Enhanced open-circuit voltage and power for two types of microbial fuel cells in batch experiments using Saccharomyces cerevisiae as biocatalyst

Abstract

The combined influence of iron and calcium salts can increase the voltage and power of MFC systems using Saccharomyces cerevisiae as biocatalyst, but no systematic studies were performed. To explore these incomplete understood interactions, the production of bioelectricity has been studied in two types of dual-chambered MFC systems: in small volume batch system with frit as separator and in a medium volume batch system with nafion. In both MFC experiments, CaCO3 and FeSO4 were added as supplements in a modified medium. In the MFC experiment with frit, the highest OCV (1.143 V) was recorded at about 8 h, while in the MFC experiment with nafion, the highest OCV (1.128 V) was recorded at about 132 h, values which are attributable to the above-mentioned mineral salts and exceeding the OCV value of 0.847 V reported in the literature, thus, to our knowledge, higher than any OCV ever recorded from one single MFC operated in batch mode. The power density in the MFC experiment with frit was 1.031 W m− 2, being in concordance with the best literature values. The power densities in the MFC experiment with nafion were lower but increased over time, while the high OCV values were more stable over longer time periods. Overall, the experimental data showed the potential of Saccharomyces cerevisiae in generation of bioelectricity in different MFC configurations.