Electrochemical performance and microbial community profiles in microbial fuel cells in relation to electron transfer mechanisms
Uría Moltó, Naroa (Universitat Autònoma de Barcelona. Departament de Genètica i de Microbiologia)
Ferrera, Isabel (Institut de Ciències del Mar. Departament de Biologia Marina i Oceanografia)
Mas Gordi, Jordi (Universitat Autònoma de Barcelona. Departament de Genètica i de Microbiologia)

Fecha:	2017
Resumen:	Background: Microbial fuel cells (MFCs) operating with complex microbial communities have been extensively reported in the past, and are commonly used in applications such as wastewater treatment, bioremediation or in-situ powering of environmental sensors. However, our knowledge on how the composition of the microbial community and the different types of electron transfer to the anode affect the performance of these bioelectrochemical systems is far from complete. To fill this gap of knowledge, we designed a set of three MFCs with different constrains limiting direct and mediated electron transfer to the anode. Results: The results obtained indicate that MFCs with a naked anode on which a biofilm was allowed unrestricted development (MFC-A) had the most diverse archaeal and bacterial community, and offered the best performance. In this MFC both, direct and mediated electron transfer, occurred simultaneously, but direct electron transfer was the predominant mechanism. Microbial fuel cells in which the anode was enclosed in a dialysis membrane and biofilm was not allowed to develop (MFC-D), had a much lower power output (about 60% lower), and a prevalence of dissolved redox species that acted as putative electron shuttles. In the anolyte of this MFC, Arcobacter and Methanosaeta were the prevalent bacteria and archaea respectively. In the third MFC, in which the anode had been covered by a cation selective nafion membrane (MFC-N), power output decreased a further 5% (95% less than MFC-A). In this MFC, conventional organic electron shuttles could not operate and the low power output obtained was presumably attributed to fermentation end-products produced by some of the organisms present in the anolyte, probably Pseudomonas or Methanosaeta. Conclusion: Electron transfer mechanisms have an impact on the development of different microbial communities and in turn on MFC performance. Although a stable current was achieved in all cases, direct electron transfer MFC showed the best performance concluding that biofilms are the major contributors to current production in MFCs. Characterization of the complex microbial assemblages in these systems may help us to unveil new electrogenic microorganisms and improve our understanding on their role to the functioning of MFCs.
Ayudas:	Ministerio de Economía y Competitividad RTC-2016-5766-2 Ministerio de Economía y Competitividad CTQ2014-54553-C3-2-R Ministerio de Economía y Competitividad CTQ2014-61809-EXP
Derechos:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Microbial fuel cell ; Electrogenic bacteria ; Electron transfer ; Pyrosequencing
Publicado en:	BMC Microbiology, Vol. 17 (October 2017) , art. 208, ISSN 1471-2180

DOI: 10.1186/s12866-017-1115-2
PMID: 29047333

12 p, 1.2 MB

El registro aparece en las colecciones:
Artículos > Artículos de investigación
Artículos > Artículos publicados