Microbial fuels cells (MFCs) are bio-electrochemical transducers that generate energy from the metabolism of electro-active microorganisms. The organism Physarum polycephalum is a slime mould, which has demonstrated many novel and interesting properties in the field of unconventional computation, such as route mapping between nutrient sources, maze solving and nutrient balancing. It is a motile, photosensitive and oxygen-consuming organism, and is known to be symbiotic with some, and antagonistic with other microbial species. In the context of artificial life, the slime mould would provide a biological mechanism (along with the microbial community) for controlling the performance and behaviour of artificial systems (MFCs, robots). In the experiments it was found that P. polycephalum did not generate significant amounts of power when inoculated in the anode. However, when P. polycephalum was introduced in the cathode of MFCs, a statistically significant difference in power output was observed.