|Angenent, Lars - WASH UNIV, ST. LOUIS|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 11, 2008
Publication Date: N/A
Technical Abstract: A binary culture of Lactococcus lactis and Shewanella oneidensis was studied for an efficient conversion of glucose into electricity in a continuously-operated chemostatic electrochemical reactor. The homolactic fermentation bacterium L. lactis fermented glucose almost exclusively to lactate – the favorite electron donor for the electricigen S. oneidensis. Sugars cannot be utilized directly as an electron donor under microbial fuel cell (MFC) conditions by S. oneidensis. L. lactis alone showed no electrochemical activity, while the maximum obtained current density for S. oneidensis in a pure culture in lactate based medium was about 12 uA/cm**2, which confirms literature reports about this microorganism. However, in the binary culture with glucose as primary fuel, the current density increased by 140% to about 27 uA/cm**2. The study was followed using electrochemical, HPLC-analytical, and electron microscopic techniques. The examination of the metabolic interactions between two defined species of microorganisms eventually will help to understand the complex foodweb among mixed bacterial communities in MFCs treating complex organic compounds.