Design and electrochemical properties of carbonized pure bacteria electrode for supercapacitor

•Electrodes were prepared from different concentration of Gram-negative bacteria.•The carbonized bacteria electrodes showed a capacitance of 37F∙g−1 at 1 A∙g−1.•These results can prove electrochemical properties of the pure bacteria for energy storage devices.•It is possible to suggest more fundamental characteristics in terms of bacteria doped composites.