DUGi

External resistances applied to MFC affect core microbiome and swine manure treatment efficiencies

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@2072@@267559

Microbial fuel cells (MFCs) can be designed to combine water treatment with concomitantelectricity production. Animal manure treatment has been poorly explored using MFCs, andits implementation at full-scale primarily relies on the bacterial distribution and activity withinthe treatment cell. This study reports the bacterial community changes at four positionswithin the anode of two almost identically operated MFCs fed swine manure. Changes inthe microbiome structure are described according to the MFC fluid dynamics and the applicationof a maximum power point tracking system (MPPT) compared to a fixed resistancesystem (Ref-MFC). Both external resistance and cell hydrodynamics are thought to heavilyinfluence MFC performance. The microbiome was characterised both quantitatively(qPCR) and qualitatively (454-pyrosequencing) by targeting bacterial 16S rRNA genes.The diversity of the microbial community in the MFC biofilm was reduced and differed fromthe influent swine manure. The adopted electric condition (MPPT vs fixed resistance)was more relevant than the fluid dynamics in shaping the MFC microbiome. MPPT controlpositively affected bacterial abundance and promoted the selection of putatively exoelectrogenicbacteria in the MFC core microbiome (Sedimentibacter sp. and gammaproteobacteria).These differences in the microbiome may be responsible for the two-fold increase inpower production achieved by the MPPT-MFC compared to the Ref-MFC

This research was financially supported by the Spanish Government (CTQ2014-53718-R) and the Catalan Government (2014 FI-B 00093)

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