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.

Download full-text


Available from: F. Javier Cabañes
  • Source
    • "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. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Fifty individual figs which had been rejected as potentially contaminated by sorting under UV light were separately analysed to identify the presence of fungi and their mycotoxins. Aflatoxin B-1 was found in 49 samples with levels ranging from 0.7 to 222 ng g(-1), with 40 individual figs containing more than 2 ng g(-1), indicating the efficacy of the UV screening process in identifying contaminated fruit. Ochratoxin A (OTA) was found in 32 of the figs at levels from 0.4 to 1710 ng g(-1), with 50% of the samples containing levels above 1 ng g(-1). There was no evident correlation between levels of aflatoxin B-1 and levels of OTA. Twenty fungal species were isolated from the outer and inner surfaces of the figs, some of which were subsequently cultured on YES and PDB and the media analysed for the presence of aflatoxin B-1 and OTA to establish their toxigenicity.
    Full-text · Article · Feb 2008 · World Mycotoxin Journal
  • Source

    Preview · Article ·
  • [Show abstract] [Hide abstract]
    ABSTRACT: The first and second editions of Fungi and Food Spoilage established a reputation as the foremost book on foodborne fungi. This completely revised and updated third edition is an invaluable reference for food microbiologists investigating fungal spoilage and sources of mycotoxin contamination in foods. The introductory chapters of the book deal with the ecology of food spoilage and give an overview of how food processing, packaging and storage affect fungal growth. Subsequent chapters cover the fundamentals of classifying and naming fungi and current methods for isolation and enumeration, including general and special purpose media, incubation conditions, etc. The major part of the book provides keys, descriptions and illustrations of all yeasts and moulds commonly encountered in foods. Characteristics of the species, including their ecology and potential for mycotoxin production, are also included. The broad and practical nature of the coverage will appeal to microbiologists, mycologists and biotechnologists in the food industry, academic, research and public health institutions. Dr John Pitt and Dr Ailsa Hocking are both Honorary Research Fellows at CSIRO Food Science Australia, North Ryde, NSW, Australia. © Springer Science+Business Media, LLC 2009. All rights reserved.
    No preview · Book · Jan 2009
Show more