Dundas Christopher M, Graham Austin J, Romanovicz Dwight K, Keitz Benjamin K
ACS Synth Biol. 2018 Dec 21;7(12):2726-2736. doi: 10.1021/acssynbio.8b00218. Epub 2018 Nov 9.
The relative scarcity of well-defined genetic and metabolic linkages to material properties impedes biological production of inorganic materials. The physiology of electroactive bacteria is intimately tied to inorganic transformations, which makes genetically tractable and well-studied electrogens, such as Shewanella oneidensis, attractive hosts for material synthesis. Notably, this species is capable of reducing a variety of transition-metal ions into functional nanoparticles, but exact mechanisms of nanoparticle biosynthesis remain ill-defined. We report two key factors of extracellular electron transfer by S. oneidensis, the outer membrane cytochrome, MtrC, and soluble redox shuttles (flavins), that affect Pd nanoparticle formation. Changes in the expression and availability of these electron transfer components drastically modulated particle synthesis rate and phenotype, including their structure and cellular localization. These relationships may serve as the basis for biologically tailoring Pd nanoparticle catalysts and could potentially be used to direct the biogenesis of other metal nanomaterials.
与材料特性明确的遗传和代谢联系相对稀缺，这阻碍了无机材料的生物生产。电活性细菌的生理学与无机转化密切相关，这使得基因易于操作且研究充分的产电菌，如希瓦氏菌，成为材料合成的有吸引力的宿主。值得注意的是，该物种能够将多种过渡金属离子还原为功能性纳米颗粒，但纳米颗粒生物合成的确切机制仍不明确。我们报告了希瓦氏菌胞外电子转移的两个关键因素，即外膜细胞色素MtrC和可溶性氧化还原穿梭体（黄素），它们影响钯纳米颗粒的形成。这些电子转移成分的表达和可用性的变化极大地调节了颗粒合成速率和表型，包括它们的结构和细胞定位。这些关系可能作为生物定制钯纳米颗粒催化剂的基础，并有可能用于指导其他金属纳米材料的生物合成。
