Biotechnological potential of the endophytic fungi isolated from Clitoria guianensis

The biodiversity of endophytic fungi in the Cerrado region in the north of Brazil remains largely unexplored, however it is important to explore the biotechnological potential of these endophytes. In this study, we isolated seventeen endophytic fungi strains from the medicinal plant Clitoria guianensis and tested the ability of these strain to inhibit the phytopathogenic fungi: Fusarium oxysporum, Bipolaris oryzae, and Curvularia lunata. The in vitro antagonistic assay was evaluated on different time scales (six and twelve days), we observed that all strains of endophytic fungi, isolated from C. guianenses, inhibited the growth of F. oxysporum and B. oryzae after six days, for C. lunata just ten strains inhibited its growth in the first six days. In twelve days, only the strains CGF1, CGF3, and CGF4 inhibited the growth of F. oxysporum, while for the other phytopathogenic fungi the inhibitions were not observed. The endophytic fungi were cultivated in a controlled environment using potato dextrose broth (PDB) medium and the crude extracts were obtained by extracting the fungi culture with ethyl acetate (EtOAc). All the crude extracts exhibited antioxidant activity, as assessed by the 2,2 diphenyl-1-picrylhydrazyl (DPPH) method. Additionally, four different concentrations (C100, C500, C1000 and C2000) of the crude extracts were evaluated in the in vitro allelopathic assay using Lactuca sativa (lettuce) seeds. Some fungal extracts demonstrated allelopathic effects by inhibiting the growth of Lactuca sativa seedlings, for example, the crude extract obtained from the strain CGF7 at a concentration of C2000 inhibited radicle development by 75.2%. While others acted as growth promoters, as is the case with the crude extract of the CGF10 strain, which contributed to lettuce radicle growth by 15.9% in C2000. Overall, these findings suggest that endophytic fungi associated with C. guianensis have significant biotechnological potential and can be used as biocontrol agents against phytopathogens and specific plants, in addition to growth promoters, making them valuable tools for sustainable agriculture.