Applied Microbiology and Biotechnology

, Volume 76, Issue 5, pp 977–984

Understanding nonaflatoxigenicity of Aspergillus sojae: a windfall of aflatoxin biosynthesis research

  • Perng-Kuang Chang
  • Kenichiro Matsushima
  • Tadashi Takahashi
  • Jiujiang Yu
  • Keietsu Abe
  • Deepak Bhatnagar
  • Gwo-Fang Yuan
  • Yasuji Koyama
  • Thomas E. Cleveland
Mini-Review

Abstract

Aspergillus section Flavi includes aflatoxin-producing and nonproducing fungi. Aspergillus sojae is unable to produce aflatoxins and is generally recognized as safe for food fermentation. However, because of its taxonomical relatedness to aflatoxin-producing Aspergillus parasiticus and A. flavus, it is necessary to decipher the underlying mechanisms for its inability to produce aflatoxins. This review addresses the relationship between A. sojae and A. parasiticus and the advances that have been made in aflatoxin biosynthesis research, especially with regard to gene structure, genome organization, and gene regulation in A. parasiticus and A. flavus and how this has been used to assure the safety of A. sojae as an organism for food fermentation. The lack of aflatoxin-producing ability of A. sojae results primarily from an early termination point mutation in the pathway-specific aflR regulatory gene, which causes the truncation of the transcriptional activation domain of AflR and the abolishment of interaction between AflR and the AflJ co-activator. Both are required for gene expression. In addition, a defect in the polyketide synthase gene also contributes to its nonaflatoxigenicity.

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Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Perng-Kuang Chang
    • 1
  • Kenichiro Matsushima
    • 2
  • Tadashi Takahashi
    • 2
  • Jiujiang Yu
    • 1
  • Keietsu Abe
    • 3
  • Deepak Bhatnagar
    • 1
  • Gwo-Fang Yuan
    • 4
  • Yasuji Koyama
    • 2
  • Thomas E. Cleveland
    • 1
  1. 1.Food and Feed Safety Research Unit, Southern Regional Research Center, Agricultural Research Service, US Department of AgricultureNew OrleansUSA
  2. 2.Noda Institute for Scientific ResearchNoda City, ChibaJapan
  3. 3.Graduate School of Agricultural SciencesTohoku UniversitySendaiJapan
  4. 4.Bioresource Collection and Research CenterFood Industry Research and Development InstituteHsinchuRepublic of China

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