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ARS Home » Southeast Area » Stoneville, Mississippi » Biological Control of Pests Research » Research » Publications at this Location » Publication #305330

Title: Blocking aflatoxins in corn by using non-toxigenic strains of Aspergillus flavus

item Abbas, Hamed

Submitted to: Corn Dry Milling Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/21/2014
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: There are over 500 previously reported mycotoxins. However, only a few have been identified as important for food safety, including aflatoxins, fumonisins, cyclopiazonic acid (CPA), trichothecenes, zearalenone, ochratoxins, and patulin. Mycotoxins contaminate plant materials, causing acute and chronic illnesses in livestock and humans, including teratogensis, carcinogenesis, endocrine disruption and immunosuppression. Aflatoxins are a group of chemical compounds produced by Aspergillus flavus, A. parasiticus, and A. nomius and they are of the greatest concern for food safety, especially in the South. Aflatoxins cause harm to human and animal health including liver cancer. There are not many strategies available to reduce aflatoxins pre-harvest. The best strategy we have found is competitive inhibition by non-toxigenic strains of Aspergillus flavus. There are 3 major strains of A. flavus, Afla-Guard (NRRL 21882), K49 (NRRL 18543), and AF36 (NRRL 30797) that were developed by USDA-ARS researchers and successfully commercialized for several commodities. NRRL 21882 was made commercially available in corn in 2009 as Afla-Guard. Our studies have shown that Afla-Guard and K49 are superior in aflatoxin reduction as compared to AF-36 and also they do not produce CPA. We also have developed delivery formulations to assist in optimizing aflatoxin reduction. Results have been somewhat sporadic in the field. Specific genetic markers (SGMs) have been developed to track A. flavus in the field. SGMs are essential to understand host and biocontrol interactions in order to improve consistency and efficacy of non-toxigenic A. flavus in commercial grower applications.