Nitrogen aflatoxin production

EHRLICH, K.C., COTTY, P.J., Variability in nitrogen regulation of aflatoxin production by Aspergillus flavus strains, Appl. Microbiol. Biotechnol., 2002, 60, 174-178. 

Dichlorvos possesses a strong inhibitory effect on aflatoxin biosynthesis in A.flavus and A. parasiticus, presumably by specific enzyme inhibition. Dichlorvos inhibited 90% of the aflatoxin production by A. parasiticus ATCC 15517 (Hsieh, 1973). An early step in the secondary metabolic pathway was inhibited, as only additions of dichlorvos prior to the initiation of toxin production, which occurs 40 hr after incubation effectively stopped the toxin synthesis. The reduction in aflatoxin synthesis was accompanied by the excretion of versiconal acetate (19). Yao and Hsieh (1974) reported the efficient conversion of versiconal acetate (13.7%) into aflatoxin Bj by a nitrogen-free resting cell medium oiA. parasiticus. Averufin is converted into versiconal acetate, and not into aflatoxin Bj, in the presence of dichlorvos (Yao and Hsieh, 1974). 

Table VI. Influence of Nitrogen Source on Growth and Production of Aflatoxin by Aspergillus flavus in a Chemically Defined Medium...

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