Production and partial characterisation of an inducer-dependent novel antifungal compound(s) by Pediococcus acidilactici LAB 5.

Background: Pediococcus acidilactici LAB 5 produces an antifungal compound under in vitro conditions in an inducer-dependent manner. The main objective of the present study was to partially characterise this antifungal compound by UV-visible, IR, (1)H NMR, (13)C NMR and GC/MS analyses and also to assess its potentiality against a number of food spoilage, plant-pathogenic and human-pathogenic fungal species.

Results: The strain produced a broad-spectrum antifungal compound(s) that was induced by certain constituent factors of MRS and malt extract media. The production was higher in solid culture than in broth culture. The product was found to be a mixture of lactic acid and a compound of molecular mass 83. The minimum inhibitory concentrations (MIC90, 1.32-2.86 g L(-1)) of the active extract were much lower than those of sodium benzoate and calcium propionate. Scanning electron micrographs proved its drastic action on the development of conidial structures.

Conclusion: The chemical analysis indicated a novel compound with fungicidal activity. This compound could be used in fermented foods and feeds to extend their shelf life and also in agricultural crop plants against certain fungal pathogens.