Carbon dioxide (CO2) emitted by human activities can be converted into environmentally friendly bioplastic: this is thanks to a new system that combines the electrolysis of CO2, already tested in the past, with bacterial fermentation.
The first results are published in the journal of the American Academy of Sciences (PNAS) by researchers at the Korea Advanced Institute of Science and Technology in Daejeon, South Korea.
Their new biohybrid system consists of two chambers.
In the first, the electrochemical conversion of gaseous CO2 into formate takes place, thanks to tin catalysts on a gaseous diffusion electrode.
The formate thus produced then flows into the second chamber where fermentation takes place by the bacterium Cupriavidus necator, which through its metabolism transforms the formate into bacterial polyester (PHB, poly-3-hydroxybutyrate).
In early laboratory tests, the system efficiently produced 1.38 grams of PHB using a 4 square centimeter electrode with a PHB content of 83% of the dry cell weight of C. necator.
The study authors say the system can be scaled up for mass production and could be economically powered by renewable energy.
