Anaerobic methanotrophic archaea are key components of the biological methane filter, but progress in understanding their physiology has been limited by the lack of axenic cultures. This study establishes near-axenic electrode-grown cultures of a freshwater anaerobic methanotroph, proposed as Candidatus Methanoperedens vercellensis, and characterizes its physiology, genome, electron transfer properties, and proteins using shotgun proteomics.