In vitro inhibition of tomato Fusarium wilt causative agent by zearalenone from a soil inhabiting fungus

• Published in: African journal of biotechnology Vol. 11; no. 72; pp. 13683 - 13689
• Main Authors: Njue, A W, Njogu, E M, Otaye, DO, Cheplogoi, P K, Omolo, JO
• Format: Journal Article
• Language: English
• Published: 06-09-2012
• Subjects: Fusarium; Lycopersicon esculentum
• DOI: 10.5897/AJB12.501
• EISSN: 1684-5315

To find naturally occurring compounds for the control of Fusarium wilt disease of tomato in the farming fields, 200 fungal strains were cultured in liquid media and screened for antifungal activity against Fusarium oxysporium f. sp. Lycosperci. The screening was carried out using in vitro antifungal assays and coincidentally a strain of Fusarium species was found to produce secondary metabolites, which were prepared as crude extracts that showed strong antifungal activity. The responsible compound was purified using column chromatography and the chemical structure of the purified compound was determined using nuclear magnetic resonance (NMR) spectroscopic techniques. A known compound, zearalenone, was found to be responsible for the antifungal activity, with a minimum inhibitory concentration (MIC) of 550 plus or minus 10.5 ppm. This is a sufficient inhibition for F. oxysporium f. sp. Lycosperci, which is the causative agent for Fusarium wilt disease to tomato. Given the global abundance of zearalenone and its implication to human health, the results from this study suggest a sustainable manner of disposing of the mycotoxin and simultaneous benefit in control of the Fusarium wilt disease. It is recommended from this finding that it can be used to suppress fungal attack onto the roots of tomato plant to manage the Fusarium wilt disease.