Catalysis of the electrochemical reduction of oxygen by bacteria isolated from electro-active biofilms formed in seawater.
Biofilms formed in aerobic seawater on stainless steel are known to be efficient catalysts of the electrochemical reduction of oxygen. Based on their genomic analysis, seven bacterial isolates were selected and a cyclic voltammetry (CV) procedure was implemented to check their electrocatalytic activity towards oxygen reduction. All isolates exhibited close catalytic characteristics. Comparison between CVs recorded with glassy carbon and pyrolytic graphite electrodes showed that the catalytic effect was not correlated with the surface area covered by the cells. The low catalytic effect obtained with filtered isolates indicated the involvement of released redox compounds, which was confirmed by CVs performed with adsorbed iron-porphyrin. None of the isolates were able to form electro-active biofilms under constant polarization. The capacity to catalyze oxygen reduction is shown to be a widespread property among bacteria, but the property detected by CV does not necessarily confer the ability to achieve stable oxygen reduction under constant polarization.
Parot
Sandrine
S
Laboratoire de Génie Chimique CNRS-INPT, 4 allée Emile Monso BP 84234, 31030 Toulouse, France.
Vandecandelaere
Ilse
I
Cournet
Amandine
A
Délia
Marie-Line
ML
Vandamme
Peter
P
Bergé
Mathieu
M
Roques
Christine
C
Bergel
Alain
A
D000327:Adsorption; D000332:Aerobiosis; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification*; D018441:Biofilms / Q000254:growth & development*; D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D004563:Electrochemistry; D004566:Electrodes / Q000382:microbiology; D006108:Graphite / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D012623:Seawater / Q000382:microbiology; D013193:Stainless Steel / Q000737:chemistry
D013193:Stainless Steel; D002244:Carbon; D006108:Graphite; D007501:Iron; D010100:Oxygen