Aflatoxin-producing Aspergillus species from Thailand.

Aflatoxin-producing Aspergillus species were isolated from soil samples from ten different regions within Thailand. Aspergillus flavus was present in all of the soil samples. Unlike previous studies, we found no A.

The aflatoxin biosynthesis cluster gene, aflX, encodes an oxidoreductase involved in conversion of versicolorin A to demethylsterigmatocystin.

Biosynthesis of the toxic and carcinogenic aflatoxins by the fungus Aspergillus flavus is a complicated process involving more that 27 enzymes and regulatory factors encoded by a clustered group of genes. Previous studies found that three enzymes, encoded by verA, ver-1, and aflY, are required for conversion of versicolorin A (VA), to demethylsterigmatocystin. We now show that a fourth enzyme, encoded by the previously uncharacterized gene, aflX (ordB), is also required for this conversion.

Divergent regulation of aflatoxin production at acidic pH by two Aspergillus strains.

Production of aflatoxins (AF) by Aspergillus flavus and A. parasiticus is known to occur only at acidic pH. Although typical A.

An isolate of Aspergillus flavus used to reduce aflatoxin contamination in cottonseed has a defective polyketide synthase gene.

Contamination of certain foods and feeds with the highly toxic and carcinogenic family of Aspergillus mycotoxins, the aflatoxins, can place a severe economic burden on farmers. As one strategy to reduce aflatoxin contamination, the non-aflatoxin-producing A. flavus isolate AF36 is currently being applied to agricultural fields to competitively exclude aflatoxin-producing Aspergillus species.