Detoxification of deoxynivalenol by Bacillus subtilis ASAG 216 and characterization the degradation process

Deoxynivalenol (DON) is a widely distributed mycotoxin that frequently occurs in various foodstuffs, and poses a health risk to human and animals. Biodegradation of DON to less- or non-toxic substances using naturally existing microorganisms is considered the best approach for DON detoxification. Although various microorganisms capable of detoxifying DON have been reported; however, such studies on probiotic strains are scarce. In this study, a bacterial strain (ASAG 216) showed to possess the capability of detoxifying 100 μg/mL DON by 81.1% within 8 h was isolated from the intestine of a donkey. After morphological observation and 16S rDNA sequence analysis, the strain was identified as Bacillus subtilis. The DON-degradation potential of B. subtilis ASAG 216 was predominantly attributed to the culture supernatant, which turned to be sensitive to heat, sodium dodecyl sulfate, and proteinase K treatment, indicating the possible presence of extracellular proteins or enzymes in the supernatant which were responsible for DON degradation. Moreover, B. subtilis ASAG 216 has a broad temperature (35–50 °C) and pH (6.5–9.0) tolerance on DON degradation, apart from its ability to withstand conditions which generally prevail during the intestinal transit. In addition, the tested strain showed antimicrobial activity against Escherichia coli, Staphylococcus aureus and Salmonella typhimurium. These results provide satisfactory grounds for the potential use of B. subtilis ASAG 216 as a new feed additive to address DON contamination.