New genotypes of aflatoxigenic fungi from Egypt and the Philippines

Abstract

<p>Aflatoxins (AFs), mainly produced by Aspergillus section Flavi, are the major natural toxins of crops and commodities in hot climatic geographic regions. These toxins are considered as type A carcinogens. One hundred and sixty single spore isolates of A. section Flavi were isolated from two different geographical places, Egypt and the Philippines. A quarter (26.5%) of the isolates was able to produce AFs. Four chemotypes of aflatoxin-producing fungi were obtained. Surprisingly, all aflatoxin-producing A. nomius isolates produced higher amounts (2400-40400 ng ml-1) of total AFs (AFB1, AFB2, AFG1 and AFG2) than the toxigenic A. flavus isolates (<1200 ng ml-1). All isolates producing AFs gave PCR products with the ver-1/ver-2 and ordAF/ordAR primers, which amplify ver-1 and ordA genes in the aflatoxin biosynthetic pathway. Based on PCR products of ver-1 gene, new genotypes of aflatoxigenic fungi were found which revealed the variability of AFs production between different isolates depending on the region of the isolation.<br /></p>