It is of great interest to explore physiological metabolism of electrochemically active bacteria (EAB) for combined organics and heavy metals in single-chamber microbial electrolysis cells (MECs). Four pure culture EAB varying degrees responded to the combined acetate (1.0–5.0 g/L) and Cd(II) (20–150 mg/L) at different initial concentrations in the single-chamber MECs, shown as significant relevance of Cd(II) removal (2.57–7.35 mg/L/h) and H₂ production (0–0.0011 m³/m³/h) instead of acetate removal (73–130 mg/L/h), to these EAB species at initial Cd(II) below 120 mg/L and initial acetate below 3.0 g/L. A high initial acetate (5.0 g/L) compensated the Cd(II) inhibition and broadened the removal of Cd(II) to 150 mg/L. These EAB physiologically released variable amounts of extracellular polymeric substances with a compositional diversity in response to the changes of initial Cd(II) and circuital current whereas the activities of typical intracellular enzymes were more apparently altered by the initial Cd(II) than the circuital current. These results provide experimental validation of the presence, the metabolic plasticity and the physiological response of these EAB directed by the changes of initial Cd(II) and acetate concentrations in the single-chamber MECs, deepening our understanding of EAB physiological coping strategies in metallurgical microbial electro-ecological cycles.

探索电化学活性细菌 (EAB) 在单室微生物电解池 (MEC) 中对有机物和重金属的生理代谢具有重要意义。四种纯培养 EAB 对单室 MEC 中不同初始浓度的醋酸盐 (1.0-5.0 g/L) 和 Cd(II) (20-150 mg/L) 有不同程度的响应，显示为 Cd( II) 去除 (2.57–7.35 mg/L/h) 和 H ₂产量 (0–0.0011 m ³ /m ³/h) 而不是去除乙酸盐 (73–130 mg/L/h)，在初始 Cd(II) 低于 120 mg/L 和初始乙酸盐低于 3.0 g/L 时去除这些 EAB 物种。较高的初始乙酸盐 (5.0 g/L) 补偿了 Cd(II) 抑制作用，并将 Cd(II) 的去除范围扩大到 150 mg/L。这些 EAB 在生理上释放出不同数量的细胞外聚合物，其组成多样性响应于初始 Cd(II) 和电路电流的变化，而典型细胞内酶的活性更明显地被初始 Cd(II) 改变而不是电路电流. 这些结果为这些 EAB 的存在、代谢可塑性和生理反应提供了实验验证，这些 EAB 由单室 MEC 中初始 Cd(II) 和乙酸盐浓度的变化指导，