This study is focused on electrical energy generation in a double-compartment microbial fuel cell. Carbon felt impregnated with multi-walled carbon nanotubes was used as an anode, which contained gold nanoparticles and Shewanella spp. grown under aerobic conditions was used as a biocatalyst. The electrodes, used before and after biofilm growth, were characterized by scanning electron microscopy and cyclic voltammetry. The results revealed the formation of Shewanella spp. colonies on the electrode surface and electrochemical activity under aerobic and anaerobic conditions. During biofilm growth in Luria Bertani medium, a stabilized average power density of 281 mW m− 2 was recorded. Subsequently, the cell reached a maximum current density of 0.11 mA cm− 2 after 72 h of operation and a coulombic efficiency of 65% under anaerobic conditions.