Interspecies synergism in electroactive biofilms: New directions for advancing and innovating microbial electrochemical technologies

• Implementation of MET is crucial for wastewater treatment and current generation, enabling addressing societal challenges. • Microbial cooperation and communication processes enhance extracellular electron transfer in electroactive biofilms. • In MET, mixed microbial communities process more complex substrates and improve extracellular electron transfer. • Synergistic interactions involve metabolite and redox mediator exchange that support electroactivity. • Understanding synergistic interactions is key to guiding the development of the next-generation MET platform.