Artificial photosynthesis can produce food without sun

The plants are growing in complete darkness on an acetate medium that replaces biological photosynthesis. Credit: Marcus Harland-Dunaway/UCR

Photosynthesis has evolved in plants over millions of years to turn water, carbon dioxide and the energy of sunlight into plant biomass and the food we eat. This process, however, is very inefficient, with only about 1% of the energy found in sunlight ending up in the plant. Scientists at UC Riverside and the University of Delaware have discovered a way to completely bypass the need for biological photosynthesis and create sunlight-independent food using artificial photosynthesis.

The research, published in Natural food, uses a two-step electrocatalytic process to convert carbon dioxide, electricity and water into acetate, the form of vinegar’s main component. Food-producing organisms consume acetate in the dark to grow. Combined with solar panels to generate electricity to power electrocatalysis, this organic-inorganic hybrid system could increase the efficiency of converting sunlight into food, up to 18 times more efficient for some foods.

“With our approach, we sought to identify a new way of producing food that could break the limits normally imposed by biological photosynthesis,” said corresponding author Robert Jinkerson, assistant professor of chemical and environmental engineering at UC Riverside.

In order to integrate all system components together, the electrolyser output has been optimized to support the growth of food-producing organisms. Electrolyzers are devices that use electricity to convert raw materials like carbon dioxide into useful molecules and products. The amount of acetate produced was increased while the amount of salt used was decreased, resulting in the highest levels of acetate ever produced in an electrolyzer to date.

“Using a state-of-the-art two-stage tandem COtwo electrolysis configuration developed in our laboratory, we were able to obtain a high selectivity towards acetate that cannot be accessed by conventional COtwo electrolysis pathways,” said corresponding author Feng Jiao of the University of Delaware.

Experiments have shown that a wide range of food-producing organisms can be grown in the dark directly at the output of the acetate-rich electrolyser, including green algae, yeast and fungal mycelium that produce mushrooms. Producing algae with this technology is approximately four times more energy efficient than growing them photosynthetically. Yeast production is about 18 times more energy efficient than is typically grown with sugar extracted from corn.

A fotossíntese artificial pode produzir alimentos sem soltwo. Thethe electrolysis of COtwo uses electricity (generated by photovoltaics) to convert COtwo and HtwoO in O two and acetate. This process has been optimized to produce an ideal effluent outlet to support the growth of food producing organisms. B, chlamydomonas, Saccharomycesmushroom-producing fungi and a variety of vascular plants were cultivated using the effluent produced by the electrolyser. ç, Organisms grown using the effluent produced by the electrolyser serve as food or food products. This system is able to make food independent of photosynthesis, using COtwoHtwoThe and solar energy. Credit: Nature Food (2022). DOI: 10.1038/s43016-022-00530-x”/>

A combined electrochemical-biological system for food production from COtwo. oneCOtwo electrolysis uses electricity (generated by photovoltaics) to convert COtwo and HtwoO in Otwo and acetate. This process has been optimized to produce an ideal effluent outlet to support the growth of food producing organisms. B, chlamydomonas, SaccharomycesMushroom-producing fungi and a variety of vascular plants were cultivated using the effluent produced by the electrolyser. ç, Organisms grown using the effluent produced by the electrolyser serve as food or food products. This system is able to make food independent of photosynthesis, using COtwoHtwoThe and solar energy. Credit: Natural food (2022). DOI: 10.1038/s43016-022-00530-x

“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. The technology is a more efficient method of turning solar energy into food, compared to food production that relies on biological photosynthesis,” said Elizabeth Hann, a PhD student at the Jinkerson Laboratory and co-lead author of the study.

The potential of employing this technology to grow plants was also investigated. Cowpea beans, tomatoes, tobacco, rice, canola and green peas were all able to utilize carbon from acetate when grown in the dark.

“We found that a wide range of cultures could take the acetate we provide and turn it into the key molecular building blocks that an organism needs to grow and thrive. With some breeding and engineering that we’re currently working on, we might be able to grow cultures with acetate as an extra energy source to increase crop yields,” said Marcus Harland-Dunaway, a doctoral candidate at the Jinkerson Laboratory and co-lead author of the study.

By freeing agriculture from total dependence on the sun, artificial photosynthesis opens the door to countless possibilities for growing food in the increasingly difficult conditions imposed by anthropogenic climate change. Droughts, floods and reduced land availability would be less of a threat to global food security if crops for humans and animals were grown in controlled environments and with fewer resources. Crops can also be grown in cities and other areas currently unsuitable for agriculture and even provide food for future space explorers.

“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. And for agriculture in non-traditional environments such as outer space, increased energy efficiency can help feed more crew with fewer inputs,” said Jinkerson.

This approach to food production was submitted to NASA’s Deep Space Food Challenge, where it was the winner of Phase I. The Deep Space Food Challenge is an international competition where prizes are awarded to teams for creating innovative and revolutionary food technologies that require inputs. minimum and maximize the production of safe, nutritious and palatable food for long-duration space missions.

“Imagine one day giant ships growing tomato plants in the dark and on Mars – would that be much easier for future Martians?” said co-author Martha Orozco-Cárdenas, director of the UC Riverside Plant Transformation Research Center.


The future of biofuels in the dark


More information:
Elizabeth C. Hann et al, An inorganic-biological hybrid artificial photosynthesis system for energy efficient food production, Natural food (2022). DOI: 10.1038/s43016-022-00530-x

Provided by the University of California – Riverside

Quote: Artificial Photosynthesis Can Produce Sunless Food (2022, June 23) retrieved June 24, 2022 from https://phys.org/news/2022-06-artificial-photosynthesis-food-sunshine.html

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