Antibacterial activity of endophytic fungi isolated from Sceletium tortuosum L. (Kougoed)
Endophytic fungi have the ability to co-exist with their host plants without causing any harm and are beneficial to both the plant and the fungi. The current study determined the antimicrobial properties and identify the chemical compounds of secondary metabolites produced by endophytic fungi isolated from Sceletium tortuosum L. A total of 60 endophytic fungi produced secondary metabolites that were detected after fermentation and extraction. Antibacterial properties of the secondary metabolites were determined using the disc diffusion assay against pathogenic environmental Gram-positive and Gram-negative bacteria as well as control stains. The chemical compounds were characterized by GC-MS. Overall, 15% of fungal extracts displayed narrow spectrum of activity against the bacteria strains. Despite this, none of the fungal extracts inhibited growth of Enterococcus faecalis (ATCC S1299) and Enterococcus gallinarum (ATCC 700425) while Bacillus cereus (ATCC 10876) was the most susceptible against the fungal extracts. Fusarium oxysporum (GG 008) with accession no. KJ774041.1 displayed significant antibacterial activity that was linked to high levels of 5-hydroxymethylfurfural (HMF) and octadecanoic acid as revealed by GC-MS. This study revealed the presence of bioactive secondary metabolites with antibacterial activities from fungi isolated from Sceletium tortuosum L.
KeywordsEndophytic fungi Sceletium tortuosum Secondary metabolites Bioactive compounds GC-MS analysis Fusarium oxysporum
We would like to express our sincere gratitude to North-West University Postgraduate Merit Bursary and the National Research Foundation (Grant UID No: 105510) for the financial support.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Research involving human participants and/or animals
Not applicable (N/A).
Not applicable (N/A). This research does not involve human participants and/or animals; therefore, no informed consent is needed.
- Alpert PT (2017) Superbugs: antibiotic resistance is becoming a major public health concern. HHCMP 29:130–133Google Scholar
- De Melo FC, De Souzaa RF, Coutinhob PLA, De Souza MO (2014) Synthesis of 5-hydroxymethylfurfural from dehydration of fructose and glucose using ionic liquids. J Braz Chem Soc 25:12Google Scholar
- Ekor M (2013) The growing use of herbal medicines: issues relating to adverse reactions and challenges in monitoring safety. Front Pharmacol 4:1–10Google Scholar
- Fareed S, Jadoon UN, Ullah I, Jadoon MA, Rehman MU, Bibi Z, Waqas M (2017) Isolation and biological evaluation of endophytic fungus from Ziziphus nummularia. J Entomol Zool Stud 5:32–38Google Scholar
- Morris AK, Masterton RG (2002) Antibiotic resistance surveillance: action for international studies. J Antimicrob Chemother 49:7–10Google Scholar
- Musavi SF, Balakrishnan RM (2014) A study on the antimicrobial potentials of an endophytic fungus Fusarium oxysporum NFX 06. J Med Biol Eng 3:162–166Google Scholar
- National Institute of Standards and Technology (NIST) (2018) Chemistry WebBook, SRD 69. https://webbook.nist.gov/cgi/cbook.cgi?ID=57-11-4. Accessed 13 June 2018
- Rai M, Agarkar G, Rathod D (2014) Multiple applications of endophytic colletotrichum species occurring in medicinal plants. Novel plant bioresources: applications in food, medicine and Cosmetics, p 18Google Scholar
- Sharma D, Pramanik A, Agrawal PK (2016) Evaluation of bioactive secondary metabolites from endophytic fungus Pestalotiopsis neglecta BAB-5510 isolated from leaves of Cupressus torulosa D.Don. Biotech 6:1–14Google Scholar
- Sharma A, Kumar V, Kanwar MK, Thukral AK, Bhardwaj R (2017) Phytochemical profiling of the leaves of Brassica juncea L. using GC-MS. Int Food Res J 4:547–551Google Scholar
- Wang JW, Zheng LP, Tan RX (2004) Stimulation of artemisinin production in Artemisia annua hairy roots by the elicitor from the endophytic Colletotrichum sp. Biotechnol Lett 23: 857–860Google Scholar
- World Health Organization WHO (2004) Guidelines on safety monitoring of herbal medicines in pharmacovigilance systems. Switzerland, GenevaGoogle Scholar