The In Vitro Adsorption Ability of Lactobacillus acidophilus NCFM to Benzo(a)pyrene in PM2.5.

The objective of this work was to explore the ability of lactic acid bacteria strains to bind benzo(a)pyrene (B(a)P) existing in PM2.5. In this study, we examined the ability of Lactobacillus acidophilus NCFM to bind B(a)P in the simulated PM2.5 environment. Among the tested 5 strains, Lactobacillus acidophilus NCFM exhibited the best capacity to bind B(a)P, and its B(a)P binding percentage was 60.00%. Simulations of organic and inorganic systems which represent PM2.5 indicated that B(a)P could be absorbed by strain L. acidophilus NCFM. For the inorganic system of pH 5, L. acidophilus NCFM bound 92.74% B(a)P with a cell concentration of 1 × 1010 cfu/mL at 37°C for 8 hr. Regarding the organic system with pH 6, 73.00% B(a)P was bound by strain L. acidophilus NCFM after this bacterium was incubated at 37°C for 10 min. A quick B(a)P binding by this probiotic bacterium took place in the organic system. The removal of B(a)P from PM2.5 was significantly related to incubation time, cultivation temperature, pH, and cell concentration. Thus, our finding shows that long-term consumption of L. acidophilus NCFM is beneficial for the reduction of B(a)P towards the population who are exposed to PM2.5, although the ability of this bacterium to adsorb B(a)P is partly affected by the differences in the origin of PM2.5.