Effects of different substrates and oils on aflatoxin B1 production by Aspergillus parasiticus

Aflatoxin contamination levels vary from crop to crop, suggesting that it is of great significance to explore the effects of different substrates on aflatoxins production. In this study, the effects of corn, wheat, peanut, and soybean on aflatoxin B1 (AFB1) production by Aspergillus parasiticus were investigated, and the effects of corn germ, wheat germ, soybean, and peanut oils on the production of AFB1 by A. parasiticus in the corresponding defatted substrates were evaluated at the rates of 2, 5, 10, and 15 g/100 g of substrate. The effects of the combinations of different oils with different defatted substrates on the accumulation of AFB1 by A. parasiticus were also studied. AFB1 concentration was determined by HPLC. The results indicated that high-lipid substrates of soybean and peanut had significantly higher AFB1 production than low-fat substrates of wheat and corn throughout the entire incubation period (15 days) in both autoclaved and non-autoclaved grains. Corn germ, wheat germ, soybean, and peanut oils with different doses could effectively stimulate AFB1 accumulation, and AFB1 production was determined by the oil content of the substrates. Our results suggest that the oil content of substrates is one of the factors affecting AFB1 production by A. parasiticus and that the composition and content of the substrates may also play a role.