Enhanced power generation in microbial fuel cell by an agonist of electroactive biofilm – Sulfamethoxazole

Electroactive biofilm (EABF) is equipped with the capability of direct extracellular electron transfer. It is commonly employed in bioelectrochemical system (BES) for organics conversion and pollutants removal. In this study, for the first time, we find out one type of antibiotics namely sulfamethoxazole (SMX) can increase the activity and performance of EABF in microbial fuel cell (MFC). The results confirm that SMX acted as an agonist in promoting the regulation of EABF. The maximum power density increased by 18% with the presence of 20 mg L⁻¹ SMX in comparison to 1 g L⁻¹ acetate sodium as sole carbon source. Moreover, the energy efficiency also increased by almost 3-fold to 9.6 KW·h kg⁻¹. Meanwhile, SMX can be completely transformed to other by-products via various pathways without inhibiting the performance of MFC. Interestingly, microbial community analysis shows the presence of SMX removed the competitive population in the anode and enhanced the abundance of exoelectrogens, suggesting another possible mechanism for energy enhancement. This study demonstrates that some organics which are toxic and bio-refractory, such as antibiotics, can be used to alter the microbial communities to enhance the performance of electricity generation.