Effect of Various Compounds Blocking the Colony Pigmentation on the Aflatoxin B1 Production by Aspergillus flavus

• Main Authors: Vitaly G. Dzhavakhiya, Tatiana M. Voinova, Sofya B. Popletaeva, Natalia V. Statsyuk, Lyudmila A. Limantseva, Larisa A. Shcherbakova
• Format: Article
• Language: English
• Published: MDPI AG 2016-10-01
• Series: Toxins
• Subjects: aflatoxin B1; fungal melanins; polyketide biosynthesis; compactin; thymol; fluconazole; 3-hydroxybenzaldehyde; Aspergillus flavus
• Online Access: http://www.mdpi.com/2072-6651/8/11/313

Aflatoxins and melanins are the products of a polyketide biosynthesis. In this study, the search of potential inhibitors of the aflatoxin B1 (AFB1) biosynthesis was performed among compounds blocking the pigmentation in fungi. Four compounds—three natural (thymol, 3-hydroxybenzaldehyde, compactin) and one synthetic (fluconazole)—were examined for their ability to block the pigmentation and AFB1 production in Aspergillus flavus. All compounds inhibited the mycelium pigmentation of a fungus growing on solid medium. At the same time, thymol, fluconazole, and 3-hydroxybenzaldehyde stimulated AFB1 accumulation in culture broth of A. flavus under submerged fermentation, whereas the addition of 2.5 μg/mL of compactin resulted in a 50× reduction in AFB1 production. Moreover, compactin also suppressed the sporulation of A. flavus on solid medium. In vivo treatment of corn and wheat grain with compactin (50 μg/g of grain) reduced the level of AFB1 accumulation 14 and 15 times, respectively. Further prospects of the compactin study as potential AFB1 inhibitor are discussed.