Scientists at UC Riverside and the University of Delaware have devised a way to grow plants in complete darkness and create food plants in the dark using “artificial photosynthesis.” The researchers grew plants in complete darkness in an “acetate” medium that replaces biological photosynthesis.
They used a two-step electrocatalytic process to convert carbon dioxide, electricity and water into acetate. Food-producing plants then consumed this acetate to grow. Interestingly, if combined with solar power panels, this system might increase the conversion efficiency of sunlight, up to 18 times more than biological photosynthesis in some foods.
The researchers used an electrolyser to convert raw materials such as carbon dioxide into acetate. Its production was optimized to support the growth of food-producing plants by increasing the amount of acetate produced and decreasing the amount of salt produced as a by-product.
According to the researchers, this resulted in some of the highest levels of acetate ever produced in an electrolyser to date. “Using a state-of-the-art two-step tandem CO2 electrolysis setup developed in our lab, we were able to achieve high selectivity towards acetate that cannot be accessed via conventional CO2 electrolysis routes,” said the author. correspondent Feng Jiao of the University of Delaware in a press release.
The plants grow in complete darkness in the acetate medium that replaces biological photosynthesis. (Image credit: UC Riverside)
In experiments, the scientists showed that this technology might be used to grow a wide variety of food-producing organisms in the dark, including green algae, yeast, and mycelia of fungus-producing fungi. According to the research article on the study published in Nature Food, producing algae with this technology is four times more energy efficient than growing them with photosynthesis. The peer-reviewed article also says that yeast production is 18 times more energy efficient than the way it is normally grown with sugar extracted from corn.
The researchers also tested the potential of using this technology to grow cowpeas, tomatoes, tobacco, rice, canola and green peas. All plants were able to utilize the carbon from the acetate medium when grown in the dark.
By eliminating reliance on the sun, artificial photosynthesis opens up possibilities for growing food in the harsh conditions we might see in the future due to climate change. Droughts, floods, and reduced land availability would potentially be less of a threat to global food security if crops might be grown in such controlled and efficient environments.
