Efficiency of Lactic Acid Bacteria Strains for Decontamination of Aflatoxin M1 in Phosphate Buffer Saline Solution and in Skimmed Milk

The aim of this study was to evaluate the ability of seven lactic acid bacteria (LAB) strains to remove aflatoxin M-1 (AFM(1)) in phosphate buffer saline (PBS) and in skimmed milk samples. The mean AFM(1) removal by LAB in PBS ranged from 5.60 +/- 0.45% to 45.67 +/- 1.65% (n = 3). Heat-killed cells showed AFM(1) removal percentages significantly higher than viable cells in contact times of 15 min or 24 h, although there were no significant differences between those times. AFM(1)/LAB complex resulted from tests with PBS was unstable, as 40.57 +/- 4.66% to 87.37 +/- 1.82% of AFM(1) retained by bacteria were recovered in solution after washing with PBS. Heat-killed cells of Lactobacillus rhamnosus, Lactobacillus delbrueckii spp. bulgaricus, and Bifidobacterium lactis had the highest percentage (> 33%) of AFM(1) removal in PBS tests. In ultrahigh temperature (UHT) skimmed milk spiked with AFM(1), the three selected LAB strains showed no significant differences in removing AFM(1) at 37 A degrees C, and only B. lactis had greater ability to remove AFM(1) at 4 A degrees C. Results demonstrated that AFM(1) removal by LAB has a potential application to reduce toxin concentrations until safe levels in milk.