State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
Department of Chemical and Biomolecular Engineering, Ohio University, Athens, OH, 45701, USA.
Extremophiles. 2020 Jul;24(4):485-499. doi: 10.1007/s00792-020-01170-4. Epub 2020 Apr 22.
During bioleaching of Cobalt from waste lithium-ion batteries, the biooxidation activity of acidophilic bacteria is inhibited by a high concentration of Co ion in the liquid phase. However, the mechanism for Co toxicity to acidophilic bacteria has not been fully elucidated. In this study, the effects of Co concentration on the biooxidation activity for Fe, intracellular reactive oxygen species (ROS) level and antioxidant defense systems in a mixed-culture of acidophilic bacteria (MCAB) were investigated. The results showed that the biooxidation activity of the MCAB was inhibited by Co. Furthermore, it was indicated that the intracellular ROS contents of the MCAB under conditions of 0.4 M and 0.6 M Co were 2.60 and 3.34 times higher than that under the condition of 0 M Co. The increase in intracellular malondialdehyde content indicated that the oxidative damage was induced by Co. Moreover, the antioxidant systems in MCAB were affected by Co. It was observed that the Co exposure increased the catalase and glutathione peroxidase activities while reducing the superoxide dismutase activity and the intracellular glutathione (GSH) content. It was found that an exogenous GSH supplementation eliminated excess intracellular ROS and improved the biooxidation activity of the MCAB.
在从废锂离子电池中生物浸出钴的过程中，液相中高浓度的钴离子会抑制嗜酸细菌的生物氧化活性。然而，钴对嗜酸细菌的毒性机制尚未完全阐明。本研究考察了钴浓度对混合嗜酸细菌（MCAB）生物氧化活性、细胞内活性氧（ROS）水平和抗氧化防御系统的影响。结果表明，钴抑制了 MCAB 的生物氧化活性。此外，结果表明，在 0.4 M 和 0.6 M Co 条件下，MCAB 的细胞内 ROS 含量分别比 0 M Co 条件下高 2.60 倍和 3.34 倍。丙二醛含量的增加表明氧化损伤是由 Co 引起的。此外，MCAB 的抗氧化系统也受到 Co 的影响。观察到 Co 暴露增加了过氧化氢酶和谷胱甘肽过氧化物酶的活性，同时降低了超氧化物歧化酶的活性和细胞内谷胱甘肽（GSH）的含量。研究发现，外源 GSH 补充消除了过量的细胞内 ROS，并提高了 MCAB 的生物氧化活性。
