Production of aflatoxins by strains of the Aspergillus flavus group maintained in ATCC.

A total of 169 strains of the Aspergillus reference cultures in the Aspergillus flavus group maintained in the American Type Culture Collection (ATCC) were studied for their aflatoxin-producing abilities in rice, peanut and semisynthetic medium, utilizing high pressure liquid chromatography. Fifty-nine of the strains examined were positive for aflatoxin formation. No strains of the food fungi A. oryzae or A. sojae produced detectable levels of aflatoxins, while 33-85% of the strains of A. flavus and A. parasiticus were toxigenic.