Isolation and screening of endophytic fungi from Eritrean traditional medicinal plant Terminalia brownii leaves for antimicrobial activity

N. Saleem Basha, Azieb Ogbaghebriel, Kflom Yemane, Misgana Zenebe


Plants formed the basis of sophisticated traditional medicine systems that have been in existence for thousands of years. But, the advent of drug resistance in human pathogenic bacteria and others has prompted a search for more and better antibiotics. This has led to the identification of a new promising source of antimicrobials known as endophytes. Hence, our study was aimed to investigate the ability of endophytic fungi isolated from T. brownii to produce secondary metabolites, which can act as antimicrobial agents. In this preliminary investigation, the leaves were used for isolation of endophytic fungi and fermented, and the cell free ferment broth was subjected to antimicrobial screening against six human pathogens; Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli and Candida albicans by using standard protocol of agar well diffusion method. The results of the endophyte isolation gave three fungal isolates named TBF1, TBF2 and TBF3. According to morphological and microscopical characterizations, the isolates were found to be similar to Rhizophus oryzae (TBF1), Aspergillus niger (TBF2) and Aspergillus flavus (TBF3). Two of the three isolated endophytes i.e., TBF2 and TBF3 showed potential antimicrobial activity against S. aureus and no inhibition was found against other tested pathogens. The present study has proven that T. brownii may be a rich source of endophytic
fungi with antimicrobial potential and our findings may form a basis for further studies on endophytic fungi from medicinal plants for antimicrobial activities.
Key words: Agar well diffusion method, antimicrobial activity, endophytic fungi, medicinal plant, Terminalia brownii

Full Text:



Levy SB. Antibiotic resistance-the problem intensifies. Adv Drg

Deliv Rev 2005;57:1446-50.

Balagurunathan R, Radhakrishnan M. Exploiting the less explored‐

Microbial Endophytes. Adv Biotechnol 2007;6:20‐3.

Wilson D. Endophyte: The evolution of a term, and clarification

of its use and definition. Oikos 1995;73:274-6.

Ryan RP, Germaine K, Franks A, Ryan DJ, Dowling DN. Bacterial

endophytes: Recent developments and applications. FEMS

Microbiol Lett 2008;278:1-9.

Strobel G. Harnessing endophytes for industrial microbiology.

Curr Opin Microbiol 2006;9:240-4.

Strobel G, Daisy B. Bioprospecting for microbial endophytes and

their natural products. Microbiol Mol Biol Rev 2003;67:491-502.

Strobel G, Daisy B, Castillo U, Harper J. Natural products from

endophytic microorganisms. J Nat Prod 2004;67:257-68.

Zhang HW, Song YC, Tan RX. Biology and chemistry of

endophytes. Nat Prod Rep 2006;23:753-71.

Schutz B. Endophytic fungi: A source of novel biologically active

secondary metabolites. Swansea: Proceedings of International

Symposium on Bioactive Fungal Metabolites Impact and

Exploitation, British Mycological Society, University of Wales; 2001.

Castillo U, Harper JK, Strobel GA, Sears J, Alesi K, Ford E, et al.

Kakadumycins, novel antibiotics from Streptomyces sp. NRRL

, an endophyte of Grevillea pteridifolia. FEMS Microbiol Lett


Li JY, Harper JK, Grant DM, Tombe BO, Bashyal B, Hess WM,

et al. Ambuic acid, a highly functionalized cyclohexenone with

antifungal activity from Pestalotiopsis spp. and Monochaetia sp.

Phytochemistry 2001;56:463-8.

Lee J, Lobkovsky E, Pliam NB, Strobel GA, Clardy J. Subglutinols A

and B: Immunosuppressive compounds from the endophytic

fungus Fusarium subglutinans. J Org Chem 1995;60:7076-7.

Petrini O. Taxonomy of endophytic fungi of aerial plant tissues. In:

Fokkenna NJ, Van Den HJ, Editors. Microbiology of the phylospere.

Cambridge: Cambridge University Press; 1986. p. 175-87.

Schulz B, Wanke U, Draeger S, Aust HJ. Endophytic from

herbaceous plants and shrubs: Effectiveness of surface sterilization

method. Mycol Res 1993;97:1447-50.

Arunachalam C, Gayathri P. Studies on bioprospecting of

endophytic bacteria from the medicinal plant of Andrographis

paniculata for their antimicrobial activity and antibiotic

susceptibility pattern. Int J Curr Pharm Res 2010;2:63-8.

Ravikumar S, Inbaneson SJ, Uthiraselvam M, Kaleeswari R,

Ramu A, Banerjee MB, et al. Antibacterial activity of heterotrophic

endophytes from Karangkadu Mangrove Ecosystem, India. J

Pharm Res 2011;4:195-8.

Sivakumar K, Sahu MK, Kathiresan K. Isolation and characterizations

of Streptomycetes, producing antibiotic from a mangrove

environment. Asian J Microbiol Biotechnol Environ Sci 2005;7:457-64.

Sutjaritvorakul T, Whalley AJ, Sihanonth P, Roengsumran S.

Antimicrobial activity from endophytic fungi isolated from plant

leaves in Dipterocarpous forest at Viengsa district Nan province,

Thailand. J Agric Tech 2011;7:115-21.

Roy S, Banerjee D. Isolation of antimicrobial compound by

endophytic bacteria from Vinca rosea. Int J Curr Res 2010;5:47-51.

Fiedler HP, Bruntner C, Bull AT, Ward AC, Goodfellow M,

Potterat O, et al. Marine actinomycetes as a source of novel

secondary metabolites. Antonie Van Leeuwenhoek 2005;87:37-42.

Phoebe CH Jr, Combie J, Alert FG, Van Tran K, Cabrera J,

Correira HJ, et al. Extremophilic organisms as an unexplored

source of antifungal compounds. J Antibiot (Tokyo) 2001;54:56-65.

Tan RX, Zou WX. Endophytes: A rich source of functional

metabolites. Nat Prod Rep 2001;18:448-59.

Petrini O. Fungal endophytes of tree leaves. In: Andrews JH,

Hirano SS, editors. Microbial ecology of leaves. New York, USA:

Springer-Verlag; 1991. p. 179-98.

World Health Organization (WHO). In: WHO Traditional Medicine

Strategy 2002-2005. Geneva: WHO; 2002



  • There are currently no refbacks.