Effects of electrode size on the power generation of the microbial fuel cell by Saccharomyces cerevisiae

Microbial fuel cells (MFC) are technologies in which microorganisms directly convert organic compounds (sugars, alcohols, effluents) into electricity. In this paper, yeast Saccharomyces cerevisiae is used in microbial fuel cells as a microorganism to produce bioelectricity. First, electron production is simulated using a genome-scale metabolic (GEM) model of the Saccharomyces cerevisiae genome-scale. The GEM model is used to predict the metabolic fluxes for microbial cells. Then, two small and large scale electrodes with 1.5 x 1.5 x 2 cm(3) and 2 x 2 x 2 cm(3) (4.5 ml and 8 ml) sizes were made and the effect of electrode size on power generation is investigated. Also, to increase the electrical conductivity, carbon/graphite is coated on the electrodes by pyrolysis spray. By changing the size of the electrode in the microbial fuel cell, the current density and the power output level were investigated. The results showed that, due to the reduction of losses in the activation region in the polarization diagram significantly, the density of electric current and the power output level in the microbial fuel cell of a small scale is higher than the large scale. Therefore, by reducing the size of the electrode in the microbial fuel cell, the production of electric current intensity and power output level increases.

Automated summary

Microbial fuel cells (MFC) use microorganisms to convert organic compounds into electricity. This study focused on using the yeast Saccharomyces cerevisiae in MFCs and investigated the effect of electrode size on power generation. Results showed that smaller electrodes in MFCs can lead to higher current density and power output levels.