Evaluation of biological control agents for reduction of aflatoxin contamination in corn using biodegradable corn starch-based bioplastic formulations
Hamed Abbas: USDA ARS BCPRU
<div><em>Aspergillus</em> species produce potent carcinogenic mycotoxins, aflatoxins, which contaminate maize and other crops, resulting in millions of dollars in annual agronomic losses. Biocontrol using competitive displacement of aflatoxigenic <em>Aspergillus flavus</em> by non-aflatoxigenic <em>A. flavus</em> strains such as K49 and Afla-guard<sup>®</sup> was an effective method for reducing aflatoxin contamination of maize in field studies conducted in the Mississippi Delta during the past decade. Current research is focused on improving delivery systems for these biocontrol agents. We have developed and evaluated under field conditions in Italy and USA three formulations of a biodegradable corn starch-based bioplastic that improve the effectiveness of the biocontrol agents in reducing aflatoxin contamination in corn. First, applying bioplastic granules inoculated with <em>A. flavus </em>K49 and/or Afla-guard to field soil reduced aflatoxin contamination up to 90%. Second, spraying a liquid formulation to leaves, which results in the colonization of leaf surfaces with biocontrol <em>A. flavus</em> strains, reduced aflatoxin contamination in corn by 80% to 94%. Third, film-coating seeds with bioplastic containing spores of biocontrol <em>A. flavus</em> strains before planting reduced aflatoxin contamination up to 85%. These results suggest that applying biocontrol <em>A. flavus</em> strains in such bioplastic formulations may be useful for reducing aflatoxin contamination in corn, but additional research is needed to optimize conditions.</div>
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