Bidirectional microbial electron transfer: Switching an acetate oxidizing biofilm to nitrate reducing conditions

Biosensors & Bioelectronics
Narcís PousSebastià Puig

Abstract

Up to date a few electroactive bacteria embedded in biofilms are described to catalyze both anodic and cathodic reactions in bioelectrochemical systems (i.e. bidirectional electron transfer). How these bacteria transfer electrons to or from the electrode is still uncertain. In this study the extracellular electron transfer mechanism of bacteria within an electroactive biofilm was investigated by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). First, a mature anodic electroactive biofilm was developed from an activated sludge sample (inoculum), acetate as electron donor and a poised electrode (+397mV vs. SHE). Later, this biofilm was "switched" to biocathodic conditions by feeding it with a medium containing nitrates and poising the electrode at -303mV vs. SHE. The electrochemical characterization indicated that both, acetate oxidation and nitrate reduction took place at a similar formal potential of -175±05 and -175±34mV vs. SHE, respectively. The biofilm was predominantly composed by Geobacter sp. at both experimental conditions. Taken together, the results indicated that both processes could be catalyzed by using the same electron conduit, and most likely by the same bacterial consortium. Hence, this s...Continue Reading

References

Mar 31, 2009·Bioelectrochemistry·Vincent FourmondChristophe Léger
Jan 27, 2012·Chemistry, an Asian Journal·Falk Harnisch, Stefano Freguia
Jan 23, 2015·Chemical Communications : Chem Comm·R GaniguéJ Colprim

❮ Previous
Next ❯

Citations

Mar 28, 2016·Biosensors & Bioelectronics·Erhan AtciHaluk Beyenal
Mar 21, 2017·Biosensors & Bioelectronics·Yong JiangXia Huang
Nov 3, 2021·Environmental Science & Technology·Xiaofei WangKorneel Rabaey

❮ Previous
Next ❯

Related Concepts

Related Feeds

Biofilm & Infectious Disease

Biofilm formation is a key virulence factor for a wide range of microorganisms that cause chronic infections.Here is the latest research on biofilm and infectious diseases.

Biofilms

Biofilms are adherent bacterial communities embedded in a polymer matrix and can cause persistent human infections that are highly resistant to antibiotics. Discover the latest research on Biofilms here.