RFLP characterization of Aspergillus niger aggregate species from grapes from Europe and Israel

In order to characterize by molecular methods the Aspergillus niger aggregate species involved in the ochratoxin A (OTA) contamination of European wine grapes and table grapes from Israel, a total of 173 strains were studied. The ITS-5.8S rDNA fragments of 173 A. niger agreggate strains from grapes included in this study were amplified and their PCR amplicons were RsaI digested in order to classify the strains in the RFLP types, N and T. All of the strains belonging to the A. niger aggregate were classified into the two RFLP types previously defined: type N (43%) and type T (57%). Twenty out of the 173 strains of A. niger aggregate produced OTA (0.1 to 10.5 mug g(-1)). All the OTA producing species belonged to the N-RFLP type.