Fermentation

Engineering

Physical chemistry

Electrolysis

Electrode

Organic chemistry

Enzyme

Photosynthesis

Biochemical engineering

Chemistry

Renewable energy

Ecology

Synthetic biology

Carbon fixation

Raw material

Acetic acid

Yeast

Pulp and paper industry

Biochemistry

Metabolic engineering

Electrolyte

Computational biology

Biology

Nature Catalysis

Upcycling of carbon dioxide (CO2) into value-added products represents a substantially untapped opportunity to tackle environmental issues and achieve a circular economy. Compared with easily available C1/C2 products, nevertheless, efficient and sustainable synthesis of energy-rich long-chain compounds from CO2 still remains a grand challenge. Here we describe a hybrid electro-biosystem, coupling spatially separate CO2 electrolysis with yeast fermentation, that efficiently converts CO2 to glucose with a high yield. We employ a nanostructured copper catalyst that can stably catalyse pure acetic acid production with a solid-electrolyte reactor. We then genetically engineer Saccharomyces cerevisiae to produce glucose in vitro from electro-generated acetic acid by deleting all defined hexokinase genes and overexpression of heterologous glucose-1-phosphatase. In addition, we showcase that the proposed platform can be easily extended to produce other products like fatty acids using CO2 as the carbon source. These results illuminate the tantalizing possibility of a renewable-electricity-driven manufacturing industry.                                                                  Integrated electro-biocatalytic systems based on immobilization have been limited by low maximum current density. Here, the authors present spatially separated electrocatalytic CO2 fixation to acetic acid with high activity, as feedstock for fermentation by genetically engineered yeast to produce complex bioproducts including glucose and fatty acids.

Upcycling CO2 into energy-rich long-chain compounds via electrochemical and metabolic engineering