Inhibition of ochratoxin A production in Aspergillus carbonarius by hydroxycinnamic acids from grapes

This study sought to determine the potential of HCAs, such as caffeic, p-coumaric and ferulic acids, as antifungal natural compounds for the control of A. carbonarius growth and OTA production. The HCAs were tested at the increasing concentrations of 0.30, 0.65 and 1.10 mg/ml in minimal medium (MM) and grape juice. Germination of conidia was not affected in neither of the two media in presence of HCAs. At all the concentrations tested, OTA biosynthesis in MM was reduced and the dose effect was more evident for p-coumaric and ferulic acids; in grape juice the reduction trend was confirmed, and ferulic acid showed the highest inhibitory effect. Moreover, the expression level of genes encoding a polyketide synthase (AcOTApks) and a nonribosomal peptide synthetase (AcOTAnrps) involved in OTA biosynthesis, was evaluated by real-time PCR in A. carbonarius grown in presence of 0.65 mg/ml of HCAs. From gene expression analysis only the AcOTApks gene showed a marked reduction of transcription level in presence of p-coumaric and ferulic acids. On the contrary, caffeic acid seemed to not influence the expression levels of the genes analysed in this study, suggesting a different mechanism of action on the regulation of OTA biosynthesis. Content Type Journal ArticleCategory Research-ArticlePages 1-7DOI 10.3920/WMJ2014.1753Authors M. Ferrara, Institute of Sciences of Food Production (ISPA), National Research Council (CNR), Via Amendola 122/O, 70126 Bari, ItalyA. Gallo, ISPA, CNR, via Pr...
Source: World Mycotoxin Journal - Category: Toxicology Tags: World Mycotoxin Journal Source Type: research