Inhibition of some mycotoxigenic fungi by iturin A, a peptidolipid produced by Bacillus subtilis.

Bacillus subtilis produces peptidolipid compounds of the iturin group that have been shown to have antifungal properties, but not all fungal species are sensitive to these compounds. In this study, the activity of iturin A, produced by B. subtilis strain B-3, was tested. Paper disks impregnated with various concentrations of iturin A were placed on agar plates seeded with conidia of toxigenic species of Fusarium, Gerlacia, Penicillium or Aspergillus. Most isolates were inhibited at iturin A concentrations as low as 4 micrograms/disk. Penicillium italicum, P. viridicatum, A. ochraceus and A. versicolor were most strongly inhibited by the iturin whereas P. citrinum and A. parasiticus were least sensitive to iturin A.