title: Growth and ochratoxin A production by Aspergillus carbonarius at different pHs and grape maturation stages.
abstract: OBJECTIVE
  The objective of this work was to study the effect of some factors, linked to grape composition during ripeness process, on the growth and ochratoxin A (OTA) production of Aspergillus carbonarius isolated from grapes.
  
  
  RESULTS
  Aspergillus carbonarius isolates were tested (i) in vitro, in Czapek yeast autolysate agar (CYA) at different pHs (2·5-4·5) and incubation times (2-6 days), and (ii) in situ, in fresh grapes collected at different maturation stages. Aspergillus carbonarius was able to grow with the same intensity at the different maturation stages and pH levels tested. In general, a similar trend of OTA production by A. carbonarius in response to acidity in media and in grape was observed. Low pH level seemed optimal for maximum OTA production.
  
  
  CONCLUSIONS
  Aspergillus carbonarius strains can strongly grow and produce OTA on grape from the early stages of maturation. Extrinsic environmental conditions at the harvest period and skin thickness are, probably, the mains factors contributing to OTA contamination of grapes at the end of maturation.
  
  
  CONCLUSIONS
  The results lead to a better understanding of the critical point during grape maturation for the growth of ochratoxigenic fungi and the toxin production.
authors.affiliation: Laboratory of Molecular Physiology of Plants, Borj-Cedria Biotechnology Center, Hammam-Lif, Tunisia. ls_salma@yahoo.fr
authors.forename: S
authors.initials: S
authors.lastname: Lasram
authors.forename: A
authors.initials: A
authors.lastname: Barketi
authors.forename: A
authors.initials: A
authors.lastname: Mliki
authors.forename: A
authors.initials: A
authors.lastname: Ghorbel
mesh_terms: D001230:Aspergillus / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D003470:Culture Media / Q000737:chemistry; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D009793:Ochratoxins / Q000378:metabolism*; D027843:Vitis / Q000254:growth & development / Q000382:microbiology*
chemical_list: D003470:Culture Media; D009793:Ochratoxins; C025589:ochratoxin A