Quantitative antifungal activity of reuterin against food isolates of yeasts and moulds and its potential application in yogurt

Reuterin was produced by L. reuteri ATCC 53608 in MRS and glycerol solution then purified before using. Our data showed that purified reuterin inhibited the growth of tested microorganisms at a concentration of 11 mM or less. Moreover, reuterin showed a fungicidal activity (killed 99.9% of all tested microorganisms) at concentrations equal or below 15.6 mM as indicated by MFC. Values of MFC were comprised between 1.0 and 4.8 of the MIC values, suggesting a potent fungicidal mechanism on both yeasts and filamentous moulds with one exception only. In yogurt, reuterin showed a fungistatic effect at a concentration of 1.38 mM while a fungicidal effect was obtained at 6.9 mM. Therefore, reuterin has a high potential as a food preservative, particularly owing to its biochemical properties and antibacterial and antifungal activities.