Prediction and validation of enzymatic degradation of aflatoxin M: Genomics and proteomics analysis of Bacillus pumilus E-1-1-1 enzymes.

Aflatoxins are a class of highly toxic mycotoxins. Aflatoxin M (AFM) is hydroxylated metabolite of aflatoxin B, having comparable toxicity, which is more commonly found in milk. In this study, the whole genome sequencing of Bacillus pumilus E-1-1-1 isolated from feces of 38 kinds of animals, having aflatoxin M degradation ability was conducted. Bacterial genome sequencing indicated that a total of 3445 sequences were finally annotated on 23 different cluster of orthologous groups (COG) categories. Then, the potential AFM degradation proteins were verified by proteomics; the properties of these proteins were further explored, including protein molecular weight, hydrophobicity, secondary structure prediction, and three-dimensional structures. Bacterial genome sequencing combined with proteomics showed that eight genes were the most capable of degrading AFM including three catalases, one superoxide dismutase, and four peroxidases to clone. These eight genes with AFM degrading capacity were successfully expressed. These results indicated that AFM can be degraded by Bacillus pumilus E-1-1-1 protein and the most degrading proteins were oxidoreductases.