Abstract

Effects of interacting conditions of sub-lethal levels of antioxidants, water potential ( ) and temperaturewere evaluated on growth, sclerotial characteristics, aflatoxin B1 (AFB1) production and aflD (=nor-1) geneexpression by Aspergillus flavus strain RCP08108. These studies were carried out on peanut meal extractagar osmotically modified to-2.8,-7.1,-9.9 and-16.0 MPa and incubated at 28 and 20 oC. The foodgrade antioxidants added were butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) at(1 + 1 mM-M1) and (5 + 5 mM-M2). To relate the aflD expression after toxigenic A. flavus grew underinteracting stress conditions, real-time PCR was used. Antioxidant mixtures caused a higher and significant(p < 0.001) reduction in growth rate. The major impact on size and volume sclerotia was producedby  ; followed by antioxidant mixtures. High AFB1 levels were observed in response to the M1 appliedat-7.1 MPa. Induction of the aflD gene was observed in response to the M1 treatment at-2.8,-7.1 and-9.9 MPa; but significant decreases of AFB1 production and aflD transcripts were observed; when thefungus grew in the presence of the M2 treatment.These results showed that it is necessary to apply food-grade antioxidants into the peanut storagesystem at levels higher than 5 mM. This is an important tool to avoid sub-lethal antioxidant doses thatcan lead to fungal growth, increase resistance structures, and stimulate aflD gene expression and AFB1accumulation in this substrate.

Autore Pugliese

• Rosso Laura Cristina

Tutti gli autori

• M.A. Passonea; L.C. Rosso; M. Etcheverry

Titolo volume/Rivista

Microbiological research

Anno di pubblicazione

2012

ISSN

0944-5013

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

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Numero di citazioni Scopus

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Settori ERC

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Codici ASJC

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