title: External Resistances Applied to MFC Affect Core Microbiome and Swine Manure Treatment Efficiencies.
abstract: Microbial fuel cells (MFCs) can be designed to combine water treatment with concomitant electricity production. Animal manure treatment has been poorly explored using MFCs, and its implementation at full-scale primarily relies on the bacterial distribution and activity within the treatment cell. This study reports the bacterial community changes at four positions within the anode of two almost identically operated MFCs fed swine manure. Changes in the microbiome structure are described according to the MFC fluid dynamics and the application of a maximum power point tracking system (MPPT) compared to a fixed resistance system (Ref-MFC). Both external resistance and cell hydrodynamics are thought to heavily influence 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 from the influent swine manure. The adopted electric condition (MPPT vs fixed resistance) was more relevant than the fluid dynamics in shaping the MFC microbiome. MPPT control positively affected bacterial abundance and promoted the selection of putatively exoelectrogenic bacteria in the MFC core microbiome (Sedimentibacter sp. and gammaproteobacteria). These differences in the microbiome may be responsible for the two-fold increase in power production achieved by the MPPT-MFC compared to the Ref-MFC.
authors.affiliation: LEQUiA, Institute of the Environment, University of Girona, Girona, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Vilajeliu-Pons
authors.affiliation: Molecular Microbial Ecology Group, Institute of Aquatic Ecology, University of Girona, Girona, Spain.
authors.forename: Lluis
authors.initials: L
authors.lastname: Bañeras
authors.affiliation: LEQUiA, Institute of the Environment, University of Girona, Girona, Spain.
authors.forename: Sebastià
authors.initials: S
authors.lastname: Puig
authors.affiliation: Department of Civil Engineering and Architecture (D.I.C.Ar.), University of Pavia, Pavia, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Molognoni
authors.affiliation: LEQUiA, Institute of the Environment, University of Girona, Girona, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Vilà-Rovira
authors.affiliation: Molecular Microbial Ecology Group, Institute of Aquatic Ecology, University of Girona, Girona, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Hernández-Del Amo
authors.affiliation: LEQUiA, Institute of the Environment, University of Girona, Girona, Spain.
authors.forename: Maria D
authors.initials: MD
authors.lastname: Balaguer
authors.affiliation: LEQUiA, Institute of the Environment, University of Girona, Girona, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Colprim
mesh_terms: D000818:Animals; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D000068536:Bacillota / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D020563:Gammaproteobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D059014:High-Throughput Nucleotide Sequencing; D057446:Hydrodynamics; D008372:Manure / Q000382:microbiology*; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013552:Swine
chemical_list: D008372:Manure; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S