Production of inhibitory extrolites is a shared trait among non-aflatoxigenic Aspergillus flavus

AIMS: Assess the potential for Aspergillus flavus biocontrol isolates from different geographic regions to secrete metabolites with inhibitory properties against mycotoxigenic isolates. METHODS AND RESULTS: Using four Aspergillus isolates from Arizona, Georgia, and Mississippi, mycotoxin producing isolates from each region were grown on media previously colonized by a biocontrol isolate to assess the inhibition potential of biocontrol-produced extrolites. Significant changes in growth and/or mycotoxin production were observed. CONCLUSIONS: Production of inhibitory extrolites is a trait shared by biocontrol isolates. Mycotoxin reduction was not directly proportional to growth for most isolates, since extrolites secreted by the examined biocontrol isolates were able to greatly reduce mycotoxin production even if growth was minimally inhibited. Only the Georgia isolates exhibited a linear relationship between reduced growth and mycotoxin reductions, indicating that their mycotoxin reductions were primarily due to reduced growth.