Research Article | Applied and Environmental Science Keren Yanuka-Golub, Vadim Dubinsky, Elisa Korenblum, Leah Reshef, Maya Ofek-Lalzar, Judith Rishpon, Uri Gophna María Mercedes Zambrano, Editor DOI: 10.1128/mBio.03629-20 ABSTRACT Microbial fuel cells (MFCs) generate energy while aiding the biodegradation of waste through the activity of an electroactive mixed biofilm. Metabolic cooperation is essential for MFCs’ efficiency, especially during early colonization.