Microorganisms regulate the redox state of different biomolecules to precisely control biological processes. These processes can be modulated by electrochemically coupling intracellular biomolecules to an external electrode, but current approaches afford only limited control and specificity. Here we describe specific electrochemical control of the reduction of intracellular biomolecules in Escherichia coli through introduction of a heterologous electron transfer pathway. E. coli expressing mtrCAB from Shewanella oneidensis MR-1 consumed electrons directly from a cathode when fumarate or nitrate, both intracellular electron acceptors, were present. The fumarate-triggered current consumption occurred only when fumarate reductase was present, indicating all the electrons passed through this enzyme. Moreover, MtrCAB-expressing E. coli used current to stoichiometrically produce ammonia. Thus, our work introduces a modular genetic tool to reduce a specific intracellular redox molecule with an electrode, opening the possibility of electronically controlling biological processes such as biosynthesis and growth in any microorganism.

中文翻译：

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使用遗传模块精确控制大肠杆菌内部的氧化还原反应

微生物调节不同生物分子的氧化还原状态，以精确控制生物过程。这些过程可通过将细胞内生物分子电化学偶联到外部电极来调节，但是目前的方法仅提供有限的控制和特异性。在这里，我们描述了通过引入异源电子转移途径减少大肠杆菌中细胞内生物分子的特异性电化学控制。大肠杆菌表达mtrCAB从希瓦氏菌oneidensis中当存在两种胞内电子受体的富马酸盐或硝酸盐时，MR-1直接从阴极消耗电子。仅当存在富马酸酯还原酶时，才会发生富马酸酯触发的电流消耗，这表明所有电子都通过了该酶。而且，表达MtrCAB的大肠杆菌使用电流以化学计量产生氨。因此，我们的工作引入了一种模块化遗传工具，可通过电极减少特定的细胞内氧化还原分子，从而为电子控制生物过程（例如任何微生物的生物合成和生长）提供了可能性。