Researchers at KTH Royal Institute of Technology in Sweden, led by Professor Paul Hudson, built and tested about 15,000 genetically altered versions of Rubisco, the enzyme that fixes carbon dioxide in photosynthesis. The study was published in Science Advances.
Rubisco has a well-known flaw: it sometimes reacts with oxygen instead of carbon dioxide, which wastes energy and slows plant growth. To find better versions, the team created a platform that tags each variant with a short DNA label, allowing thousands to be tracked at once in a photosynthetic bacterium.
Several variants looked promising. The two best reacted less with oxygen while keeping a good ability to use carbon dioxide, though with some losses in efficiency. The team also found that beneficial mutations often stop working when combined.
The next step is to reduce the oxygen reaction further and understand which parts of the enzyme favour carbon dioxide. Tests in plant cells and cyanobacteria continue under an EU-funded project; applying the work to crops will still require extensive testing.
