Massazza Diego A, Busalmen Juan P, Romeo Hernán E
Institute of Materials Science and Technology (INTEMA), University of Mar del Plata (Mar del Plata, Argentina) and National Research Council (CONICET, Argentina), Mar del Plata, Argentina.
Commun Biol. 2025 May 2;8(1):692. doi: 10.1038/s42003-025-08125-5.
Studies on electron-transfer pathways in certain bacterial strains have revealed that the degree of coupling of electron transfer to proton translocation along the respiratory chain can be regulated according to metabolic demands. This first line of metabolic response, based on the existence of energy dissipation mechanisms, has not been demonstrated to be a general pattern across the bacterial kingdom, let alone to be operative in electro-active bacteria. In this study, we hypothesized that electro-active cells should respond to over-polarization by also triggering energy decoupling mechanisms to prevent metabolic overloads. Based on electrochemical analyses, we propose that the recently discovered inner-membrane cytochrome CbcBA - used by electro-active Geobacter sulfurreducens bacteria for cellular respiration near the thermodynamic energetic limit - can also act as an energy dissipation gate when the metabolism is demanded, contributing to regulate the energy balance of the cell by decoupling carbon assimilation from electrode respiration.
对某些细菌菌株中电子传递途径的研究表明，电子传递与沿呼吸链的质子转运的偶联程度可根据代谢需求进行调节。基于能量耗散机制的存在，这种代谢反应的第一线尚未被证明是整个细菌界的普遍模式，更不用说在电活性细菌中起作用了。在本研究中，我们假设电活性细胞应通过触发能量解偶联机制来应对过极化，以防止代谢过载。基于电化学分析，我们提出，最近发现的内膜细胞色素CbcBA——电活性的硫还原地杆菌在接近热力学能量极限时用于细胞呼吸——在代谢需要时也可以作为能量耗散门，通过使碳同化与电极呼吸解偶联来调节细胞的能量平衡。
