relate the anti-inflammatory activity to the presence of flavonoids. The results obtained in general corroborate the ability of endophytic fungi to produce bioactive compounds, and the activities tested have biotechnological potential for future applications in medicine.