Artificial photosynthesis can produce food without sunshine

For millions of years, photosynthesis has developed within plants to convert water, carbon dioxide, and solar energy into plant biomass and the meals humans consume. However, this mechanism is incredibly inefficient, as just 1% of the energy from sunlight actually reaches the plant. By adopting artificial photosynthesis, researchers from the Universities of Delaware and Riverside have discovered a means to produce food without of the requirement for biological photosynthesis.

The study, which was published in the journal Nature Food, used a two-step electrocatalytic process to transform carbon dioxide, energy, and water into acetate, which is the chemical form of vinegar's primary ingredient. Then, in the dark, organisms that produce food use acetate. This hybrid organic-inorganic system might boost the conversion efficiency of sunlight into food, up to 18 times more efficient for some crops, when combined with solar panels to create the electricity to fuel the electrocatalysis.

According to corresponding author Robert Jinkerson, an assistant professor of chemical and environmental engineering at UC Riverside, "with our approach we sought to identify a new way of producing food that could break through the limits imposed by biological photosynthesis."

The output of the electrolyzer was tuned to assist the growth of food-producing organisms in order to unite all the parts of the system. Electrolyzers are machines that utilize electricity to transform unusable chemicals and products, such carbon dioxide, into basic resources. The greatest amounts of acetate ever generated in an electrolyzer to date were achieved by increasing the amount of acetate produced while lowering the amount of salt utilized.

"Using a state-of-the-art two-step tandem CO2 electrolysis setup developed in our laboratory, we were able to achieve a high selectivity towards acetate that cannot be accessed through conventional CO2 electrolysis routes," stated corresponding author Feng Jiao of the University of Delaware.

Experiments revealed that a variety of food-producing species, including green algae, yeast, and fungal mycelium that produces mushrooms, can be grown in the dark directly on the acetate-rich electrolyzer output. With this method, producing algae is about four times more energy-efficient than growing it photosynthesis. Production of yeast uses roughly 18 times less energy than conventional methods, which commonly use sugar from corn.

"We were able to cultivate creatures that could produce food without the assistance of biological photosynthesis. These creatures are often grown on plant-based sugars or petroleum-based inputs, which are byproducts of biological photosynthesis that occurred millions of years ago. Compared to food production that depends on biological photosynthesis, this technique is a more effective way to convert solar energy into food, according to Elizabeth Hann, a PhD candidate at the Jinkerson Lab and co-lead author of the paper.

It was also looked at if this technique might be used to raise crops. When grown in the dark, cowpea, tomato, tobacco, rice, canola, and green pea were all able to use carbon from acetate.

We discovered that a variety of plants could use the acetate we gave to create the essential molecules a creature needs to develop and flourish. "We may be able to grow crops with acetate as an additional energy source to boost crop yields with some breeding and engineering that we are currently working on," said Marcus Harland-Dunaway, a PhD candidate at the Jinkerson Lab and co-lead author of the study.

Artificial photosynthesis opens the door to endless options for growing food under the increasingly challenging conditions imposed by anthropogenic climate change by releasing agriculture from total dependency on the light. If crops for people and animals grew in less resource-intensive, regulated conditions, drought, floods, and decreased land availability would be less of a danger to global food security. Additionally, crops might be cultivated in urban areas and other regions that are now unsuited for agriculture, even providing nourishment for future space travelers.

It may be possible to change the way humans are fed by using artificial photosynthesis techniques. As food production becomes more efficient, less land is required, reducing the environmental effect of agriculture. Additionally, the improved energy efficiency might help feed more crew members while using less inputs for agriculture in non-traditional areas, like as space, according to Jinkerson.

This method of food production was entered into the NASA Deep Space Food Challenge and won Phase I. The Deep Space Food Challenge is an international competition where teams compete for cash awards to develop unique and game-changing food technologies that use few inputs and provide the most safe, nourishing, and appetizing meals possible for extended space journeys.

How much simpler would it be for future Martians if enormous boats could produce tomato plants in the dark on Mars in the future? stated co-author and head of the UC Riverside Plant Transformation Research Center Martha Orozco-Cárdenas.

The study also included contributions from Sean Overa, Dang Le, and Andres Narvaez. You can see the open-access article, "A hybrid inorganic-biological artificial photosynthesis system for energy-efficient food production," here.

The Foundation for Food and Agriculture Research (FFAR), the Link Foundation, the National Science Foundation of the United States, the U.S. Department of Energy, and the Translational Research Institute for Space Health (TRISH) under NASA (NNX16AO69A) all provided funding for the study. The writers alone are responsible for the publication's content, which does not necessarily reflect the Foundation for Food and Agriculture Research's official positions.