Characterization of electron transfer mechanism in mediated microbial fuel cell by entrapped electron mediator in saccharomyces cerevisiae

Attributed to exponentially growing global energy demand in current scenario, microbial fuel cells (MFCs) are an attempt aimed towards achieving electric energy sustainability, using renewable resources such as the organic substrates in domestic or industrial wastewater. In our findings growing cells of common baker's yeast such as Saccharomyces cerevisiae was immobilized by inclusion techniques in cellulose acetate membrane on the surface of a graphite electrode. Immobilized cells were grown using nutrient broth while the substrate, like electron donor in MFC, was glucose. The rate of substrate consumption of the anode electrode indicated that Saccharomyces cerevisiae, also immobilised, had a huge potential to generate electrons. Our results showed that the current and voltage output of a Saccharomyces cerevisiae based MFC are directly correlated to the cells on the micro-environment of the electrode and to the presence of an electron mediator such as methylene blue (MB). Our findings suggested that reduced methylene blue was entrapped into the cells, enhancing the electron transfer on the graphite electrode as an internal mediator of the cellular metabolism, probably linked to the oxidative electron cascade.