Abstract
A bacteria capable of degrading aflatoxin M(1) (AFM(1)) was isolated from African elephant manure. It was identified as Bacillus pumilus by 16s rDNA sequencing and named B. pumilusE-1-1-1. Compared with physical and chemical methods, biological methods have attracted much attention due to their advantages, such as thorough detoxification, high specificity, and environmental friendliness. This work aimed to study the effects of a recombinant catalase (rCAT) from B. pumilusE-1-1-1 on the degradation of AFM(1) in pattern solution. The degradation mechanism was further explored and applied to milk and beer. Kinetic Momentum and Virtual Machine Maximum values for rCAT toward AFM(1) were 4.1 μg/mL and 2.5 μg/mL/min, respectively. The rCAT-mediated AFM(1) degradation product was identified as C(15)H(14)O(3). Molecular docking simulations suggested that hydrogen and pi bonds played major roles in the steadiness of AFM(1)-rCAT. In other work, compared with identical density of AFM(1), survival rates of Hep-G2 cells incubated with catalase-produced AFM(1) degradation products increased by about 3 times. In addition, degradation rates in lager beer and milk were 31.3% and 47.2%, respectively. Therefore, CAT may be a prospective substitute to decrease AFM(1) contamination in pattern solution, milk, and beer, thereby minimizing its influence on human health.