Engineered photosynthesis and artificial chloroplasts

Engineered photosynthesis and artificial chloroplasts rewire the biological process that fixes about 120 gigatonnes of carbon from CO2 each year. Natural photosynthesis converts only about 1-2% of incident sunlight into biomass in most C3 crops, while C4 plants reach roughly 4-6%; the field pushes that ceiling by engineering faster carbon fixation and by building light-driven CO2-fixation systems outside the living cell. Living Carbon’s PagPIP1;2 overexpression raised leaf CO2 conductance, photosynthesis and biomass in poplar (Industrial Crops and Products, 2026); IRRI demonstrated C4 photosynthetic pathway fluxes in transgenic rice (bioRxiv, 2026); the CETCH cycle designed at the Max Planck Institute fixes CO2 through a new-to-nature pathway that outpaces the Calvin-Benson cycle; and a 2026 Chinese Academy of Sciences breakthrough converted CO2 and water to energy under natural sunlight.

The key directions of engineered photosynthesis and artificial chloroplasts are:

1. Enhanced photosynthesis in plants (Enhanced Photosynthesis): overexpressing CO2-conductance and carbon-storage genes to raise biomass and carbon sequestration — Living Carbon’s PagPIP1;2 and bark-storage-protein poplar.
2. C4 photosynthesis engineering (C4 Rice Engineering): installing the more efficient C4 pathway into C3 rice — IRRI’s C4 Rice Project and transgenic C4-flux rice.
3. New-to-nature CO2 fixation (CETCH Cycle): designing synthetic CO2-fixation enzymes and artificial chloroplast organelles that exceed natural rates — Max Planck Institute’s Tobias Erb group and Photosynthesis 2.0.
4. Artificial photosynthesis and bionic leaves (Artificial Photosynthesis): fully synthetic light-driven CO2-reduction and bio-electrochemical hybrids — Forschungszentrum Jülich solar fuels, Harvard’s bionic leaf and the CAS sunlight breakthrough.

Sectoral value chain#

[sunlight + CO2] ──> [engineered plant / chloroplast] ──> [fixed carbon]
                                │
                        (enzymatic / electrocatalytic)
                                │
                                ▼
[biofertilizer] <─── [recovered product] <─────┘

Value chain levels#

Cross-cutting technologies of the sector:

• Synthetic CO2-fixation cycles (CETCH Cycle): the Max Planck-designed crotonyl-CoA carboxylase pathway fixes CO2 faster than the natural Calvin-Benson cycle in a cell-free artificial chloroplast.
• PV-battery-electrochemical hybrids (PV-EC Solar Fuels): Forschungszentrum Jülich couples photovoltaic, battery buffering and CO2-reduction cells to turn sunlight and CO2 into fuels beyond the limits of photosynthesis.
• Foliar biofertilizer from the bionic leaf (Bionic-Leaf Biofertilizer): Harvard’s nanocoated nitrogen-fixing bacteria, originating in bionic-leaf research, deliver foliar nitrogen to crops (Nature Food, 2026).

The stack spans engineered genes in living plants, synthetic enzymes in cell-free organelles, and fully abiotic light-driven CO2 reduction.

1. Enhanced-photosynthesis genes (Enhanced Photosynthesis):
   • PagPIP1;2 overexpression raises leaf CO2 conductance and biomass in poplar, while bark-storage-protein co-expression promotes growth and redirects carbon — Living Carbon’s basis for field-deployed carbon-sequestering trees.
   • IRRI’s C4 Rice Project engineers C4 photosynthetic pathway fluxes into transgenic rice, aiming to lift the crop from about 1-2% toward the 4-6% efficiency of natural C4 plants.
2. Synthetic CO2-fixation cycles (CETCH Cycle):
   • the Max Planck-designed CETCH cycle uses crotonyl-CoA carboxylase and a new-to-nature enzyme network to fix CO2 faster than the Calvin-Benson cycle, hosted in cell-free artificial chloroplast organelles.
   • the agenda is framed as “Photosynthesis 2.0” — redesigning the carbon cycle with synthetic biology beyond evolution’s constraints.
3. Artificial photosynthesis and bionic leaves (Artificial Photosynthesis):
   • Forschungszentrum Jülich’s hybrid PV-battery-electrochemical systems drive CO2 reduction into solar fuels, while a 2026 CAS Institute of Botany breakthrough converted CO2 and water to energy under natural sunlight.
   • Harvard’s bionic-leaf lineage translates into nanocoated nitrogen-fixing bacteria that deliver foliar nitrogen to crops — a bio-solar nitrogen economy (Nature Food, 2026).