Diversity and antibacterial potential of endophytic fungi cultivable from triplaris gardneriana wedd. Leaves

Abstract

Triplaris gardneriana (Pajeu) is a tree species belonging to the Polygonaceae family that occurs in areas of the Caatinga, although it is not exclusive to this biome. Several parts of this plant are widely used by traditional communities in the treatment of sick parties. Endophytic fungi, which live inside plant tissues without causing any harm to the host, can secrete secondary metabolites with similar characteristics from the host. No studies were found that addressed the endophytic biota of this species, so the objective of this work was to isolate, identify and estimate the diversity of endophytic fungi of T. gardneriana. As well as evaluating the antibacterial potential of these fungi in relation to Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923). The material was collected in October 2022 at three different points in the municipality of Petrolina, Pernambuco. The leaves were taken to the Laboratório de Microbiologia at the Headquarters Campus of the Universidade Federal do Vale do São Francisco where they were processed for isolation. The identification was observed observing the macro and microscopic characteristics. The well diffusion technique was used to estimate the antibacterial potential. 131 endophytic fungi were recovered, three belonging to the Mucoromycota phylum and 128 to the Ascomycota phylum. Resulting in 33 taxa, where 23 were identified at genus level, most belonging to the genus Aspergillus spp (51%) followed by Alternaria sp. (22%) and Penicillium sp. (4%). Regarding the antibacterial action analyses, one isolate (Aspergillus sp6) presented an inhibition halo (12mm) for Escherichia coli, while five other isolates (Aspergillus fumigatus, Aspergillus sp 5, Aspergillus sp7, Curvularia sp. and Trichoderma sp2) presented inhibition for Staphylococcus aureus, with inhibition halos varying between 8 and 13.5mm. This was one of the first works to correlate an antibacterial action attributed to pajeú to endophytic fungi present in its leaves. In addition to estimating the diversity of these endophytes. Being useful for carrying out new biotechnological studies involving this tree species.