Histologic observation, identification, and secondary metabolites analysis of endophytic fungi isolated from a medicinal plant, hedychium acuminatum Roscoe

Abstract

Some endophytic fungi live in medicinal plant tissue and could produce some secondary metabolites. This research was done to 1) determine the endophytic fungi position in the Hedychium acuminatum Roscoe. plant tissue by histological observation, 2) identify the endophytic fungi species isolated from the rhizome, leaf sheath, and the leaf of H. acuminatum, and 3) analyze the contents of some secondary metabolites that be produced by the endophytic fungi species isolated from H. acuminatum. The determination of the position of endophytic fungi in the H. acuminatum plant tissue was done by histologic observation. The endophytic fungi were isolated from H. acuminatum plant, then were inoculated on Potato Dextrose Agar medium and incubated at 25 °C during 7 to 14 × 24 h. Each endophytic fungus isolate was identified. Each endophytic fungus isolate was inoculated in Potato Dextrose Broth medium and shook at 120 rpm for 7 × 24 h; then the secondary metabolites content was analyzed using the spectrophotometric method. The research result was: 1) the endophytic fungi mycelium were found on the parenchyma cell wall and intercellular space of rhizome, epidermis and parenchyma cell wall of leaf sheath, epidermis cell wall of leaf; 2) eleven endophytic fungi species were found: Rhizoctonia sp., Fusarium solani, F. oxysporum, Colletotrichum alienum, C. aotearoa, C. ti, Aspergillus parasiticus, C. coccodes, C. gloeosporoides, Hansfordia biophila, and F. semitectum; 3) the secondary metabolites content in fungi culture in broth medium are: alkaloid 20.48 µm · mL−1 to 117.12 µm · mL−1), flavonoid (148.48 µm · mL−1 to 816.96 µm · mL−1), terpenoid (4.73 µm · mL−1 to 32.98 µm · mL−1), and tannin (9.39 µm · mL−1 to 53.02 µm · mL−1).