Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA.
J Ind Microbiol Biotechnol. 2023 Feb 17;50(1). doi: 10.1093/jimb/kuad020.
Biogenic synthesis of inorganic nanomaterials has been demonstrated for both wild and engineered bacterial strains. In many systems the nucleation and growth of nanomaterials is poorly controlled and requires concentrations of heavy metals toxic to living cells. Here, we utilized the tools of synthetic biology to engineer a strain of Escherichia coli capable of synthesizing cadmium sulfide nanoparticles from low concentrations of reactants with control over the location of synthesis. Informed by simulations of bacterially-assisted nanoparticle synthesis, we created a strain of E. coli expressing a broad-spectrum divalent metal transporter, ZupT, and a synthetic CdS nucleating peptide. Expression of ZupT in the outer membrane and placement of the nucleating peptide in the periplasm focused synthesis within the periplasmic space and enabled sufficient nucleation and growth of nanoparticles at sub-toxic levels of the reactants. This strain synthesized internal CdS quantum dot nanoparticles with spherical morphology and an average diameter of approximately 3.3 nm.
ONE-SENTENCE SUMMARY: Expression of a metal ion transporter regulates synthesis of cadmium sulfide nanoparticles in bacteria.
已经证明，野生和工程化的细菌菌株都可以进行无机纳米材料的生物合成。在许多系统中，纳米材料的成核和生长都难以控制，需要使用对活细胞有毒的重金属浓度。在这里，我们利用合成生物学的工具，设计了一种能够从低浓度反应物中合成硫化镉纳米颗粒的大肠杆菌菌株，并能够控制合成的位置。受细菌辅助纳米颗粒合成模拟的启发，我们创建了一种表达广谱二价金属转运蛋白 ZupT 和合成 CdS 成核肽的大肠杆菌菌株。ZupT 在外膜中的表达和成核肽在周质中的定位将合成集中在周质空间内，从而在亚毒性反应物水平下实现了足够的成核和生长。该菌株在内部合成了具有球形形态和平均直径约为 3.3nm 的 CdS 量子点纳米颗粒。
金属离子转运蛋白的表达调控了细菌中硫化镉纳米颗粒的合成。
