Various voltage productions by microbial fuel cells with sedimentary inocula taken from different sites in one freshwater lake

► Sedimentary inocula had strong effect on air-cathode MFC performance. ► Voltages from MFCs were significantly related to Fe(III) contents in sediments. ► Iron-oxides in sediments favored the evolution of exoelectrogenic bacteria. ► Fe(III) content in sediments was important in selecting sedimentary inocula for MFC.