Evaluation of the aflatoxin biosynthetic genes for identification of the Aspergillus section Flavi.

Several fungi in the Aspergillus section Flavi have been widely used for fermentative food production, while some related species in the section are known to produce mycotoxin(s) that causes mycotic diseases. Common evolutionary markers, such as rRNA gene sequences and their internal transcribed spacers, cannot differentiate these non-aflatoxin-producing species from aflatoxin producers. Multilocus sequence analysis (MLSA) based on four aflatoxin biosynthetic genes encoding aflR, aflT, norA, and vbs, which are more variable nucleotide sequences than rRNA genes, can distinguish safe koji molds, A. oryzae and A. sojae, from aflatoxin-producing strains, A. flavus, A. toxicarius and A. parasiticus.