Inhibition of Species of the Aspergillus Section Nigri and Ochratoxin A Production in Grapes by Fusapyrone

Fusapyrone (FP), an antifungal natural compound, was tested against the three main ochratoxigenic species of theAspergillus sectionNigri . The MICs at 24 h were 6.0, 11.6, and 9.9 μg/ml forAspergillus carbonarius ,Aspergillus tubingensis , andAspergillus niger , respectively. Strong inhibition of growth and morphological changes were still observed at half the MIC after 7 days. The application of a 100 μg/ml FP solution in a laboratory assay on artificially inoculated grapes resulted in a significant reduction (up to 6 orders of magnitude) ofA. carbonarius CFU counts. Dramatic reductions of the ochratoxin A (OTA) content, compared to the content of the positive control (average amount of OTA, 112.5 ng/g of grape; three experiments), were obtained with the application of either 100 or 50 μg/ml of FP (0.6 or 5.1 ng/g of grape, respectively).