Shenzhen Prevention and Treatment Center for Occupational Diseases, 2019 Buxin Road, Shenzhen 518020, China.
Shenzhen Prevention and Treatment Center for Occupational Diseases, 2019 Buxin Road, Shenzhen 518020, China; School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan 430030, China.
Ecotoxicol Environ Saf. 2023 Nov 15;267:115662. doi: 10.1016/j.ecoenv.2023.115662. Epub 2023 Nov 6.
Lead (Pb), a naturally occurring element, is redistributed in the environment mainly due to anthropogenic activities. Pb pollution is a crucial public health problem worldwide due to its adverse effects. Environmental bacteria have evolved various protective mechanisms against high levels of Pb. The pbr operon, first identified in Cupriavidus metallidurans CH34, encodes a unique Pb(II) resistance mechanism involving transport, efflux, sequestration, biomineralization, and precipitation. Similar pbr operons are gradually found in diverse bacterial strains. This review focuses on the pbr-encoded Pb(II) resistance system. It summarizes various whole-cell biosensors harboring artificially designed pbr operons for Pb(II) biomonitoring with fluorescent, luminescent, and colorimetric signal output. Optimization of genetic circuits, employment of pigment-based reporters, and screening of host cells are promising in improving the sensitivity, selectivity, and response range of whole-cell biosensors. Engineered bacteria displaying Pb(II) binding and sequestration proteins, including PbrR and its derivatives, PbrR2 and PbrD, for adsorption are involved. Although synthetic bacteria show great potential in determining and removing Pb at the nanomolar level for environmental protection and food safety, some challenges must be addressed to meet demanding application requirements.
铅（Pb）是一种自然存在的元素，主要由于人为活动而在环境中重新分布。由于其不利影响，Pb 污染是一个全球性的重要公共卫生问题。环境细菌已经进化出各种针对高水平 Pb 的保护机制。pbr 操纵子最初在 Cupriavidus metallidurans CH34 中被鉴定，它编码了一种独特的 Pb(II)抗性机制，涉及运输、外排、螯合、生物矿化和沉淀。类似的 pbr 操纵子在不同的细菌菌株中逐渐被发现。本综述重点介绍了 pbr 编码的 Pb(II)抗性系统。它总结了各种含有人工设计的 pbr 操纵子的全细胞生物传感器，用于 Pb(II)生物监测，具有荧光、发光和比色信号输出。遗传电路的优化、色素报告基因的使用和宿主细胞的筛选有望提高全细胞生物传感器的灵敏度、选择性和响应范围。涉及到展示 Pb(II)结合和螯合蛋白的工程菌，包括 PbrR 及其衍生物 PbrR2 和 PbrD，用于吸附。尽管合成细菌在纳米级水平上用于环境保护和食品安全的 Pb 测定和去除方面显示出巨大的潜力，但为了满足苛刻的应用要求，仍需要解决一些挑战。
