Structural and electrochemical characterization of G. sulfurreducens biofilms during growth on transparent electrodes

LUCIANA ROBUSCHI; GERMÁN DAVID SCHROTT; PABLO SEBASTIÁN BONANNI; JUAN PABLO BUSALMEN

Congreso; Electron transfer at the microbe-mineral interface; 2012

An experimental set up has been developed that allows the growth of anaerobic biofilm in electrogenic conditions and the simultaneous structural analysis by phase contrast microscopy. In this work we present experimental data on the development of Geobacter sulfurreducens biofilm in continuous culture using this new set up. Growth related parameters as current production, biofilm thickness and volumetric cell fraction (VC) have been measured in situ and in vivo using both, polarized ITO or gold thin film electrodes. Optical sectioning of biofilms grown on both materials evidenced an open structure with cell clusters covering a maximum of 20-25% of the electrode area at the surface level. The mean steady-state thickness of biofilms was surprisingly high at about 300µm and 200µm on ITO and gold, respectively; opposing the trend observed in the production of current, which was typically about 3.5A/m2 and 5A/m2 on ITO and gold, respectively.