Sustainable conversion of antibiotic wastewater using microbial fuel cells: Energy harvesting and resistance mechanism analysis

In this study, tetracycline (TC) can be degraded in microbial fuel cells (MFCs) rapidly and efficiently for the synergistic effect of microbial metabolism and electrical stimulation. Different TC concentrations had different effects on the bioelectric performance of MFCs. Among them, 10 mg/L TC promoted the bioelectric properties of MFCs, the maximum power density reached 1744.4 +/- 74.9 mW/cm2. In addition, we demonstrated that Geo-bacter and Chryseobacterium were the dominant species in the anode biofilm, while Azoarcus and Pseudomonas were the prominent species in the effluent, and the initial TC concentration affected the microbial community composition. Furthermore, the addition of TC increased the relative abundance of aadA3, sul1, adeF, cmlA, and tetC in reactors, indicating that a single antibiotic could promote the expression of self-related resistance as well as the expression of other ARGs. Moreover, the presence of TC can increase the relative content of mobile genetic elements (MGEs) and greatly increase the risk of antibiotic resistance genes (ARGs) spreading. Meanwhile, network analysis revealed that some microorganisms (such as Acidovorax caeni, Geobacter soil, and Pseudomonas thermotolerans) and MGEs may be potential hosts for multiple ARGs.

Automated summary

Tetracycline (TC) can be rapidly and efficiently degraded in microbial fuel cells (MFCs) due to the synergistic effect of microbial metabolism and electrical stimulation. Different TC concentrations have varying effects on the bioelectric performance of MFCs, with 10 mg/L TC promoting properties such as a maximum power density of 1744.4 +/- 74.9 mW/cm2. The microbial community composition in the MFCs is affected by the initial TC concentration, with Geo-bacter and Chryseobacterium being dominant in the anode biofilm and Azoarcus and Pseudomonas being prominent in the effluent. Furthermore, the presence of TC leads to an increase in the relative abundance of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs), posing a greater risk of ARGs spreading, and network analysis suggests certain microorganisms and MGEs may serve as potential hosts for multiple ARGs.