This research aimed at evaluating the effect of inoculum type and the application of Ru-x-MoySez as a cathode catalyst on the treatment and bioelectricity production of a microbial fuel cell (MFC) fed with a municipal leachate. The inocula assayed were a plain sulphate-reducing inoculum (In-SR), an enrichment in Mn(IV)-reducing bacteria (In-E-Mn(IV)), and two enrichments in Fe(III)-reducing bacteria, namely, In-EMn(III)-S and In-EFe(III)-SR. In the batch experiments where the cells were operated with the faces connected in parallel and loaded with an external resistance of 100 Omega, enriched inocula had a significant, positive effect of cell performance. The average volumetric powers PV-ave observed ranged from 2146 (In-SR) to 13 304 mW/m(3) (In-EFe(III)-S). The highest value of PV-ave achieved in our work was about 30% of that of commercial anaerobic digestion of wastes. Application of inocula enriched in Fe(III) and Mn (IV)-reducing bacteria significantly improved the performance of cells that used RuxMoySez as a cathodic catalyst for the oxygen reduction reaction. Copyright (c) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.