ABSTRACT
Aspergillus strains belonging to the Aspergillus niger aggregate, either isolated from Italian grapes or received from public collections, were analysed in order to discriminate between the ochratoxin A (OTA) producing and the non-producing strains by means of the analysis of Internal Transcribed Spacers (ITS), Intergenic Spacers (IGS) and of a beta-tubulin gene portion. A. niger and Aspergillus awamori were identified observing the macro- and microscopic features of the colonies and the strains ochratoxigenicity was evaluated through Thin Layer Chromatography and/or High Performance Liquid Chromatography. PCR amplification of ITS, IGS and beta-tubulin gene portion produced 600, 440 and 550 bp amplicons, respectively, in all the analysed strains. The digestion of the IGS amplicon with Hinf I and of the other two amplicons with Rsa I, revealed one main profile type ("T-C-C") associated with the A. niger aggregate strains which lack the ability to produce OTA.
