Effect of pH on ochratoxin A production by A. niger aggregate species

Grup de Micologia Veterinària, Departament de Sanitat i d'Anatomia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain.
Food Additives and Contaminants (Impact Factor: 2.13). 07/2006; 23(6):616-22. DOI: 10.1080/02652030600599124
Source: PubMed


The effect of pH (2-10) on growth and ochratoxin A (OTA) production by 12 Aspergillus niger aggregate strains was studied in two culture media: Czapek yeast autolysate agar (CYA) and yeast extract sucrose agar (YES), over 30 days. The strains were selected to include different sources, different reported abilities to produce OTA and different ITS-5.8S rDNA RFLP patterns. YES was a better culture medium than CYA for OTA production. In this medium, OTA was produced from pH 2 or 3 to 10 depending on the strain. The results show the ability of A. niger aggregate strains not only to grow, but also to produce OTA over a wide pH range. The results will lead to a better understanding of the role of A. niger aggregate strains in the OTA contamination of several food commodities.

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    • "Recently (Esteban et al., 2006) in an attempt to understand the relative significance of OTA producing fungi showed that A. niger aggregate not only flourishes but also produces OTA over a wide pH range. It may be that the significance of A. niger as an OTA producer has been previously underestimated. "
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