Electron Uptake from Solid Electrodes Regulates the More Efficient Conversion of CO2 to Polyhydroxybutyrate with Rhodobacter Spaeroides

Abstract

The recent climate crisis has accelerated studies on mitigating the atmospheric CO2 level. Microbial electrosynthesis (MES) is highlighted as a promising strategy for CO2 conversion to useful chemicals. This study examined electrode-driven polyhydroxybutyrate (PHB) production from CO2 in Rhodobacter sphaeroides. The electron uptake and regulation of metabolic pathways differed in electrode-associated and suspended R. sphaeroides cells. The electrode-associated cells produced PHB at concentrations reaching 23.50 ± 2.8% of the dry cell weight (DCW). These results reveal a means for CO2 upcycling to polymeric substances and provide novel insights into the genetic regulation of electrode-associated cells in MES.