Microbial fuel cells are a type of bio-electrochemical system which can capture electrons produced by microorganisms. In this study, it is aimed to increase the electrogenic capacity of photosynthetic microbial fuel cells in a newly designed fuel cell. Rhodobacter sphaeroides, non-sulfur purple bacterium, was grown in anodic part of the fuel cells against permanganate as a cathodic electrolyte. Platine and graphite were used as the anodic and cathodic electrode, consequently. The distance between two electrodes was 1.5 cm. The concentrations of cathodic electrolyte were optimized. By the end, it is made to reach the highest anode potential (1.006 V) and electrogenic capacity (851.82 mu A) in 5 mM permanganate concentration. The internal resistance was calculated as 1170 Omega. In these conditions, the current density with 2.1 cm(2) cathodic surface is 405.63 mA/m(2). These are the highest value of electricity generation potential of R. sphaeroides within the known PMFCs. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.