This paper describes the active oxygenation performed by photosynthetic organisms in the cathode of a two-chamber Microbial Fuel Cell system. The algal biomass supplied dissolved oxygen to the cathodic oxygen reduction reaction (ORR) in a sustainable manner through the recirculation of the catholyte connected to separate photoreactors, which acted as lagoons. Aiming towards self-sustainable applications, it has been demonstrated that catholyte recirculation could be facilitated by the MFC stack itself when a dc impeller pump was periodically powered by the electricity generated from these same MFCs. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.