Shi Xiaoshuo, Qi Jiaran, He Yuanzhu, Mi Wenxian, Liu Xiaohong
Anhui Agricultural University, No. 130, Changjiang West Road, Hefei, 230036, Anhui Province, China.
Bioprocess Biosyst Eng. 2025 Aug 25. doi: 10.1007/s00449-025-03226-1.
The bioremediation of penoxsulam, a commonly encountered aquatic herbicide, was investigated using a single-chamber air microbial fuel cell (MFC) system. This study focused on how the modulation of electron transfer through exogenous electron shuttles (riboflavin (RF), anthraquinone-2-sulfonate (AQS)) and respiratory inhibitors (rotenone, capsaicin) affects electrogenesis and the degradation of penoxsulam. The addition of electron shuttles significantly improved both MFC power generation and pollutant removal efficiency in a dose-dependent manner, with optimal concentrations identified for maximum performance. In contrast, respiratory inhibitors strongly suppressed both processes, leading to an increase in charge transfer resistance. This study links macroscopic changes in performance with intracellular bioenergetic parameters, showing that electron shuttles maintain higher intracellular NAD levels and current densities, likely by promoting NAD regeneration, whereas inhibitors deplete NAD availability and hinder electron flow. Additionally, an analysis of key respiratory enzymes indicated that Cytochrome C oxidase plays an important role in facilitating extracellular electron transfer to the anode. Inhibitor studies provide further support for the importance of Complex I and downstream cytochrome pathways for power generation and degradation. By establishing the relationships between mechanisms and performance and proposing an integrated electron transfer model, this research highlights important enzymatic and metabolic control points for optimizing MFC-based bioremediation. These findings provide important insights into enhancing bioelectrochemical systems for concurrent environmental remediation and sustainable energy recovery.
利用单室空气微生物燃料电池（MFC）系统研究了常见的水生除草剂五氟磺草胺的生物修复。本研究重点关注通过外源电子穿梭体（核黄素（RF）、蒽醌-2-磺酸盐（AQS））和呼吸抑制剂（鱼藤酮、辣椒素）调节电子转移如何影响产电和五氟磺草胺的降解。添加电子穿梭体以剂量依赖的方式显著提高了MFC的发电和污染物去除效率，并确定了最佳浓度以实现最大性能。相比之下，呼吸抑制剂强烈抑制了这两个过程，导致电荷转移电阻增加。本研究将性能的宏观变化与细胞内生物能量参数联系起来，表明电子穿梭体可能通过促进NAD再生来维持较高的细胞内NAD水平和电流密度，而抑制剂会耗尽NAD的可用性并阻碍电子流动。此外，对关键呼吸酶的分析表明，细胞色素C氧化酶在促进细胞外电子向阳极转移方面起着重要作用。抑制剂研究进一步支持了复合体I和下游细胞色素途径对发电和降解的重要性。通过建立机制与性能之间的关系并提出一个综合电子转移模型，本研究突出了优化基于MFC的生物修复的重要酶促和代谢控制点。这些发现为增强生物电化学系统以同时进行环境修复和可持续能源回收提供了重要见解。
