Performance of a yeast-mediated biological fuel cell.

Saccharomyces cerevisiae present in common Baker's yeast was used in a microbial fuel cell in which glucose was the carbon source. Methylene blue was used as the electronophore in the anode compartment, while potassium ferricyanide and methylene blue were tested as electron acceptors in the cathode compartment. Microbes in a mediator-free environment were used as the control. The experiment was performed in both open and closed circuit configurations under different loads ranging from 100 kOmega to 400Omega. The eukaryotic S. cerevisiae-based fuel cell showed improved performance when methylene blue and ferricyanide were used as electron mediators, rendering a maximum power generation of 146.71+/-7.7 mW/m(3). The fuel cell generated a maximum open circuit voltage of 383.6+/-1.5 mV and recorded a maximum efficiency of 28+/-1.8 % under 100 kOmega of external load.