In vitro characterization of Bacillus sp. LS100 for detoxifying deoxynivalenol

The mycotoxin deoxynivalenol (DON) contamination in animal feed has been reported to reduce the growth performance of animals and compromise their immune system, especially pigs. Bacterial detoxification is considered a promising strategy to mitigate its harmful effects. We previously identified a bacterial isolate (Bacillus sp. LS100) from the chicken gut with the ability to detoxify DON. To explore its potential application in swine production, the current study was focused on in vitro characterization of Bacillus sp. LS100 with regard to its capacity to detoxify DON. The bacterium was stable in keeping its activity to fully detoxify DON when subcultured for 12 passages under anaerobic conditions. The bacterial culture was successfully scaled up and stored for at least 1 month without losing any activity to detoxify DON. In addition, it was able to fully detoxify DON in mouldy corn with a diluted medium in an anaerobic atmosphere. While the bacterium exhibited a certain degree of tolerance to oxygen, it was sensitive to low pH and bile salts, including pig gastric fluid. In the presence of digesta from the pig jejunum or ileum, the bacteria retained near-full or full detoxification activity of DON after 24 or 48 h incubation under anaerobic conditions. To protect Bacillus sp. LS100 from the detrimental effects of gastric acid and bile salt, the bacterium was encapsulated anaerobically. The encapsulated bacteria stored in wet beads at 22 °C exhibited greater stability and retained detoxification activity longer than those stored in dry beads. After exposure to simulated gastric fluid for 2 h, the bacterium in the wet beads retained the DON detoxification activity. The current study suggests that, when adequately protected, Bacillus sp. LS100 holds promise as a viable strategy for DON removal in the pig gut.