Bioplastic Production from the Microbial Electrosynthesis of Acetate through CO₂Reduction

Microbial electrosynthesis (MES) is an emerging technology that uses electricity and biocatalysts to reduce CO₂and produce organic commodities. To improve the added value of MES products, we used the MES product ofRalstonia eutrophato generate polyhydroxybutyrate (PHB), a type of bioplastic. The first step was to generate a certain concentration of acetate in MES. The second step was to use acetate at the concentration produced by MES as a substrate for PHB generation byR. eutropha. Simultaneously, we compared the effects of acetate produced by double-chamber and triple-chamber MES reactors on PHB production. Lastly, 0.460 g/L PHB was produced ex situ from 5 g/L acetate in the triple-chamber MES reactor byR. eutropha. This PHB yield was the highest among all of the experimental groups. In MES, the composition and salinity of a product will affect the synthesis of PHB.