Bed electrodes provide high electrode area‐to‐volume ratios represent a promising configuration for transferring bioelectrochemical systems close to industrial applications. Nevertheless, the intrinsic electrical resistance leads to poor polarization behavior. Therefore, the distribution of Geobacter spp. and their electrochemical performance within exemplary fixed‐bed electrodes are investigated. A minimally invasive sampling system allows characterization of granules from different spatial locations of bed electrodes. Cyclic voltammetry of single granules (n=63) demonstrates that the major share of electroactivity (134.3 mA L⁻¹) is achieved by approximately 10 % of the bed volume, specifically that being close to the current collector. Nevertheless, analysis of the microbial community reveals that Geobacter spp. dominated all sampled granules. These findings clearly demonstrate the need for engineered bed electrodes to improve electron exchange between microorganisms and granules.

中文翻译：

---

固定床电极的氧化还原电位异质性导致微生物分层和性能不均匀

床电极提供高电极面积与体积比，代表了将生物电化学系统转移到接近工业应用的有前景的配置。然而，固有的电阻导致较差的极化行为。因此，地杆菌属的分布。并研究了它们在示例性固定床电极中的电化学性能。微创采样系统可以对来自床电极不同空间位置的颗粒进行表征。单颗粒（n = 63）的循环伏安法表明，电活性的主要部分（134.3 mA L ^-1）是通过大约10%的床体积实现的，特别是靠近集电器的床体积。然而，对微生物群落的分析表明，地杆菌属。主导了所有采样颗粒。这些发现清楚地表明需要工程床电极来改善微生物和颗粒之间的电子交换。