Details

Autor(en) / Beteiligte

• Wilkinson, J. R
• Yu, J
• Bland, J. M
• Nierman, W. C
• Bhatnagar, D
• Cleveland, T. E

Titel

Amino acid supplementation reveals differential regulation of aflatoxin biosynthesis in Aspergillus flavus NRRL 3357 and Aspergillus parasiticus SRRC 143

Ist Teil von

• Applied microbiology and biotechnology, 2007-04, Vol.74 (6), p.1308-1319

Ort / Verlag

Berlin: Berlin/Heidelberg : Springer-Verlag

Erscheinungsjahr

2007

Quelle

MEDLINE

Beschreibungen/Notizen

• Aflatoxins are toxic and carcinogenic secondary metabolites produced by the fungi Aspergillus flavus and Aspergillus parasiticus. To better understand the molecular mechanisms that regulate aflatoxin production, the biosynthesis of the toxin in A. flavus and A. parasticus grown in yeast extract sucrose media supplemented with 50 mM tryptophan (Trp) were examined. Aspergillus flavus grown in the presence of 50 mM tryptophan was found to have significantly reduced aflatoxin B₁ and B₂ biosynthesis, while A. parasiticus cultures had significantly increased B₁ and G₁ biosynthesis. Microarray analysis of RNA extracted from fungi grown under these conditions revealed 77 genes that are expressed significantly different between A. flavus and A. parasiticus, including the aflatoxin biosynthetic genes aflD (nor-1), aflE (norA), and aflO (omtB). It is clear that the regulatory mechanisms of aflatoxin biosynthesis in response to Trp in A. flavus and A. parasiticus are different. These candidate genes may serve as regulatory factors of aflatoxin biosynthesis.