The Effect of Bovine Serum Albumin on Benzo[a]pyrene Removal by <i>Lactobacillus</i> Strains

Abstract

The aim of this study was to investigate the influence of bovine serum albumin (BSA) on the Lactobacillus-strain-mediated removal of benzo[a]pyrene (BaP). A combination of 0.5 mg/mL of BSA with 1.0 × 1010 CFU/mL bacterial cells had a removal of 49.61% BaP for strain 121, while a combination of 0.4 mg/mL of BSA with 1.0 × 1010 CFU/mL bacterial cells had a removal of 66.09% BaP for strain ML32. The results indicated that the binding of BaP to Lactobacillus-BSA was stable. BSA maintains Lactobacillus activity and BaP removal in the gastrointestinal environment. Heat and ultrasonic treatment of BSA reduced the BaP-binding ability of Lactobacillus–BSA. With the addition of BSA, the surface properties of the two strains affected BaP binding. The Fourier-transform infrared (FTIR) data demonstrated that O-H, N-H, C=O, and P=O groups were involved in the binding of BaP to Lactobacillus–BSA. Scanning electron microscopy (SEM) results revealed that the morphology of Lactobacillus–BSA bound to BaP was maintained. The adsorption of BaP by Lactobacillus–BSA was appropriately described by the pseudo-second-order kinetic model and Freundlich isotherm model. BSA enhances the affinity between the bacterial cells and BaP.

Keywords

• benzo[a]pyrene
• <i>Lactobacillus</i>
• bovine serum albumin
• binding mechanism
• adsorption kinetics model
• adsorption isotherms model