Organic chemistry

Enzyme

Bacteria

Metabolic engineering

Biology

Gene

Biophysics

Photosynthesis

Chemistry

Cyanobacteria

Heterologous

Photosynthetic capacity

Genetics

Biochemistry

Redox

Photosystem II

Proceedings of the National Academy of Sciences

Significance Cyanobacteria have been increasingly explored as a biotechnological platform, although their economic feasibility relies in part on the capacity to maximize their photosynthetic, solar-to-biomass energy conversion efficiency. Here we show that cyanobacterial photosynthetic capacity can be increased by diverting cellular resources toward heterologous, energy-storing metabolic pathways and by reducing electron flow to photoprotective, but energy-dissipating, oxygen reduction reactions. We further show that these heterologous sinks can partially contribute to photosystem I (PSI) oxidation, suggesting an engineering strategy to improve both energy storage capacity and robustness by selective diversion of excess photosynthetic capacity to productive processes.

Improved photosynthetic capacity and photosystem I oxidation via heterologous metabolism engineering in cyanobacteria