In this study, the ability of various lactic acid bacteria was assessed in removing benzo[a]pyrene (BaP) from contaminated phosphate buffer saline (PBS). Response surface methodology (RSM) was performed using Box-Behnken design to investigate the effect of four independent variables including pH (5–7), incubation time (1–24 h), cell density (10⁷–10⁹ cfu/mL), and initial BaP concentration (5–15 mg/kg) at three levels to evaluate in vitro removal of BaP as response. The results showed that all the tested strains were able to remove BaP from PBS and this reduction was entirely strain-specific. Bifidobacterium lactis BB-12 followed by Lactobacillus casei TD10 exhibited the lowest binding ability while the highest binding rate was related to Lactobacillus acidophilus LA-5, Lactobacillus delbrueckii subsp. bulgaricus PTCC 1737, Lactobacillus casei TD4, and Lactobacillus brevis TD3, respectively. Cyclohexane washing weakened BaP-bacteria complex, while this complex was not significantly changed by PBS washing. The results showed that BaP binding rate was influenced by pH, cell density, time, and BaP concentration in linear and quadratic manners. Moreover, there were interactions between cell density and time as well as between time and BaP concentration. The highest BaP-binding rate by L. acidophilus LA-5 was 10 ppm of BaP concentration, pH = 5, cell density of 10⁹ cfu/mL, and an incubation period of 24 h. It can be concluded that a range of pH, time, and microbial population is required to obtain maximum binding efficiency for BaP based on the concentration of the toxin and the species of the bacteria.

在这项研究中，评估了各种乳酸菌从受污染的磷酸盐缓冲盐水 (PBS) 中去除苯并 [a] 芘 (BaP) 的能力。响应面法 (RSM) 使用 Box-Behnken 设计来研究四个自变量的影响，包括 pH (5–7)、孵育时间 (1–24 h)、细胞密度 (10 ⁷ –10 ⁹  cfu/mL) ，以及三个水平的初始 BaP 浓度（5-15 mg/kg），以评估体外去除 BaP 的反应。结果表明，所有测试的菌株都能够从 PBS 中去除 BaP，并且这种降低完全是菌株特异性的。乳酸双歧杆菌BB-12，然​​后是干酪乳杆菌TD10 的结合能力最低，而结合率最高的与嗜酸乳杆菌LA-5、德氏乳杆菌亚种有关。保加利亚乳杆菌PTCC 1737、干酪乳杆菌TD4 和短乳杆菌TD3。环己烷洗涤削弱了BaP-细菌复合物，而PBS洗涤对该复合物没有显着改变。结果表明，BaP结合率受pH、细胞密度、时间和BaP浓度的影响呈线性和二次方。此外，细胞密度与时间以及时间与 BaP 浓度之间存在相互作用。嗜酸乳杆菌的最高 BaP 结合率LA-5 的 BaP 浓度为 10 ppm，pH = 5，细胞密度为 10 ⁹  cfu/mL，潜伏期为 24 小时。可以得出结论，根据毒素浓度和细菌种类，需要一定范围的 pH、时间和微生物种群才能获得 BaP 的最大结合效率。