Biological Degradation of Aflatoxin B1 by Cell-Free Extracts of Bacillus velezensis DY3108 with Broad PH Stability and Excellent Thermostability

(1) Background: Aflatoxin contamination in food and grain poses serious problems both for economic development and public health protection, thus leading to a focus on an effective approach to control it; (2) Methods: Aflatoxin B-1 (AFB(1)) degrading bacteria were isolated using a medium containing coumarin as the sole carbon source, and the biodegradation of AFB(1) by the isolate was examined by high performance liquid chromatography, and liquid chromatography mass spectrometry; (3) Results: a bacterial strain exhibiting strong AFB(1) degradation activity (91.5%) was isolated and identified as Bacillus velezensis DY3108. The AFB(1) degrading activity was predominantly attributed to the cell-free supernatant of strain DY3108. Besides, it was heat-stable and resistant to proteinase K treatment but sensitive to sodium dodecyl sulfate treatment. The optimal temperature for the maximal degradation of AFB(1) was 80 degrees C. Even more notable, the supernatant showed a high level of activity over a broad pH (4.0 to 11.0) and exhibited the highest degradation (94.70%) at pH 8.0. Cytotoxicity assays indicated that the degradation products displayed significantly (p < 0.05) lower cytotoxic effects than the parent AFB(1); (4) Conclusions: B. velezensis DY3108 might be a promising candidate for exploitation in AFB(1) detoxification and bioremediation in food and feed matrices.