This study investigated the ability of the bacterium Acidithiobacillus ferrooxidans to convert CO2 into organic compounds in batch culture and during electrochemical cultivation. Metabolites secreted into the culture medium were detected and analyzed by HPLC and mass spectroscopy, which revealed that pyruvic acid was one of the organic acids present in both cultures. We found that although pyruvic acid acted as a strong inhibitor for microbial growth in batch cultures, microbial CO2 fixation activity in electrochemical cultures was not significantly affected by the addition of excess pyruvic acid. Together, these findings indicate that A. ferrooxidans is a promising bioelectrocatalyst for the conversion of CO2 into extracellular organic compounds.
2012 The Electrochemical Society of Japan