摘要
      为了研究生物电化学系统中铬和铜胁迫下磺酰胺废水处理的电化学过程和代谢机制，研究了电子转移和抗生素抗性基因（ARGs）转移。利用宏基因组学揭示了代谢途径、抗生素抗性机制、碳水化合物活性酶等。结果表明，铜胁迫不仅不影响电化学系统的发电性能，而且提高了电子转移效率。铜胁迫还可以有效控制ARGs和可移动遗传元件（MGE）。宏基因组学分析表明，Cu增加了电化学系统中coxA和cox1基因的丰度，并增加了C型细胞色素，从而提高了电子转移能力。相反，铬应力影响电化学系统的性能，加速ARGs的转移，并增加了抗性基因水平转移的风险。抗生素耐药性的机制主要是通过抗生素（61.5%）的外排功能，主要与变形杆菌（51.5%）和厚壁菌门（25.4%）有关。结果还表明，铜促进了糖酵解过程，而铬对糖酵解进程产生了负面影响。本研究揭示了铬和铜胁迫在遗传水平上对生物电化学系统中微生物代谢机制的影响，为畜禽废水的风险控制提供了理论依据。
Abstract
To investigate the electrochemical process and metabolic mechanism of sulfonamide wastewater treatment under chromium and copper stress in bioelectrochemical system, electron transfer and antibiotic resistance genes (ARGs) transfer were investigated. Metagenomics was used to reveal metabolic pathways, antibiotic resistance mechanisms, carbohydrate active enzymes, etc. The results indicated that copper stress not only did not affect the electricity production performance of the electrochemical system, but also promoted the electron transfer efficiency. Copper stress can also effectively control ARGs and mobile genetic elements (MGEs). The metagenomics analysis showed that Cu increased the abundance of coxA and cox1 genes in the electrochemical system and increased the C-type cytochrome, thereby improving the ability of electron transfer. In contrast, chromium stress affected electrochemical system performance and accelerated ARGs transfer, and increasing the risk of resistance gene horizontal transfer. The mechanism of antibiotic resistance was mainly through the efflux function of antibiotics (61.5%), which was mainly related to Proteobacteria (51.5%) and Firmicutes (25.4%). The results also indicated that the glycolysis process was promoted by Cu, while the process was negatively affected by Cr. This study revealed the effect of chromium and copper stress on the metabolic mechanisms of microorganisms in bioelectrochemical system at the genetic level and provided a theoretical basis for risk control of livestock and poultry wastewater.

https://www.sciencedirect.com/science/article/abs/pii/S2213343722019959