Screening and identification of an aflatoxin B1-degrading strain from the Qinghai-Tibet Plateau and biodegradation products analysis.

This research aimed to address the issue of aflatoxin B₁ (AFB₁) contamination, which posed severe health and economic consequences. This study involved exploring unique species resources in the Qinghai-Tibet Plateau, screening strains capable of degrading AFB₁. UPLC-Q-Orbitrap HRMS and NMR were employed to examine the degradation process and identify the structure of the degradation products. Results showed that Bacillus amyloliquefaciens YUAD7, isolated from yak dung in the Qinghai-Tibet Plateau, removed 91.7% of AFB₁ from TSB-AFB₁ medium with an AFB₁ concentration of 10 µg/mL (72 h, 37°C, pH 6.8) and over 85% of AFB₁ from real food samples at 10 µg/g (72 h, 37°C), exhibiting strong AFB₁ degradation activity. Bacillus amyloliquefaciens YUAD7's extracellular secretions played a major role in AFB₁ degradation mediated and could still degrade AFB₁ by 43.16% after boiling for 20 min. Moreover, B. amyloliquefaciens YUAD7 demonstrated the capability to decompose AFB₁ through processes such as hydrogenation, enzyme modification, and the elimination of the-CO group, resulting in the formation of smaller non-toxic molecules. Identified products include C₁₂H₁₄O₄, C₅H₁₂N₂O₂, C₁₀H₁₄O₂, C₄H₁₂N₂O, with a structure consisting of dimethoxyphenyl and enoic acid, dimethyl-amino and ethyl carbamate, polyunsaturated fatty acid, and aminomethyl. The results indicated that B. amyloliquefaciens YUAD7 could be a potentially valuable strain for industrial-scale biodegradation of AFB₁ and providing technical support and new perspectives for research on biodegradation products. [ABSTRACT FROM AUTHOR]