Antifungal Activity from Stem Extract and Endophytic Fungi of Opuntia humifusa (Raf.) Raf
Endophytic microorganisms are fungi or bacteria that live inside plant tissues or organs, without causing any harmful symptoms. They may protect the plant from insect attacks and diseases, being also able to produce substances of biotechnological interest. Plants in the genus Opuntia are members of the Cactaceae family that are widely distributed in semiarid countries throughout the world, especially in the Mediterranean and Central America. Opuntia humifusa have been extensively characterized biochemically, and their biological effects, which include therapeutic properties as anticancer, antimicrobial, antioxidant and anti-inflammatory effects and potential hypoglycemic and hypolipidemic activity, have been well documented. The aim of the present work was to investigate antifungal potential of 30 dichloromethane (DCM) crude extracts of stem's O. humifusa and 80 DCM crude extracts of fungal endophytes isolated from O. humifusa against the phytopathogens Colletotrichum acutatum, C. fragariae, and C. gloeosporioides at a concentration of 160 µg/mL by bioautography assay. A total of 6 extracts (7.5%) of fungal endophytes showed antifungal properties with zones of inhibition ranging from 5 to 16 mm. No antifungal activity was observed in the crude extracts from plants. The results showed that O. humifusa isolates presented biotechnological potential for the control of phytopathogens fungi tested in vitro. The characterization of the extract and the substance bioactive will be performed using the technique of de-replication is of paramount importance for the detection of antifungal metabolites prototype for the development of new pesticides selective and less toxic to the environment. Acknowledgements: Capes Foundation.