Secondary Metabolite Production and Terpenoid Biosynthesis in Endophytic Fungi Cladosporium cladosporioides Isolated from Wild Cymbopogon martinii (Roxb.) Wats

Abstract

Endophytic fungi Cladosporium cladosporioides (F1-MH810309) and Cladosporium tenuissimum (F2-MN715834) from the leaf of wild Cymbopogon martinii (MT90507) were isolated and selected based on the persistent occurrence during different seasons of the year. They were identified based on the morphological features and molecular characterization (ITS sequence), and later deposited at NCBI. Phytochemical studies on F1, F2 and host extracts showed the presence of alkaloids, flavonoids, phenols, terpenoids and tannins. The GC-MS of F1 extract (control) under the axenic condition revealed compounds like hexadecane, heptadecane,2,4-Ditert-butylphenol, E-14 hexadecenal, geraniol, geranyl acetate and cubenol similar to the host. The GC-MS of F2 extract (control) revealed metabolites that were unique. Further, both F1 and F2 were cultured in the supplementation of different concentrations (5%, 10%, 15% and 20%) of the host plant extract (an-axenic condition). The GC-MS of F1 extracts (test) exhibited good growth and showed the gradual increased production of terpenoid compounds whereas the F2 (test) did not show any growth. These compounds such as hyrdoxymenthol, nor-borneol, cedralacetate, α-cyclogeraniol, campesterol, β-cyclogeraniol, linalool oxide,2,3-boranediol, citronellyltiglate and 2,3-pinanediol were produced in a minor quantity and were known as biotransformed forms of the precursor compounds present in the host extract. In comparison, only F1 was able to produce terpenoids similar to the host species both in axenic and an-axenic conditions. Hence from the current study, the endophytic fungus F1 isolated from wild C. martinii for the first time can serve as a better resource for the bioprospection of an important terpenoid and its metabolites.

UV-mediated enhancement of antibacterial secondary metabolites in endophytic Lasiodiplodia theobromae

“…Specifically, 2,4-di-tert-butylphenol is one of the abundant compounds produced by L. theobromae, and its UV-treated mutants, and has been recorded to have several biological activities (Nwobodo et al, 2022). This finding is in agreement with the report of Jayaram et al (2021), that 2,4-di-tert-butylphenol is a major compound produced by different endophytes with several therapeutic applications.…”

“…Peak area is directly proportional to the concentration of the compound present in the solvent. Most of the listed compounds detected from the fungal endophytes in this study have been produced by other species of endophytic fungi in other studies, and observed to have varying biological properties (Guimarães et al, 2019;Jayaram et al, 2021;Khaled et al, 2021). The bulk of the active compounds identified by GC-MS in this study are essential oils, which may contribute to the antibacterial activity shown against pathogenic bacteria that are susceptible to them.…”

Eco-friendly synthesized silver nanoparticles from endophytic fungus Phyllosticta owaniana: KUMBMDBT-32 and evaluation of biomedical properties

“…1 lter paper and the resulting ltrate was extracted with ethyl acetate as the solvent system (1:1). The extract was concentrated under decreased pressure and evaporated to dryness at 40°C using a rotating vacuum evaporator (Jayaram et al 2021).…”