Biological Decontamination of Mycotoxigenic Fusarium verticillioides Using Lactiplantibacillus plantarum MYSN128 Isolated from Traditional Vellappam: Implications for Food Safety and Global Mycotoxin Management.

Fungal deterioration of food and feed commodities by mycotoxigenic fungi has become a significant complication worldwide. Fusarium contamination produces extremely noxious mycotoxins such as Fumonisin B1 (FB1) and Fumonisin B2 (FB2), which affect human and animal well-being. The present work explored the fungicidal activities of probiotic bacteria isolated from the traditional fermented food Vellappam. About 20 isolates were obtained from the sample and subjected to initial screening against Fusarium verticillioides. Out of 20, Lactiplantibacillus plantarum MYSN128 exhibited potent antifungal activity against F. verticillioides. Moreover, the isolate MYSN128 was found to survive in acidic and bile environments, but it was susceptible to the tested antibiotics. The isolate displayed 61% autoaggregation, 59.52% cell surface hydrophobicity, and chicken crop epithelial cell adherence. L. plantarum MYSN128 and its CFS affected the growth of conidia, resulting in deformed and damaged conidia. A cell-free supernatant (CFS) at a 20% concentration efficiently reduced mycelial biomass to 0.269 ± 0.11 g, compared to the control at 1.938 ± 0.15 g. Similarly, conidial germination was repressed to 19.12% ± 1.15, and a reduction in F. verticillioides growth was observed on maize seeds treated with CFS after 7 days of incubation. The internal transcribed spacer (ITS) copy number of F. verticillioides declined to 5.23 × 10⁷ and 8.026 × 10⁷ in the presence of L. plantarum MYSN128 and its CFS, respectively, in comparison to 8.940 × 10¹⁰ copies in the control. The damaged and dead spores were stained with propidium iodide, which resulted in a reduction in the live population of F. verticillioides observed after treatment with CFS of MYSN128 in flow cytometric analysis. The isolate was also effective in reducing poultry feed contamination. Hence, our results suggest that L. plantarum MYSN128 possesses capable probiotic characteristics and exhibits prominent antifungal activity, which can be utilized as a preservative for food and feed.