Turning Motion into Methane: Electromagnetic Induction in Microbial Aggregates Enhances Wastewater Resource Recovery

Microbial aggregates in wastewater treatment systems generate substantial kinetic energy through their motion, which constitutes ubiquitous but untapped energy. Here, we demonstrate that this kinetic energy can be harvested and converted into bioavailable electrochemical potential to drive the microbial metabolism. In anaerobic reactors, aggregates moving perpendicular to a designed magnetic field generate an in situ electrical potential via electromagnetic induction through their conductive pili networks, thereby enabling the direct conversion of microbial motion into methane via metabolic energy capture. Integrated multi-omics, microbial community, and electrochemical analyses showed that the continuous conductive network formed between electroactive microorganisms and methanogens via e-pili was key to the conversion of kinetic energy into electrical potential through electromagnetic processes. The induced potential not only enhanced the electrochemical activity and conductivity of microbial aggregates but also stimulated respiratory electron transfer in electroactive microorganisms and activated energy-conserving electron bifurcation in methanogens. Energy, economic, and carbon footprint analyses showed that kinetic energy recovery increased net energy recovery by 226%, reduced greenhouse gas emissions by 25%, and improved economic returns. Our work establishes a direct pathway to convert microbial motion into biochemical energy, advancing sustainable resource recovery from wastewater.