关键词: Pseudomonas aeruginosa BTE-1, 生物膜, 电化学催化

Abstract: The aim of the present study is to investigate the electrocatalytic activity of electricity-producing Pseudomonas aeruginosa BTE-1 strain under anaerobic conditions. Pseudomonas aeruginosa BTE-1 was inoculated into anaerobic three-electrode electrochemical cells, and the electrocatalytic activity was measured at poised potentials. HPLC and cyclic voltammetry were used to detect potential electron mediators in solutions. Experimental results showed that no detectable pyocyanine was excreted by P. aeruginosa BTE-1 strain in the anaerobic electrochemcial cells, and P. aeruginosa BTE-1 exhibited direct electrocatalytic activity through the formation of biofilm on the electrode surface which was induced by the electron transfer from the cells of P. aeruginosa BTE-1 to the electrode at poised potentials. Suitable potential for biofilm formation was found to be 0.2 V (vs. SCE), and more positive potentials would lead to a potential harm to P. aeruginosa BTE-1 cells. At room temperature, the electrocatalytic activity of the P. aeruginosa BTE-1 biofilm could be enhanced by increasing temperature, however, the temperatures higher than 60 °C reduced the electrocatalytic activity of the biofilms quickly. Cyclic voltammetry analysis indicated that P. aeruginosa BTE-1 biofilms formed under anaerobic conditions exhibited an electrochemical catalytic wave in the potential range of -0.4 V to -0.2 V (vs. SCE), similar to that observed with a typical electricity-generating strain, Geobacter sulfurreducens. Organic substrates, such as compounds in yeast and glucose, could be oxidized through the catalysis of P. aeruginosa BTE-1 biofilms, whereas acetate could not be catalyzed to oxidize.

Key words: Pseudomonas aeruginosa BTE-1; , biofilm, electrocatalysis