Resumo

CASTRILLO, María Lorena; JERKE, Gladis  e  HORIANSKI, Marta Aurelia. Detection of ocratoxin A production by Aspergillus section Nigri strains isolated from composed yerba mate. Rev. Mex. Mic [online]. 2014, vol.40, pp.1-6. ISSN 0187-3180.

Ochratoxin A (OTA) is an teratogenic, immunosuppressor, nefrotoxic and carcinogenic mycotoxin produced by the genus Aspergillus and Penicillium. Recent studies demostrated that Aspergillus section Nigri are important producers of this toxin and are part of micobiota found ¡n several foods. The objective of the present work were to investígate genus Aspergillus incidence in composed yerba mate and to determine ochratoxin A production by Aspergillus section Nigri strains. Were isolated 2072 Aspergillus strains from 41 samples of composed yerba mate, of the total 1635 belonging to Nigri section. For detection ochratoxin A production, the strains were cultivated in Czapeck yeast extract agar, at 25 °C for 7 days and the toxin was detected by thin layer chromatography under UV light. From the 1635 strains we studied, to corresponded 40% to A. japonicus var. japonicus, 28% A. japonicus var. aculeatus, 16% A. niger var. niger, 12% A. foetidus, 2% A. carbonarius and 2% A. niger var. awamori. Less than 1% of the strains showed ochratoxin A production in vitro, being the specie unique OTA production A. japonicus var. aculeatus.

Palavras-chave : Ilex paraguariensis; filamentous fungí; moulds; mycotoxins.