Crystallographic orientation and electrode nature are key factors for electric current generation by Geobacter sulfurreducens.

MAESTRO, BEATRÍZ; ORTÍZ, JUAN MANUEL; SCHROTT, GERMÁN DAVID; BUSALMEN, JUAN PABLO; CLIMENT, VICTOR; FELIU, JUAN MIGUEL

BIOELECTROCHEMISTRY

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2014 vol. 98 p. 11 - 19

1567-5394

We have investigated the influence of electrode material and crystallographic structure on electron transfer and biofilm formation ofGeobacter sulfurreducens. Single-crystal gold?Au(110), Au(111), Au(210)?and platinum? Pt(100), Pt(110), Pt(111), Pt(210)?electrodes were tested and compared to graphite rods.G. sulfurreducenselectrochemically interacts with all these materials with different attachment kinetics andfinal current  production, although redox species involved in the electron transfer to the anode are virtually the same in all cases. Initial bacterial colonization was fastest on graphite up to the monolayer level, whereas gold electrodes led to higherfinal current densities. Crystal geometry was shown to have an important influence, with Au(210) sustaining a currentdensity of up to 1442 ± 101μAcm −2 at the steady state, over Au(111) with 961 ± 94μAcm−2 and Au(110) with 944 ± 89μAcm−2 . On the other hand, the platinum electrodes displayed the lowest performances, including Pt(210). Our results indicate that both crystal geometry and electrode material are key parameters for the efficient interaction of bacteria with the substrate and should be considered for the design of novel materials and microbial devices to optimize energy production.