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.

Graphene Facilitates Biomethane Production from Protein-Derived Glycine in Anaerobic Digestion

“…This further implies the possibility of DIET between fermentative bacteria and methanogenic archaea. Sedimentibacter has also been identified in the core community for microbial fuel cell systems fed with swine manure, due to their exoelectrogenic role with high power generation capability ( Vilajeliu-Pons et al., 2016 ).…”

A study of microbial communities on terracotta separator and on biocathode of air breathing microbial fuel cells

“…For example, in swine wastewater treating MFC was reported the presence of Bacillus, Corynebacterium, Citrobacter, Staphylococcus, Micrococcus and Pseudomonas, Lactobacillus, Escherichia coli, Aspergillus, and Rhizopus genera [50]. In another study [51], in MFC treating swine manure, the relative abundance of Turicibacter, Alkaliphilus sp. and Bacteroidetes were significantly higher in the two MFC compared to the raw swine manure samples, suggested an implication of these bacteria in electrogenesis.…”

Microbial fuel cell: a prospective sustainable solution for energy and environmental crisis

“…Hence, this emerging green technology could be an intensive alternative to reduce the burden of increased energy crisis and meet the societal needs. 4 As it is well known that most conventional wastewater treatment technology is not as efficient to remove the substantial amount of pollutants from grey water. 5 Moreover, these adopts expensive technologies employing sophisticated instruments, infrastructures and occupies huge land area.…”