Food Safety Research Center (Salt), Semnan University of Medical Sciences, Semnan, Iran.
Department of Food Technology Research, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Probiotics Antimicrob Proteins. 2022 Jun;14(3):464-475. doi: 10.1007/s12602-021-09810-7. Epub 2021 Jun 15.
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 (10-10 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 10 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。使用 Box-Behnken 设计进行响应面法 (RSM)，以研究包括 pH（5-7）、孵育时间（1-24 小时）、细胞密度（10-10 cfu/mL）和初始 BaP 浓度（5-15 mg/kg）在内的四个独立变量的影响，以评估体外 BaP 的去除率作为响应值。结果表明，所有测试菌株均能从 PBS 中去除 BaP，这种减少完全是菌株特异性的。双歧杆菌 BB-12 紧随其后的是干酪乳杆菌 TD10 表现出最低的结合能力，而最高的结合率与嗜酸乳杆菌 LA-5、德氏乳杆菌保加利亚亚种 PTCC 1737、干酪乳杆菌 TD4 和短乳杆菌 TD3 有关。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明显影响。结果表明，BaP 结合率受 pH、细胞密度、时间和 BaP 浓度的线性和二次影响。此外，细胞密度和时间之间以及时间和 BaP 浓度之间存在相互作用。嗜酸乳杆菌 LA-5 的最高 BaP 结合率为 10 ppm 的 BaP 浓度、pH = 5、细胞密度为 10 cfu/mL 和孵育时间为 24 小时。可以得出结论，基于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最大的 BaP 结合效率。
