Targeting a polyketide synthase gene for Aspergillus carbonarius quantification and ochratoxin A assessment in grapes using real-time PCR

Int J Food Microbiol. 2007 Apr 20;115(3):313-8. doi: 10.1016/j.ijfoodmicro.2006.11.006. Epub 2007 Jan 13.

Abstract

Aspergillus carbonarius is an ochratoxin producing fungus that has been considered to be responsible of the ochratoxin A (OTA) contamination in grapes and wine. In order to monitor and quantify A. carbonarius, a specific primer pair Ac12RL_OTAF/Ac12RL_OTAR has been designed from the acyltransferase (AT) domain of the polyketide synthase sequence Ac12RL3 to amplify 141 bp PCR product. Among the mycotoxigenic fungi tested, only A. carbonarius gave a positive result. This specific primer pair was also successfully employed in real-time PCR conjugated with SYBR Green I dye for the direct quantification of this fungus in grape samples. A positive correlation (R(2)=0.81) was found between A. carbonarius DNA content and OTA concentration in 72 grape samples, allowing for the estimation of the potential risk from OTA contamination. Consequently, this work offers a quick alternative to conventional methods of OTA quantification and mycological detection and quantification of A. carbonarius in grapes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspergillus / enzymology*
  • Consumer Product Safety
  • DNA Primers
  • DNA, Fungal / analysis*
  • Food Contamination / analysis
  • Food Microbiology
  • Gene Amplification
  • Ochratoxins / biosynthesis*
  • Polyketide Synthases / genetics*
  • Polymerase Chain Reaction / methods
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Vitis / microbiology*

Substances

  • DNA Primers
  • DNA, Fungal
  • Ochratoxins
  • ochratoxin A
  • Polyketide Synthases