Potential of Animal Excreta as a Source of Probiotic Lactic Acid Bacteria for Aflatoxin B1 Detoxification by the Surface Binding Mechanism

Abstract

Aflatoxins (AFs) are the most potent and ubiquitously found mycotoxins, capable of causing contamination in agricultural products. Aflatoxin B1 (AFB1) is the most toxic and primarily produced Aflatoxin and will be a real threat to the safety of food and feeds. The current study searched for the potential of Lactic acid bacteria (LAB) isolated from animal excreta for AFB1 mitigation. Three LAB out of 56 isolates were found to exhibit more than 50% sorbent action with AFB1 in phosphate-buffered saline (PBS) and were identified as Lactococcuslactis strain CF_6 (OP183481) (65.38%), Lacticaseibacillus casei strain CW_3 (OP183482)(52.63%) and Lactobacillus acidophilus strain CE_4 (OP183483)(63.13%). More than 60% of the total AFB1 removal was observed in 2 hr of incubation, and maximum sorbent action was found at a pH 6-7 range at 37oC for 24 hours. In the Scanning Electron Microscope (SEM) analysis, heat-killed cells showed a significant increase in cell surface binding area, which improved the surface binding for all isolates except L. casei strain CW_3; however, it proves that LAB surface binding is strain-specific rather than heat treatment. Moreover, the rise in AFB1 concentration improved the rate of the sorbent action but did not observe any substantial changes in total AFB1 detoxification. So, it is concluded that the animal excreta may be a versatile source of probiotic LAB for AFB1 detoxification by surface binding.