Application of some selected yeasts isolates in bioelectricity generation using Microbial Fuel Cell (MFC)

Abstract

Power supply has remained a challeng issue in developing coutries. The aim of this study was to evaluate the potentials of selected yeast species for bioelectricity generation. Different yeast species were isolated from cassava wastewater, whey wastewater, human urine, and rabbit dung using the spread plate method. These isolates were identified using analytical profile index (API). Results obtained revealed the identity of the isolated yeast species as Candida famata, Candida hellenical. Candida tropicalis and Saccharomyces cerevisia (using API method).The isolated yeast species were used singly, and as a consortium for bioelectricity generation, and yeast in continuous mode. The same wastes as used for the isolation process were evaluated as possible substrates for the generation of bioelectricity. Out of the four wastes used, cassava processing wastewater gave the  highest bioelectricity potential and was subsequently used as substrate for further study. Saccharomyces cerevisiae elicited the highest electricity generation when the four yeast species were used singly (1.08V). A consortium of the four isolates elicited a synergis effect, generating 1.57V of voltage. Stacking of the Microbial Fuel Cell(MFC) components improved voltage to 2.4V due to its lower internal resistance within the stacked materials. It is apparent from the results obtained in this study that when properly harnessed, microbial fuel cells (MFCs) technology could serve as alternate source of renewable energy.

Keywords: Microbial fuel cells, Waste, yeasts, Salt- Bridge, Nafion117.