An ITS-RFLP method to identify black Aspergillus isolates responsible for OTA contamination in grapes and wine

Int J Food Microbiol. 2007 Jan 25;113(2):147-53. doi: 10.1016/j.ijfoodmicro.2006.06.023. Epub 2006 Jul 25.

Abstract

Ochratoxigenic mycobiota in grapes from representative wine regions in Valencia was identified. Black aspergilli were predominant among the different Aspergillus spp. isolated. Restriction digestion analysis of the ITS products was tested as a rapid method to identify isolates of black Aspergillus species from grapes. Restriction endonuclease digestion of the ITS products using the endonucleases HhaI, NlaIII and RsaI, distinguished five types of restriction fragment length polymorphism (RFLP) corresponding to Aspergillus niger, Aspergillus tubingensis, Aspergillus carbonarius and Aspergillus aculeatus species. In addition, a new RFLP type in the A. niger aggregate was identified. The fragments obtained by digestion with the endonuclease NlaIII could be used to identify these new isolates. Black Aspergillus isolates were tested for their ability to produce OTA. Most of the isolates that produced ochratoxin A in YES medium belonged to A. carbonarius species. These results support evidence that A. carbonarious greatly contributes to OTA contamination in grapes and consequently in wine. The ITS-RFLP assay is proposed as a rapid and easy method to identify black Aspergillus species isolated from grapes, especially in studies that involve a large number of isolates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspergillus / isolation & purification*
  • Aspergillus / metabolism
  • DNA Restriction Enzymes
  • Food Contamination / analysis*
  • Food Microbiology
  • Ochratoxins / analysis*
  • Ochratoxins / biosynthesis
  • Polymorphism, Restriction Fragment Length
  • Vitis / chemistry*
  • Vitis / microbiology*
  • Wine / analysis
  • Wine / microbiology

Substances

  • Ochratoxins
  • ochratoxin A
  • DNA Restriction Enzymes