Abstract
Endophytic microorganisms are the storehouse of novel secondary metabolites that can serve as an excellent source of drugs for different ailment. In this study, we isolated endophytic fungi associated with Azadirachta indica collected from Agulu, Awka, Anambra State, South Eastern Nigeria, identified some of their bioactive secondary metabolites and evaluated their antimicrobial properties. The endophytic fungi were isolated following standard method and the pure culture of the isolates identified morphologically and molecularly. The fungi were subjected to solid-state fermentation on rice medium and the metabolites were extracted using ethyl acetate. The fungal crude extracts were screened for antimicrobial activity. The extracts were further subjected to high-performance liquid chromatography-diode-array detection (HPLC-DAD) analysis for the identification of the bioactive compounds. A total of four endophytic fungi identified as Aureobasidium sp. (AIL1), Sodaria sp. (AIL3), Aspergillus sp. (AIS1) and Penicillium sp. (AIS2) were isolated from the Azadirachta indica. The crude extracts at 1 mg/mL, showed varying degrees of antimicrobial activity against the test fungi and bacteria Iinhibtion zone diameter (IZD) ranged from 2 to 11 mm. The minimum inhibitory concentrations (MICs) of the fungal extracts ranged from 0.0625 to 0.25 mg/mL. The HPLC-DAD analysis revealed the presence Glucobrassicin, Ferulic acid, 4-methoxybenzaldehyde, 12-Hydroxy-16-scalaren, 12-O-deacetyl-12-epi-scalarin, Ixoside, Citreodrimene F, and Cytosporin D, some of which has been reported to have shown antimicrobial activity. Azadirachta indica possess sundry groups of fungal endophytes that contain secondary metabolites with interesting antimicrobial properties that could be explored in drug discovery.
Highlights
Infectious and parasitic diseases account for approximately half of the deaths worldwide [1]
Endophytic microorganisms are the storehouse of novel secondary metabolites that can serve as an excellent source of drugs for different ailment
This study aims at isolating some endophytic fungi from the leaves and stem of A. indica, as well as secondary metabolites of these fungi and investigating the biological potentials of the isolated metabolites
Summary
Infectious and parasitic diseases account for approximately half of the deaths worldwide [1]. Endophytes are an under-investigated group of microorganisms that represent a plentiful and renewable source of bioactive and chemically new compounds with potential for exploitation in a wide variety of medical, agricultural, and industrial realms [5]. The association between fungal endophytes and their host plant is due to the result of unique adaptations which enable the endophytes to harmonize their growth with that of their host [6] They are a taxonomically and ecologically heterogeneous group of organisms; mainly belonging to Ascomycota, coelomycetes, and hyphomycetes [7, 8].Recently, many known, as well as new endophytic bioactive metabolites, possessing a wide variety of biological activities as antibiotic, antiviral, anticancer, anti-inflammatory, antioxidant, etc., have been identified [9,10,11,12,13,14,15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
