In this work we employ differential electrochemical mass spectrometry (DEMS) in combination with static and dynamic electrochemical techniques for the study of metabolic processes of electrochemically active bacteria. CO₂ production during acetate oxidation by electrode respiring bacteria was measured, in-vivo and online with a sensitivity of 6.5 ⋅ 10⁻¹³ mol/s. The correlation of ion current and electrical current provides insight into the interaction of metabolic processes and extra-cellular electron transfer. In low-turnover CVs, two competing potential dependent electron transfer mechanisms were observed and formal potentials of two redox systems that are involved in complete oxidation of acetate to CO₂ were determined. By balancing charge and carbon flows during dynamic measurements, two significant storage mechanisms in electrochemically active bacteria were identified: 1) a charge storage mechanism that allows substrate oxidation to proceed at a constant rate despite of external current flowing in cathodic direction. 2) a carbon storage mechanism that allows the biofilm to take up acetate at an unchanged rate at very low potentials even though the oxidation to CO₂ stops. These storage capabilities allow a limited decoupling of electrical current and CO₂ production rate.

在这项工作中，我们采用差动电化学质谱（DEMS）结合静态和动态电化学技术来研究电化学活性细菌的代谢过程。测量了体内和在线电极呼吸细菌在乙酸盐氧化过程中产生的CO ₂，灵敏度为6.5⋅10 ^-13 mol / s。离子电流和电流的相关性提供了对代谢过程与细胞外电子转移相互作用的洞察力。在低周转量的CV中，观察到两个相互竞争的，依赖于电势的电子转移机制，并且涉及两个完全将乙酸盐氧化为CO _2的氧化还原系统的形式电势被确定。通过在动态测量过程中平衡电荷和碳的流动，可以确定电化学活性细菌中的两种重要的存储机制：1）一种电荷存储机制，尽管外部电流沿阴极方向流动，该机制仍可以使底物以恒定速率进行氧化。2）碳存储机制，即使停止氧化成CO ₂，生物膜也可以以极低的电位以不变的速率吸收乙酸盐。这些存储功能允许电流和CO ₂生产率的有限解耦。