Low-dose ethanol increases aflatoxin production due to the -dependent incorporation of ethanol into aflatoxin biosynthesis.

Aflatoxins are toxic secondary metabolites produced by some aspergilli, including . Recently, ethanol has attracted attention as an agent for the control of aflatoxin contamination. However, as aflatoxin biosynthesis utilizes acetyl coenzyme A, ethanol may be conversely exploited for aflatoxin production. Here, we demonstrated that not only the C of labeled ethanol, but also that of labeled 2-propanol, was incorporated into aflatoxin B and B, and that ethanol and 2-propanol upregulated aflatoxin production at low concentrations (<1% and <0.6%, respectively). In the alcohol dehydrogenase gene deletion mutant, the C incorporation of labeled ethanol, but not labeled 2-propanol, into aflatoxin B and B was attenuated, indicating that the alcohols have different utilization pathways. Our results show that utilizes ethanol and 2-propanol as carbon sources for aflatoxin biosynthesis and that indirectly controls aflatoxin production by balancing ethanol production and catabolism.