2014 Volume 39 Issue 1 Pages 24-32
Microbial Electrosynthesis (MES) is an emerging category of bio-electrochemical systems to convert CO2 into commodity chemicals. In MES, electrical current is used to drive microbial production of organics (such as methane, organic acids and alcohols) from CO2. Thus, MES systems using photovoltaic cell (or other renewable sources) as the power sources can be regarded as “artificial photosynthesis systems”. Based on the mechanism of electron transfer from the electrode (cathode) to catalytic microorganisms, MES can be divided into two types, the “indirect” and “direct” MESs. In the “indirect” systems, electrons are used to biotically or abiotically reduce electron-mediator molecules (electron shuttles or electron donors), which are then used by the CO2-reducing microorganisms. In the “direct” systems, on the other hand, electrons are directly utilized to drive the metabolic process of catalytic microorganisms, which were electrically linked to the cathode (called “biocathode”). In this review, with particular focus on the biocathode-utilizing systems, current status of researches on MES is overviewed and technical considerations for implementation of the systems will be discussed.
