The demand for food is growing globally, but its production is ultimately limited by the energy conversion efficiency of photosynthesis.

Scientists have found a way to completely bypass the need for biological photosynthesis and create food independent of sunlight. by using artificial photosynthesis, something that could be used in future space missions to the Moon or Mars.

The demand for food is growing globally, but its production is ultimately limited by the energy conversion efficiency of photosynthesis. Large tracts of land are required to capture the solar energy needed to provide food for humanity.

Increasing the energy efficiency of food production (converting solar energy into biomass) would allow more food to be produced using fewer resources. The technology uses a two-step electrocatalytic process to convert carbon dioxide, electricity and water into acetate. Food-producing organisms then consume acetate in the dark to grow. The organic-inorganic hybrid system could increase the efficiency of converting sunlight into food, making it up to 18 times more efficient.

Scientists were able to grow food-producing organisms without any contribution from biological photosynthesis

Photosynthesis has evolved in plants over millions of years to convert water, carbon dioxide, and energy from sunlight into plant biomass and the food we eat. Nevertheless, this process is very inefficient, as only about 1% of the energy found in sunlight ends up in the plant. The scientists of UC Riverside and the University of Delaware have found a way to bypass the need for biological photosynthesis altogether and create food independent of sunlight by using artificial photosynthesis. The research, published in Nature Fooduses a two-step electrocatalytic process, combined with solar panels that generate electricity to power the electrocatalysis.

“With our approach, we seek to identify a new way of producing food that could break the limits normally imposed by biological photosynthesis”, explained the author Robert Jinkerson, assistant professor of chemical and environmental engineering at UC Riverside. To integrate all system components, the output of the electrolyzer was optimized to support the growth of food-producing organisms. Electrolyzers are devices that use electricity to convert raw materials like carbon dioxide into useful molecules and products. The amount of acetate produced increased while the amount of salt used decreased, resulting in the highest levels of acetate ever produced in an electrolyser to date.

Electrolyzers are devices that use electricity to convert raw materials like carbon dioxide into useful molecules and products.

Experiments demonstrated that a wide range of food-producing organisms can be grown in the dark directly at the outlet of the acetate-rich electrolyser, including green algae, yeast, and fungal mycelium that produce fungi. Producing algae with this technology is about four times more energy efficient than growing it photosynthetically. Yeast production is about 18 times more energy efficient than the way it is typically grown with sugar extracted from corn.

“We were able to grow food-producing organisms without any contribution from biological photosynthesis. Typically, these organisms are grown with plant-derived sugars or petroleum-derived inputs, which is a product of biological photosynthesis that took place millions of years ago. This technology is a more efficient method of converting solar energy into food, compared to food production that relies on biological photosynthesis.” Elizabeth Hanna doctoral student at the Jinkerson Laboratory and co-senior author of the study. The potential of using this technology to grow plants was also investigated.

Cowpeas, tomatoes, tobacco, rice, canola and peas were able to use acetate carbon when grown in the dark. “We found that a wide range of crops could take the acetate we provide and turn it into the main molecular building blocks an organism needs to grow and thrive. With some breeding and engineering that we are currently working on, we might be able to produce crops with acetate as an additional energy source to increase crop yields,” he said. Marcus Harland-Dunaway a doctoral student at the Jinkerson Laboratory and co-senior author of the study.

From fiction to reality? By freeing agriculture from total dependence on the sun, artificial photosynthesis opens the door to countless possibilities for growing food in increasingly difficult conditions.

By freeing agriculture from total dependence on the sun, artificial photosynthesis opens the door to countless possibilities for growing food in the increasingly difficult conditions imposed by anthropogenic climate change.. Droughts, floods, and reduced land availability would be less of a threat to global food security if crops for humans and animals were grown in controlled environments that require fewer resources. Crops could also be grown in cities and other areas not currently suitable for agriculture, and even provide food for future space explorers.

“The use of Artificial photosynthesis approaches to produce food could be a paradigm shift in the way we feed people. By increasing the efficiency of food production, less land is needed, reducing the impact agriculture has on the environment. And for farming in non-traditional settings, like outer space, increased energy efficiency could help feed more crew members with fewer inputs.” This approach to food production was submitted to NASA’s Deep Space Food Challenge, where it was the Phase I winner.

This is an international competition in which prizes are awarded to teams to create novel and revolutionary food technologies that require minimal inputs and maximize the production of safe, nutritious and tasty food for long-duration space missions. “Imagine one day giant ships growing tomato plants in the dark and on Mars concluded said co-author Martha Orozco-Cárdenas, director of the UC Riverside Plant Transformation Research Center.

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