Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
Sci Total Environ. 2022 Oct 20;844:157158. doi: 10.1016/j.scitotenv.2022.157158. Epub 2022 Jul 5.
The electrochemical activity of bioelectrochemical systems (BESs) was proven to be dependent on the stability of electroactive biofilms (EABs), but the response of EABs based on real wastewater to external disturbances is not fully known. Herein, we used real wastewater (beer brewery wastewater) as a substrate for culturing EABs and found that current generation, biomass, redox activity and extracellular polymeric substances (EPS) content in those EABs were lower as compared to EABs cultured with synthetic wastewaters (acetate and glucose). However, the EABs from the beer brewery wastewater showed moderate anti-shock resistance capability. The proteins and humic acid in loosely bound EPS (LB-EPS) exhibited a positive linear relationship with current recovery after Ag shock, indicating the importance of LB-EPS for protecting the EABs. Fluorescence and Fourier transform infrared spectroscopy integrated with two-dimensional correlation spectroscopy verified that the spectra of the protein-like region of LB-EPS changed considerably under the interference of Ag concentration and the CO group of humic acid or proteins was mainly responsible for binding with Ag to attenuate its toxicity to the EABs. This is the first study revealing the underlying molecular mechanism of EABs cultured with real wastewater against external heavy metal shock and provides useful insights into enhancing the application of BESs in future water treatment.
生物电化学系统（BES）的电化学活性被证明依赖于电活性生物膜（EAB）的稳定性，但基于实际废水的 EAB 对外部干扰的响应尚不完全清楚。在此，我们使用实际废水（啤酒酿造废水）作为培养 EAB 的底物，发现与用合成废水（乙酸盐和葡萄糖）培养的 EAB 相比，那些 EAB 的电流产生、生物量、氧化还原活性和细胞外聚合物物质（EPS）含量较低。然而，啤酒酿造废水中的 EAB 表现出中等的抗冲击能力。松散结合 EPS（LB-EPS）中的蛋白质和腐殖酸与 Ag 冲击后的电流恢复呈正线性关系，表明 LB-EPS 对保护 EAB 的重要性。荧光和傅里叶变换红外光谱与二维相关光谱相结合，验证了 LB-EPS 中类蛋白质区域的光谱在 Ag 浓度的干扰下发生了很大变化，腐殖酸或蛋白质的 CO 基团主要负责与 Ag 结合，从而减轻其对 EAB 的毒性。这是第一项揭示用实际废水培养的 EAB 对抗外部重金属冲击的潜在分子机制的研究，为增强未来水处理中 BES 的应用提供了有用的见解。
