Researchers are working to create artificial photosynthesis to help improve the energy efficiency of food production on Earth and perhaps Mars someday. Since millions of years ago, photosynthesis in plants has evolved to convert water, carbon dioxide and solar energy into plant biomass and the food we consume.
However, this method is incredibly inefficient because only 1% of the energy from sunlight actually reaches the plant. Artificial photosynthesis was developed by researchers from the Universities of Delaware and California Riverside to completely replace the need for biological photosynthesis and enable food production without the use of sunlight.
The new study, published June 23, 2022 in the journal Nature Food, uses a two-step electrocatalytic method to convert carbon dioxide, electricity, and water, the chemical form of vinegar's main component, into acetate.
In the dark, food-producing organisms use acetate. This hybrid organic-inorganic system, when combined with solar panels to generate electricity to power the electrocatalysis, can increase the efficiency of converting sunlight into food, which is up to 18 times more efficient for certain foods.
According to corresponding author Robert Jinkerson, assistant professor in the department of chemical and environmental engineering at UC Riverside, “with our approach, we hoped to uncover a new method of producing food that could overcome the constraints imposed by biological photosynthesis.”
The output of the electrolyzer was adjusted to help the growth of food-producing organisms to assemble all parts of the system.
Electrolyzers are machines that use electricity to convert unusable chemicals and products such as carbon dioxide into basic materials.
The highest levels of acetate ever produced in an electrolyzer were achieved by increasing the amount of acetate produced while reducing the amount of salt used.
“The most advanced two-stage tandem CO in our lab,” explains Feng Jiao of the University of Delaware.2 conventional CO using the electrolysis setup2 We were able to achieve a high selectivity towards acetate, which is not accessible by electrolysis means”.
Experiments revealed that various food-producing species, including green algae, yeasts, and fungus-producing fungal mycelium, can be grown in the dark directly on the acetate-rich electrolyzer output.
Producing algae by this method is about four times more energy efficient than performing photosynthesis. Yeast production uses about 18 times less energy than traditional methods, which commonly use sugar from corn.
“We were able to grow organisms that could produce food without the aid of biological photosynthesis. These creatures are typically grown on plant-based sugars or petroleum-based inputs, which are byproducts of biological photosynthesis that occurred millions of years ago.
Compared to food. This technique, based on biological photosynthesis, is a more efficient way to convert solar energy into food, according to Elizabeth Hann, PhD candidate at Jinkerson Labs and lead author of the paper.
It was also looked at whether this technique could be used to grow crops. When grown in the dark, cowpeas, tomatoes, tobacco, rice, canola and green peas could use carbon from acetate.
We discovered that the acetate we provided can be used by various plants to create essential molecules that a living thing needs for growth and development. "With some breeding and engineering that we're currently working on, we can grow crops with acetate as an additional energy source to increase agricultural yields," said researcher Dunaway.
Artificial photosynthesis frees agriculture from total reliance on the sun, opening the door to endless options for growing food under the increasingly challenging conditions imposed by anthropogenic climate change.
If crops for humans and animals are grown in less resource-intensive, orderly conditions, drought, flooding and reduced land availability will pose less of a threat to global food security. Additionally, crops can be grown in urban areas and other areas currently unsuitable for agriculture, even providing food for future space explorers.
It may be possible to change the way people eat, using artificial photosynthesis techniques. As food production becomes more efficient, less land is needed, reducing the environmental impact of agriculture. Additionally, improved energy efficiency could help feed more crew members while using less input for agriculture in non-traditional areas such as space, according to Jinkerson.
This approach to food production was submitted to the Deep Space Food Challenge, where NASA was the winner of Phase One. The Deep Space Food Challenge is an international competition where awards are given to teams for creating new and game-changing food technologies that require minimal input and maximize safe, nutritious and delicious food outputs for long-duration space missions.
Here are the statements of Martha Cárdenas, Head of the UC Riverside Plant Transformation Research Center.
How simple would it be for future Martians if enormous ships could grow tomato plants in the dark on Mars in the future?
Reference: “A hybrid inorganic–biological artificial photosynthesis system for energy-efficient food production” by Elizabeth C. Hann, Sean Overa, Marcus Harland-Dunaway, Andrés F. Narvaez, Dang N. Le, Martha L. Orozco-Cárdenas, Feng Jiao and Robert E. Jinkerson, 23 June 2022, Nature Food.
DOI: 10.1038 / s43016-022-00530-x