Exoelectrogenic response of Pichia fermentans influenced by mediator and reactor design.

Microbial fuel cell is one of the most convenient and cost-effective technology for producing the clean energy. This study explores the exoelectrogenic behavior of Pichia fermentans in a microbial fuel cell. Two different reactor designs (double- and single-chambered) were tested in the presence and in the absence of a mediator (methylene blue). The influence of extracellular polymeric substances in the electricity generation has also been studied. In a double-chambered setup, maximum open circuit voltages were measured as 0.602 and 0.488 V with mediator and without mediator cell, respectively, whereas maximum power densities were measured as 1.23 μWcm and 0.407 μWcm, respectively. In addition, maximum open circuit voltages were observed as 0.40 and 0.397 V in a single-chambered fuel cell with and without mediator, respectively. The maximum power density was recorded 1.64 μWcm in the presence of a mediator, whereas the same was found as 0.643 μWcm in the absence of mediator. Thus, these results indicate that P. fermentans has the ability to produce high power density under microaerophilic conditions with mediator in a single-chambered membrane less setup.