College of Food Science, Sichuan Agricultural University, Ya'an 625014, China.
Institute of Food Processing and Safety, Sichuan Agricultural University, Ya'an 625014, China.
Int J Mol Sci. 2022 May 22;23(10):5809. doi: 10.3390/ijms23105809.
3-PBA is a major degradation intermediate of pyrethroids. Its widespread existence in the environment poses a severe threat to the ecosystem and human health. This study evaluated the adsorption capacity of RS20 toward 3-PBA. Batch adsorption experiments indicated that the optimal adsorption conditions were a temperature of 37 °C and initial pH of 6.0-8.0, under which the removal rate was positively correlated with the cell concentration. In addition, there was no link between the incubation time and adsorption rate. The kinetic study showed that the adsorption process fitted well with the pseudo-second-order model, and the adsorption isotherms could be described by both Langmuir and Freundlich equations. Heat and acid treatments showed that the ability of strain RS20 in removing 3-PBA was independent of microbial vitality. Indeed, it was involved with chemisorption and physisorption via the cell walls. The cell walls made the highest contribution to 3-PBA removal, according to the adsorption experiments using different cellular components. This finding was further reconfirmed by SEM. FTIR spectroscopy analysis indicated that carboxyl, hydroxyl, amino groups, and -C-N were the functional sites for the binding of 3-PBA. The co-culture experiments showed that the adsorption of strain RS20 enhanced the degradation of 3-PBA by strain SC-1. Strain RS20 could also survive and effectively remove 3-PBA in simulated digestive juices. Collectively, strain RS20 could be employed as a biological detoxification agent for humans and animals by eliminating 3-PBA from foods, feeds, and the digestive tract in the future.
3-PBA 是拟除虫菊酯的主要降解中间产物。它在环境中的广泛存在对生态系统和人类健康构成了严重威胁。本研究评估了 RS20 对 3-PBA 的吸附能力。批量吸附实验表明,最佳吸附条件为温度 37°C,初始 pH 值为 6.0-8.0,在此条件下,去除率与细胞浓度呈正相关。此外,孵育时间与吸附速率之间没有关联。动力学研究表明,吸附过程符合拟二级模型,吸附等温线可以用 Langmuir 和 Freundlich 方程描述。热和酸处理表明,RS20 菌株去除 3-PBA 的能力与其微生物活力无关。事实上,它通过细胞壁参与化学吸附和物理吸附。根据使用不同细胞成分进行的吸附实验,细胞壁对 3-PBA 的去除贡献最大。这一发现通过 SEM 进一步得到证实。傅里叶变换红外光谱分析表明,羧基、羟基、氨基和 -C-N 是与 3-PBA 结合的功能位点。共培养实验表明,RS20 菌株的吸附增强了 SC-1 菌株对 3-PBA 的降解。RS20 菌株也可以在模拟消化液中存活并有效地去除 3-PBA。总的来说,RS20 菌株未来可以作为一种生物解毒剂,从食物、饲料和消化道中去除 3-PBA,用于人类和动物。