Enrichment of microbial consortium in exoelectrogenic bacteria for its use as biocatalyst in microbial fuel cells

Abstract

The strong reliance on fossil fuels, as well as its polluting power, have driven the search for alternative energy-generating sources and technologies. Simultaneously to this scenario, industrial economic activities generate by-products, waste and polluting effluents which, if not properly treated, pose a threat to the environment in general. Thus, great efforts have been devoted to the development of technologies that add value to waste and effluents through their transformation into bioproducts and/or bioenergy. In this context, Microbial Fuel Cells (MFCs) represent innovative technologies that can generate electrical energy from the oxidation of compounds contained in effluents and wastes, promoting their bioremediation. MFCs are bioelectrochemical systems in which exoelectrogenic microorganisms work as biocatalysts growing on the anode by supplying the electrons from that oxidation to an external circuit connected to the cathode in which the electrons are accepted. Despite the great popularity that has been gaining this area of research, there are still many difficulties and questions about the current models. Among these, a better understanding of the diversity, ecology and functioning of the microbial consortia responsible for the electroactivity at the anode is needed. The present project aims, therefore, to construct MFCs using a microbial consortium obtained in Brazilian territory as inoculum. This inoculum will be cultivated and enriched in different synthetic media, in order to simulate the composition of some polluting effluents, for its later use as biocatalyst in MFCs. At each stage, (in the inoculum, enrichment in medium and enrichment in the MFC) the composition, and dynamics of the participating consortium in the generation of electricity will be analysed by qualitative PCR. For this purpose, primers related to the main groups of energy-generating bacteria will be employed. This study will allow a better understanding, control and reproducibility of the consortia, counting on approaches thought in a microbiological and ecological bias.