Background and Aim:Toxigenic fungi are among the most important contaminants of food and agricultural products, causing spoilage, economic losses, and serious health problems due to the production of mycotoxins. The search for safe, effective, and natural antifungal alternatives has therefore become an important research priority. In this context, microbial metabolites are considered promising bioactive compounds for controlling fungal growth and reducing toxin contamination. The present study aimed to investigate the inhibitory effect of fatty acids produced by Yarrowia lipolytica on the growth of Aspergillus flavus and Fusarium graminearum.
Material and methods: For this purpose, the target fungal strains were cultured under laboratory conditions, and Y. lipolytica was grown on sweet almond, bitter almond, and castor bean pomace substrates to produce fatty acids, mainly stearic and oleic acids. The produced fatty acids were extracted and quantified using gas chromatography-mass spectrometry (GC-MS). Fungal growth was assessed by spore counting and optical density measurement under different treatment conditions. In addition, the effects of the fatty acids on aflatoxin B1 and zearalenone production were analyzed by high-performance liquid chromatography (HPLC). Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were also determined using serial concentrations of standard and extracted fatty acids.
Results:The results demonstrated that Y. lipolytica was capable of producing both stearic and oleic acids in the tested substrates. Increasing concentrations of these fatty acids significantly reduced fungal growth and suppressed toxin production in a concentration-dependent manner. A. flavus growth was inhibited at 8% (v/v) of the combined fatty acids, whereas F. graminearum was inhibited at 4% (v/v). Moreover, at higher concentrations, namely 16% (v/v) for A. flavus and 8% (v/v) for F. graminearum, complete fungal death was observed, along with total inhibition of aflatoxin B1 and zearalenone production.
Conclusion:These findings indicate that fatty acids produced by Y. lipolytica may serve as effective, natural, and cost-efficient antifungal agents for controlling toxigenic fungi and reducing mycotoxin contamination in food and agricultural systems.