Converting CO2 to single-cell protein via an integrated electrocatalytic-biosynthetic system

Abstract

Boosting CO2 biotransformation by renewable electrical energy provides a prospective avenue to reform the biomanufacturing paradigm and achieve a circular carbon economy. However, mismatches between electrocatalytic and biosynthetic modules lead to poor efficiency. Herein, we design an integrated electro-driven CO2-single cell protein (SCP) transformation system, via coupling an electrocatalytic CO2 reduction to formate module with a formate assimilation module. A Cu/Cu2O electrocatalyst has been rationally designed with excellent duration stability over 100 h under −0.78 VRHE. Strain adaptability investigation and equipment upgrading are carried out to guarantee the effective integration. SCP has been accumulated to a OD600 of 4 with an exponential growth rate of 0.114 OD h−1 and electrical energy conversion efficiency of 9.2%. No risky hydrogen is needed and the produced formate is ready-to-use for biosynthesis. The elaborate construction bridges non-biological and biological carbon fixation units and offers a promising blueprint for electro-driven CO2 biotransformation and scalable bio-manufacturing.