초록
<P><B>Abstract</B></P> <P>Here we have developed an electrochemical-biological hybrid system to fix CO<SUB>2</SUB>. Natural biological CO<SUB>2</SUB> fixation processes are relatively slow. To increase the speed of fixation we applied electrocatalysts to reduce CO<SUB>2</SUB> to formate. We chose a user-friendly organism, <I>Escherichia coli</I>, as host. Overall, the newly constructed CO<SUB>2</SUB> and formate fixation pathway converts two formate and one CO<SUB>2</SUB> to one pyruvate via glycine and <SMALL>L</SMALL>-serine in <I>E. coli</I>. First, one formate and one CO<SUB>2</SUB> are converted to one glycine. Second, <SMALL>L</SMALL>-serine is produced from one glycine and one formate. Lastly, <SMALL>L</SMALL>-serine is converted to pyruvate. <I>E. coli</I>'s genetic tractability allowed us to balance various parameters of the pathway. The carbon flux of the pathway was sufficient to compensate <SMALL>L</SMALL>-serine auxotrophy in the strain. In total, we integrated both electrocatalysis and biological systems into a single pot to support <I>E. coli</I> growth with CO<SUB>2</SUB> and electricity. Results show promise for using this hybrid system for chemical production from CO<SUB>2</SUB> and electricity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Carbon fixation by combining biological catalysis and electrocatalysis. </LI> <LI> A RuBisCO-independent CO2 fixation pathway was constructed. </LI> <LI> The pathway converts two formate and one CO2 to one pyruvate in <I>E. coli</I>. </LI> </UL> </P>