Photosynthesis is one of nature’s most useful chemical reactions, so it’s not surprising that scientists often try to mimic it. Now, researchers from the Max Planck Institute have developed a new way to make hybrid synthetic living cells that can use photosynthesis to clear carbon dioxide from the air using solar energy.
Embedded inside the leaves of plants are tiny organelles called chloroplasts. These are the machines behind photosynthesis, absorbing light from the Sun and, by consuming water and carbon dioxide gathered by the plant, creating molecules the plant can use for energy.
And now, the Max Planck team has created artificial chloroplasts by the thousands. In this case, the goal wasn’t so much the energy output but the “side effect” of removing carbon dioxide from the air.
The researchers started by isolating thylacoids – the active parts of a plant’s photosynthesis systems – from spinach. Then, they paired these up with an artificial metabolic module called the CETCH cycle, which is made up of 18 biocatalysts that can convert carbon dioxide far more efficiently than plants can alone.
And finally, these natural and artificial components are then combined into cell-sized droplets that hold everything together. This is done using a microfluidics system that puts droplets of water into a medium that is mostly oil. Using this technique, the team says thousands of these droplets can be produced easily and quickly, tweaking the abilities of some as needed.
"We can produce thousands of identically equipped droplets or we can give specific properties to individual droplets," says Tarryn Miller, lead author of the study. "These can be controlled in time and space by light.”
In tests, the researchers found that droplets with the new design were up to 100 times faster at binding carbon dioxide than other semi-synthetic photosynthesis systems.
Other artificial and hybrid photosynthesis systems have been put to work in reducing atmospheric carbon dioxide levels, or producing energy, drugs, and fuels. The team says that the newly designed droplets could eventually tackle the same problems.
The research was published in the journal Science.
Source: Max Planck Institute
