[Binding of benzo(a)pyrene by Lactobacilli strains].

We studied the ability of Lactobacillus plantarum 121 and Lactobacillus pentosus ML32 to bind benzo(a)pyrene. The percentage of benzo(a)pyrene bound by the lactobacilli strains was quantitated by HPLC after bacterial cells and benzo(a)pyrene were co-incubated in MRS media at 37 degrees C for 4 h. The percentage of benzo(a)pyrene-binding was 65.9% for 121 and 64.9% for ML32. Physical factors affecting binding ability included incubation time, temperature, bacterial cell viability, pH and concentrations of Ca2+ and Mg2+. Different chemical and enzymatic treatments to cells affected the binding of the two strains to benzo(a)pyrene. The simulation of gastrointestinal environments showed that the binding ability of the two strains depended largely upon pH and bile salt concentrations, but less upon treating time. Trypsin had only influence on the ability of 121 to bind benzo(a)pyrene. The presence of benzene in washing cell impaired the ability of the two strains to bind benzo(a)pyrene. Strains 121 and ML32 had potential to bind benzo(a)pyrene.