Studies on Endophytic Fusarium Species Isolated from Medicinal Plants
Eunice Ngozi Anaele*1, 2, Happiness Chiege Ugwoke2
- South-East Zonal Biotechnology Center, University of Nigeria, Nsukka.
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka
| Key words:
Fungal endophyte, Fusarium species, bioactive compound, antimicrobial activity, terpenoid, medicinal plant.
*Corresponding author: eunice.anaele@unn.edu.ng; Page No: 259-269 |
AbstractThe seasonal availability and possible extinction of some medicinal plants necessitated the search for sustainable source of bioactive compounds. The study evaluated the bioactivity potentials of endophytic Fusarium species isolated from two medicinal plants, Senna alata L, and Mitracarpus hirtus L (DC), using in vitro methods. The isolation of Fusarium involved the surface-sterilization of plant leaves followed by inoculation on potato dextrose agar supplemented with 5 mL/L of gentamicin, incubation at 28±2°C for 3–7 days, and fungal identification using standard microbiological methods. Mycelial plug from seven-day old pure culture of endophytic fungi was inoculated into 50 ml potato dextrose broth, incubated for 21 days at 28±2°C for the secondary metabolites production. The resultant broth culture was filtered to obtain a cell-free filtrate. The antimicrobial activity of the filtrate was determined against Escherichia coli, Staphylococcus aureus, Salmonella and Bacillus species using agar-well diffusion technique. Further antimicrobial assay was carried out against S. aureus using broth dilution method by measuring the optical density at one-hour interval. The enzyme activity of the endophytes and the phytochemical analysis of the secondary metabolites were determined. The isolated endophytic fungi from the plants were identified as Fusarium species. The cell-free filtrate (secondary metabolite) inhibited the growth of S. aureus showing its activity within 2-5 h of incubation when compared to the control. Endophytic fungi isolated from M. hirtus produced terpenoid, flavonoid and tannin while isolate from S. alata produced flavonoid and tannin. The production of amylase was significantly high in isolates from Mitracapus (MSW) but moderate in isolates from Senna (CAG), while proteinase was produced in low quantity by both isolates. None of the isolates produced laccase. The study has shown that Fusarium species isolated form S. alata and M. hirtus produced secondary metabolites with potential bioactivities.
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