“Using artificial photosynthesis approaches to produce food could be a paradigm shift for how we feed people,” one scientist points out.
Photo: Pixabay / adege
Sunlight is essential for plants, as it is through photosynthesis that they grow and thrive by converting carbon dioxide, water and sun energy into plant biomass. Or is it really essential?
Not necessarily, say U.S. scientists, who have devised a way to grow food in the dark without sunlight using artificial photosynthesis.
His method uses an electrocatalytic process by which carbon dioxide, electricity, and water are converted to acetate (a component of vinegar), which is then consumed by food-producing organisms in the dark.
Its organic-inorganic hybrid system, when connected to solar panels to power the electrocatalysis needed for the process, could increase the efficiency of converting sunlight into food up to 18 times in some cases, scientists say, which they work at the University of California Riverside and the University of Delaware.
Photosynthesis, they explain, is highly inefficient, as only about 1% of the energy found in sunlight ends up in plant matter. “With our approach we tried to identify a new way to produce food that could break the limits normally imposed by biological photosynthesis,” notes Robert Jinkerson, assistant professor of chemical and environmental engineering at UC Riverside.
“Using a state-of-the-art tandem CO2 electrolysis configuration developed in our laboratory, we were able to achieve high selectivity towards acetate which cannot be accessed by conventional CO2 electrolysis pathways,” he explains. Feng Jiao, a scientist at the University of Delaware.
Food-producing organisms that can be grown in the dark on acetate-rich electrolyzers include green algae, yeast, and mushroom-producing fungal mycelium.
“Algae production with this technology is about four times more energy efficient than growing them photosynthetically. Yeast production is about 18 times more energy efficient than how it is normally grown with sugar extracted from corn,” the scientists note.
Even common crops such as tomatoes, tobacco, rice, canola and green peas were able to extract carbon from acetate when grown in the dark.
“We found that a wide range of cultures could take the acetate we provided and incorporate it into the major molecular blocks an organism needs to grow and thrive,” says Marcus Harland-Dunaway, a doctoral student who was lead co-author of a study of findings.
“With some improvement and engineering that we are currently working on, we could grow crops with acetate as an additional energy source to increase crop yields,” the researcher adds.
Thanks to this advancement, food-producing organisms can now be grown without the need for 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,” explains Elizabeth Hann, a doctoral candidate who was another main co-author. “That [new] Technology is a more efficient method of converting solar energy into food, compared to food production that is based on biological photosynthesis. “
It is important to note that because the new method of artificial photosynthesis obviates the need for the sun, “it opens the door to innumerable possibilities for food cultivation in the increasingly difficult conditions imposed by anthropogenic climate change,” according to the scientists.
Land scarcity will be a lesser threat to global food security if crops can be grown in controlled environments that consume fewer resources without the need for sun. In addition, crops could also be grown in cities and other areas such as underground lands that have so far not been suitable for agriculture.
“Using artificial photosynthesis approaches to produce food could be a paradigm shift for how we feed people,” Jinkerson stresses.
“By increasing the efficiency of food production, less land is needed, reducing the impact that agriculture has on the environment. And for agriculture in non-traditional environments, such as outer space, increased energy efficiency could help feed more crew members with fewer inputs, ”the scientist adds.