Antibacterial Potential of Endophytic Fungi from Xylopia aethiopica and Metabolites Profiling of Penicillium sp. XAFac2 and Aspergillus sp. XAFac4 by GC-MS

Abstract

Endophytes exist without harming the tissue of plants. They manufacture a lot of chemicals for use in pharmaceuticals. Xylopia aethiopica (Dunal) A. Rich. is a member Annonaceae family, an indigenous medicinal plant in Nigeria. The variety and antibacterial properties of the fungal endophytes that inhabit its fruit are poorly understood. The isolation, molecular description, phylogenetic analysis, and antibacterial effectiveness of its fungal endophytes were thus the main objectives of this study. Standard methods were used to isolate the endophytes, and partial sequencing of the internal transcribed spacer (ITS) region of the rDNA was used to identify them before phylogenetic analysis. Using version X of the Molecular Evolutionary and Genetic Analysis (MEGA) tool, the phylogenetic tree was created using the neighbour-joining method. The tree was further annotated using the interactive tree of life (iTOL) version 6.0. The antibacterial activity of the fungal endophytes was studied using both perpendicular streaking and agar well diffusion assays. The Gas Chromatography-Mass Spectrometry (GC-MS) assay was used to identify some of the chemicals in the extracts. A total of 4 fungal endophytes were recovered. They were identified as Scopulariopsis sp. XAFac1, Penicillium sp. XAFac2, Aspergillus sp. XAFac3 and Aspergillus sp. XAFac4. Only Penicillium sp. XAFac2 and Aspergillus sp. XAFac4 exhibited good antibacterial activity. The most prominent compounds obtained from their extracts included 9-octadecanoic acid, methyltetradecanoate, dodecanoic acid, pentadecanoic acid, 5-tetradecene, 5-octadecene, trichloroacetic acid, and trifluoroacetoxyhexadecane. These results provided important knowledge on the diversity of endophytic fungi inhabiting X. aethiopica fruit and could be exploited as a novel source of bioactive compounds.