Scientists have created an artificial photosynthesis method to grow plants without sun in a breakthrough that could lead to new ways to grow food on Earth – and possibly a day on Mars.
Over millions of years of evolution, photosynthesis developed in plants as a way to turn water, carbon dioxide and the energy of sunlight into plant biomass and the food we eat.
But researchers, including those at the University of California, Riverside, in the United States, said this natural process is inefficient, with only 1% of the energy found in sunlight ending up in the plant.
They are currently evaluating ways to produce crops such as cowpeas, tomatoes, tobacco, rice, canola and green peas that utilize carbon from acetate when grown in the dark.
“Imagine one day giant ships growing tomato plants in the dark and on Mars – how much easier would it be for future Martians?” said Martha Orozco-Cárdenas, director of the UC Riverside Plant Transformation Research Center.
A new study published in the journal Natural food last week revealed how scientists found a way to create sunlight-independent food using artificial photosynthesis.
The researchers used a two-step chemical process to convert carbon dioxide, electricity and water into acetate – a form of vinegar’s main component.
Food-producing organisms consumed acetate to grow in the dark, they said.
Using solar panels to generate electricity to fuel the chemical reaction, the scientists said the system could increase the efficiency of converting sunlight into food and make it up to 18 times more efficient for some foods.
They used electrolysers or devices that use electricity to convert raw materials like carbon dioxide into useful molecules and products.
The scientists then optimized the production of electrolysers to support the growth of food-producing organisms and integrated all components of the system.
With the new system, researchers can increase the amount of acetate while decreasing the amount of salt, leading to the highest levels of acetate the first has ever produced in an electrolyzer to date.
“With our approach, we sought to identify a new way of producing food that could break the limits normally imposed by biological photosynthesis,” said study corresponding author Robert Jinkerson of UC Riverside in a statement.
“Using a state-of-the-art two-step tandem CO2 electrolysis setup developed in our lab, we were able to achieve a high selectivity towards acetate that cannot be accessed by conventional CO2 electrolysis routes,” said Feng Jiao, another co-author. -author of the study. -author of the University of Delaware.
A wide range of food-producing organisms, including green algae, yeast, and fungal mycelia that produce mushrooms, can be grown in the dark directly at the outlet of the acetate-rich electrolyser, according to the researchers.
They said that growing algae using this technology is about four times more energy efficient than growing it conventionally using natural photosynthesis, and producing yeast is nearly 18 times more efficient than it is normally grown.
“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,” said Elizabeth Hann, co-author of the study.
“This technology is a more efficient method of turning solar energy into food, compared to food production that relies on biological photosynthesis,” Hann said.
The researchers said that a wide variety of cultures can take the acetate produced and turn it into the key molecular building blocks needed for organisms to grow and thrive.
Coupling this approach with existing systems for producing energy from sunlight “can increase the efficiency of converting solar energy into food by about four times” over natural photosynthesis, the scientists said, adding that the technology has enabled a ” reimagining how food can be produced in controlled environments”. environments”.
Scientists said releasing crops from dependence on the sun and instead producing them using artificial photosynthesis could open doors for food production in increasingly difficult conditions imposed by the man-made climate crisis and its security challenges. resulting food.
“Using 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, lessening the impact that agriculture has on the environment,” said Dr. Jinkerson.
“And for agriculture in non-traditional environments like outer space, increasing energy efficiency can help feed more crew with fewer inputs,” he added.