title: Partitioning of ochratoxin A in mycelium and conidia of Aspergillus carbonarius and the impact on toxin contamination of grapes and wine.
abstract: OBJECTIVE
  Aspergillus carbonarius is an important ochratoxin A (OTA)-producing fungus which is responsible for toxin contamination of grapes and wine. The objectives of this study were to examine the partitioning of OTA in mycelium and conidia of a range of A. carbonarius strains on artificial grape juice and defined media, to determine the excretion patterns of OTA from these spores, and the effect of organic acids used in wine production on OTA excretion from conidia.
  
  
  RESULTS
  The results showed that 60-70% of the OTA was accumulated in the conidia of a number of different isolates of A. carbonarius. Calculations showed that on different defined media, an amount of 0.011- to 0.1-pg OTA was present per conidium. The OTA in spores was found to be rapidly excreted into the medium during the initial few hours after conidial germination leading to an increase of OTA in must during maceration for wine production. The presence of tartaric acid inhibited OTA production, but malic acid enhanced this production during mycelial growth. These acids were also shown to affect the time course of germination and the rate of OTA excretion from conidia during germination.
  
  
  CONCLUSIONS
  This study is the first to examine and show the partitioning of OTA into spores of strains of A. carbonarius and that rapid excretion of OTA from spores could be a reason for OTA accumulation in musts during wine production.
  
  
  CONCLUSIONS
  Conidia of A. carbonarius could be a major source of OTA contamination of grapes used in wine production. This information could help in the development of effective prevention strategies to minimize wine contamination with this important mycotoxin.
authors: Département Bioprocédés et Systèmes Microbiens, Laboratoire de Génie Chimique UMR5503 (CNRS/INPT/UPS), Ecole Nationale Supérieure Agronomique de Toulouse, Institut National Polytechnique de Toulouse, Castanet Tolosan, France.
authors: A
authors: A
authors: Atoui
authors: D
authors: D
authors: Mitchell
authors: F
authors: F
authors: Mathieu
authors: N
authors: N
authors: Magan
authors: A
authors: A
authors: Lebrihi
mesh_terms: D001230:Aspergillus / Q000737:chemistry* / Q000187:drug effects / Q000502:physiology; D018533:Biomass; D003470:Culture Media / Q000737:chemistry; D005516:Food Microbiology; D018525:Germination; D006801:Humans; D008293:Malates / Q000494:pharmacology; D025282:Mycelium / Q000737:chemistry; D009793:Ochratoxins / Q000032:analysis* / Q000096:biosynthesis; D013172:Spores, Fungal / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D013644:Tartrates / Q000494:pharmacology; D027843:Vitis / Q000737:chemistry*; D014920:Wine / Q000032:analysis
chemical_list: D003470:Culture Media; D008293:Malates; D009793:Ochratoxins; D013644:Tartrates; C025589:ochratoxin A; C030298:malic acid; C029768:tartaric acid