Eicosane: An antifungal compound derived from Streptomyces sp. KF15 exhibits inhibitory potential against major phytopathogenic fungi of crops

• Published in: Environmental research 2024-06, Vol.251 (Pt 1), p.118666, Article 118666
• Main Authors: Bhat, Meghashyama Prabhakara, Kumar, Raju Suresh, Chakraborty, Bidhayak, Nagaraja, Shashiraj Kareyellappa, Gireesh Babu, K., Nayaka, Sreenivasa
• Format: Article
• Language: English
• Subjects: Antifungal activity; antifungal agents; antifungal properties; bioactive compounds; chromatography; crop losses; crop production; Eicosane; financial economics; food security; fungi; growth curves; hyphae; mass spectrometry; molecular weight; mycelium; Nuclear magnetic resonance; plant pathogens; Poisoned food method; research and development; staple foods; Streptomyces; Streptomyces sp. KF15; Turbidimetry
• ISSN: 0013-9351; 1096-0953; 1096-0953
• DOI: 10.1016/j.envres.2024.118666

In the present scenario, food security is of major concern due to exponentially increasing population and depleted crop production. The fungal diseases have contributed majorly to the scarcity of staple food products and economic loss worldwide. This problem could be tackled by preventing the crop loss during both pre and post-harvest seasons. During the current investigation, the bioactive compound eicosane was extracted from Streptomyces sp. KF15, subjected to purification and identified based on mass spectrometry and NMR analysis. The evaluation of in-vitro antifungal activity was done by poisoned food method, SEM analysis and growth pattern analysis. The bioactive compound eicosane with molecular weight of 282.5475 g/mol was purified by column chromatography and the straight chain hydrocarbon structure of CH3CH2(18)CH3 was elucidated by NMR analysis. In poisoned food assay, eicosane effectively inhibited the radial growth of all tested fungal pathogens; F. oxysporum was found to be the most sensitive with 24.2%, 33.3%, 42.4%, and 63.6% inhibition at 25–100 μg/ml concentrations. The SEM micrograph established clear differences in the morphology of eicosane treated fungi with damaged hyphae, flaccid mycelium and collapsed spores as compared to the tubular, turgid and entire fungi in control sample. Finally, the growth curve assay depicted the right side shift in the pattern of eicosane treated fungi indicating the delay in adapting to the conditions of growth and multiplication. The findings of this study encourage further research and development towards the novel antifungal drugs that can act against major phytopathogens. •Eicosane with molecular weight of 282.5475 g/mol was identified by GC-MS analysis.•NMR analysis determined the structure of eicosane as a straight chain hydrocarbon.•Eicosane exhibited increased antifungal activity with increase in concentration.•Eicosane treated fungal cells were deformed, collapsed with shrinkage & aplanation.•Eicosane treated fungal cells failed to attain exponential growth in the analysis.