Biodegradation Characteristics and Mechanism of Aflatoxin B1 by Bacillus amyloliquefaciens from Enzymatic and Multiomics Perspectives

Aflatoxin B₁ (AFB₁), a mycotoxin and natural carcinogen, commonly contaminates cereals and animal feeds, posing serious health risks to human and animal. In this study, Bacillus amyloliquefaciens ZG08 isolated from kimchi could effectively remove 80.93% of AFB₁ within 72 h at 37 °C and pH 7.0. Metabolome and transcriptome analysis showed that metabolic processes including glycerophospholipid metabolism and amino acid metabolism were most affected in B. amyloliquefaciens ZG08 exposed to AFB₁. The adaptation mechanism likely involved activation of the thioredoxin system to restore intracellular redox equilibrium. The key genes, tpx and gldA, overexpressed in Escherichia coli BL21, achieved degradation rates of 60.15% and 47.16% for 100 μg/kg AFB₁ under optimal conditions of 37 °C and pH 8.0 and 45 °C and pH 7.0, respectively. The degradation products, identified as AFD₁, were less cytotoxic than AFB₁ in HepG2 cells. These findings suggest potential strategies for utilizing probiotics and engineered enzymes in AFB₁ detoxification.