Antimicrobial activity of crude extracts of endophytic fungi isolated from medicinal plant Sapindus saponaria L.

Abstract

Endophytic microorganisms are fungi or bacteria which live inside plant tissues or organs, without causing them any harmful symptoms. They may protect the plant from insect attacks and diseases, being also able to produce substances of biotechnological interest. Sapindus saponaria L. is a tree commonly known in Brazil as "sabão-de-soldado". In folk medicine, its bark, root and fruit are used as producing anxiolytic, astringent, diuretic and expectorant substance, as well as tonic, blood depurative and cough medicine. Its leaves extracts present properties that neutralize bleeding. The fruit extract presents antifungical and larvicidal activities. The aim of the present work was to investigate biotechnological potential of crude extracts of fungal endophytes (G2-20 Cochliobolus intermedius, G1-74 non-identified - NI, G22-97 Phomopsis sp. and G23-100 NI) isolated from S. saponaria, that have been assayed against five pathogenic bacteria. The antibacterial activities with extracts obtained from the four endophytic lineages were promising, since all of them inhibited the growth of at least one of the tested bacteria. One metabolite, extracted from the lineage G2-20 (Cochliobolus intermedius) presented activity for all the bacteria tested. The results showed that S. saponaria isolates presented biotechnological potential for the control of pathogenic bacteria tested in vitro.