Management of Aflatoxin B1 Producing Aspergillus flavus on Walnuts and Pistachio Seeds.

Aflatoxins are extremely potent natural carcinogens and a major food safety concern because of potential contamination of food commodities. Plant resistance to aflatoxin contamination is not commercially available and fungicides are not effective. The use of antagonists microorganisms against mycotoxin fungi is a promising approach to manage aflatoxin contamination via biological control. The objective of this study was to evaluate some effective biological control include Rhodotorula glutinis, Penicillium oxalicum and Trichoderma harzianum for inhibition aflatoxin B1 produce by Aspergillus flavus isolated from Walnuts and Pistachio grown in Sinai governorate. The filtrates of all isolates produced varying degrees of inhibition against A. flavus. Nevertheless, the highest percentage of inhibition of toxigenic A. flavus by the culture filtrate of R. glutinis at 150 mg/kg . The ability of biological control agents strains to prevent aflatoxin production have been confirmed by HPLC analysis. Certain yeast strain was found to confine the spreading and sporulation and reduce the amount of aflatoxin production. Sporulation was limited due to the inhibitory effect of yeast. There was a noticeable decrease in fungal dry mass and aflatoxin production. Treated walnuts and pistachio and seeds with biocontrol isolates were effective in controlling fungal infection and increased seeds germination . Rhodotorula glutinis and Trichoderma harzianum antagonistic isolates provided good protection against A.