In vitro Antibacterial Activity of Crude Extracts Produced by Endophytic Fungi Isolated from Piper hispidum Sw.

Endophytic fungi inhabit the interior of plants without causing apparent harm to them and constitute an alternative for the control of human pathogens, since they can synthesize bioactive compounds. The plant Piper hispidum Sw. has several medicinal properties and harbors a diversity of endophytes. In this present study, four endophytic fungi from P. hispidum were used for obtaining crude ethyl acetate extracts that were tested against Enterococcus hirae, Escherichia coli, Micrococcus luteus, Salmonella typhi and Staphylococcus aureus, using cup plate technique. The obtainment resulted in crude ethyl acetate extracts with a final concentration between 19.9 and 61.4 mg/ml. the antibacterial tests presented satisfactory results, where the pathogenic bacteria were inhibited by the four extracts tested, except for E. hirae that was inhibited by two extracts. Means of inhibition halos ranged from 9.42±0.63 to 14.08±1.70 mm. Analysis of variance showed that the extract produced by endophyte Lasiodiplodia theobromae was the most effective against all bacteria except for S. typhi, which was more inhibited by the extract of an endophyte from Diaporthales order. Therefore, this study indicates that endophytes from medicinal plant P. hispidum could be potential sources of antibacterial substances, with emphasis on L. theobromae.

Antimicrobial Activity of Crude Extracts of Endophytic Fungi Isolated from Medicinal Plant Sapindus saponaria L.

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 “sabãode- 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.