Mechanistic Insights into Aflatoxin B1 and M1 Degradation by Bacillus subtilis HNGD-Mq02 from Wheat Koji and Its Application in Food Detoxification

Aflatoxin B₁ (AFB₁), the most toxic and prevalent mycotoxin in food and feed, and its hydroxylated metabolite aflatoxin M₁ (AFM₁), common in dairy products, pose serious health risks. Effective degradation of these toxins is thus a key goal in food safety. In this study, Bacillus subtilis HNGD-Mq02 was isolated and assessed for its ability to degrade AFB₁ and AFM₁. Under optimal conditions (50 °C, pH 7), the fermentation broth achieved 94.06 and 98.26% degradation, respectively. Ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC-MS) analysis confirmed that both mycotoxins were converted into less-toxic compounds. Zebrafish assays and Ames tests further verified the reduced toxicity of the degradation products. In practical application, the strain reduced AFB₁ by 72.90% in corn flour and AFM₁ by 42.25% in milk powder. Fermentation also led to partial improvements in nutritional quality. These results highlight the potential of B. subtilis HNGD-Mq02 for enhancing the safety and value of food and feed products.