In vitro assessment on effect of duodenal contents on the lead (Pb2+) binding capacity of two probiotic bacterial strains

In vitro Lead (Pb 2+ ) binding capacity of two probiotic bacteria strains, namely Bifidobacterium longum BB79 and Lactobacillus pentosus ITA23, was assessed following incubation with the intestinal contents (IC) of laying hens. Results of this study demonstrated that IC treatment significantly enhanced ( P <0.01) Pb 2+ binding capacity of both bacterial strains. Fourier transform infrared analysis indicated that several functional groups (O-H or N-H, C-H, C˭O, C-O, and C-O-C) on the bacteria cell wall involved in metal ion binding were altered after IC incubation, and new groups appeared between the 3700   cm −1 and 4000   cm −1 bands. Transmission electron microscopy demonstrated that after incubation with IC, unidentified IC components created new binding sites on the bacterial cell surface. These particles also changed the mechanism of Pb 2+ binding of the two strains from intracellular accumulation to extracellular adsorption.