For millions of years, photosynthesis has developed within plants to
convert water, carbon dioxide, and solar energy into plant biomass and the
meals humans consume. However, this mechanism is incredibly inefficient, as
just 1% of the energy from sunlight actually reaches the plant. By adopting
artificial photosynthesis, researchers from the Universities of Delaware and
Riverside have discovered a means to produce food without of the requirement
for biological photosynthesis.
The study, which was published in the journal
Nature Food, used a two-step electrocatalytic process to transform carbon dioxide,
energy, and water into acetate, which is the chemical form of vinegar's
primary ingredient. Then, in the dark, organisms that produce food use
acetate. This hybrid organic-inorganic system might boost the conversion
efficiency of sunlight into food, up to 18 times more efficient for some
crops, when combined with solar panels to create the electricity to fuel the
electrocatalysis.
According to corresponding author
Robert Jinkerson, an assistant professor of chemical and environmental engineering at UC
Riverside, "with our approach we sought to identify a new way of producing
food that could break through the limits imposed by biological
photosynthesis."
The output of the electrolyzer was tuned to assist the growth of
food-producing organisms in order to unite all the parts of the system.
Electrolyzers are machines that utilize electricity to transform unusable
chemicals and products, such carbon dioxide, into basic resources. The
greatest amounts of acetate ever generated in an electrolyzer to date were
achieved by increasing the amount of acetate produced while lowering the
amount of salt utilized.
"Using a state-of-the-art two-step tandem CO2 electrolysis setup developed
in our laboratory, we were able to achieve a high selectivity towards
acetate that cannot be accessed through conventional CO2 electrolysis
routes," stated corresponding author Feng Jiao of the University of
Delaware.
Experiments revealed that a variety of food-producing species, including
green algae, yeast, and fungal mycelium that produces mushrooms, can be
grown in the dark directly on the acetate-rich electrolyzer output. With
this method, producing algae is about four times more energy-efficient than
growing it photosynthesis. Production of yeast uses roughly 18 times less
energy than conventional methods, which commonly use sugar from corn.
"We were able to cultivate creatures that could produce food without the
assistance of biological photosynthesis. These creatures are often grown on
plant-based sugars or petroleum-based inputs, which are byproducts of
biological photosynthesis that occurred millions of years ago. Compared to
food production that depends on biological photosynthesis, this technique is
a more effective way to convert solar energy into food, according to
Elizabeth Hann, a PhD candidate at the Jinkerson Lab and co-lead author of
the paper.
It was also looked at if this technique might be used to raise crops. When
grown in the dark, cowpea, tomato, tobacco, rice, canola, and green pea were
all able to use carbon from acetate.
We discovered that a variety of plants could use the acetate we gave to
create the essential molecules a creature needs to develop and flourish. "We
may be able to grow crops with acetate as an additional energy source to
boost crop yields with some breeding and engineering that we are currently
working on," said Marcus Harland-Dunaway, a PhD candidate at the Jinkerson
Lab and co-lead author of the study.
Artificial photosynthesis opens the door to endless options for growing
food under the increasingly challenging conditions imposed by anthropogenic
climate change by releasing agriculture from total dependency on the light.
If crops for people and animals grew in less resource-intensive, regulated
conditions, drought, floods, and decreased land availability would be less
of a danger to global food security. Additionally, crops might be cultivated
in urban areas and other regions that are now unsuited for agriculture, even
providing nourishment for future space travelers.
It may be possible to change the way humans are fed by using artificial
photosynthesis techniques. As food production becomes more efficient, less
land is required, reducing the environmental effect of agriculture.
Additionally, the improved energy efficiency might help feed more crew
members while using less inputs for agriculture in non-traditional areas,
like as space, according to Jinkerson.
This method of food production was entered into the NASA Deep Space Food
Challenge and won Phase I. The Deep Space Food Challenge is an international
competition where teams compete for cash awards to develop unique and
game-changing food technologies that use few inputs and provide the most
safe, nourishing, and appetizing meals possible for extended space
journeys.
How much simpler would it be for future Martians if enormous boats could
produce tomato plants in the dark on Mars in the future? stated co-author
and head of the UC Riverside Plant Transformation Research Center
Martha Orozco-Cárdenas.
The study also included contributions from Sean Overa, Dang Le, and Andres
Narvaez. You can see the open-access article, "A hybrid inorganic-biological
artificial photosynthesis system for energy-efficient food production,"
here.
The Foundation for Food and Agriculture Research (FFAR), the Link
Foundation, the National Science Foundation of the United States, the U.S.
Department of Energy, and the Translational Research Institute for Space
Health (TRISH) under NASA (NNX16AO69A) all provided funding for the study.
The writers alone are responsible for the publication's content, which does
not necessarily reflect the Foundation for Food and Agriculture Research's
official positions.
