For millions of years, plants have developed photosynthesis to convert
carbon dioxide, water, and solar energy into plant biomass and food for
humans to consume. Only around 1% of the energy in sunlight is actually used
by the plant due to this extremely inefficient mechanism. By employing
artificial photosynthesis, researchers at UC Riverside and the University of
Delaware have discovered a technique to produce food without the need for
biological photosynthesis at all.
The study, which was published in
Nature Food, used a two-step electrocatalytic process to change carbon dioxide, water,
and energy into acetate, which is vinegar's primary ingredient. Then, in the
dark, food-producing organisms develop by consuming acetate. When coupled
with photovoltaic cells to supply the energy for the electrocatalysis, this
hybrid organic-inorganic system has the potential to enhance
sunlight-to-food conversion efficiency by up to eighteen times for certain
food types.
"We aimed to discover a novel method of food production that could surpass
the constraints typically imposed by biological photosynthesis," stated
corresponding author
Robert Jinkerson, an assistant professor of chemical and environmental engineering at UC
Riverside.
The electrolyzer's output was tuned to promote the development of organisms
that produce food in order to integrate all the system's components.
Electrolyzers are machines that use electricity to create usable chemicals
and products from raw materials like carbon dioxide. The greatest amounts of
acetate ever generated in an electrolyzer were achieved by increasing the
amount of acetate produced while decreasing the amount of salt needed.
According to corresponding author Feng Jiao of the University of Delaware,
"we were able to achieve a high selectivity towards acetate that cannot be
accessed through conventional CO2 electrolysis routes using a
state-of-the-art two-step tandem CO2 electrolysis setup developed in our
laboratory."
Experiments revealed that a variety of food-producing organisms, such as
green algae, yeast, and fungal mycelium that produces mushrooms, may be
grown in the dark directly on the acetate-rich electrolyzer output. Using
this approach, algae may be produced at an energy efficiency around four
times higher than when grown photosynthetically. Compared to traditional
methods of cultivation that use maize sugar, yeast culture is approximately
eighteen times more energy-efficient.
Food-producing creatures might be grown by us without the aid of biological
photosynthesis. These creatures are usually grown on plant-derived sugars or
petroleum-derived 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 doctorate
candidate at the Jinkerson Lab and co-lead author of the paper.
It was also looked at if this technique might be used to produce
agricultural plants. When grown in the dark, cowpea, tomato, tobacco, rice,
canola, and green pea might all use the carbon from acetate.
We discovered that a variety of crops could use the acetate we supplied to
create the essential molecular building blocks required by living things in
order to develop and flourish. Co-lead author of the study and doctorate
candidate at the Jinkerson Lab Marcus Harland-Dunaway stated, "We might be
able to grow crops with acetate as an extra energy source to boost crop
yields with some breeding and engineering that we are currently working
on."
Artificial photosynthesis frees agriculture from total solar dependency,
creating a plethora of opportunities for food production in the face of
increasingly challenging environmental conditions brought on by human-caused
climate change. Global food security would be less threatened by droughts,
floods, and a shortage of land if crops for people and animals were grown in
regulated, less resource-intensive habitats. Not only might crops be
produced in places that aren't now appropriate for agriculture, such cities,
but they could also be cultivated to feed space travelers in the
future.
The production of food by artificial photosynthesis has the potential to
revolutionize the way humans eat. Agriculture's environmental effect is
reduced when more land is needed for food production, which increases
efficiency. Jinkerson said, "And the increased energy efficiency could help
feed more crew members with less inputs for agriculture in non-traditional
environments, like space."
This food production method was entered into NASA's Deep Space Food
Challenge and was selected as a Phase I winner. Teams who develop innovative
and revolutionary food technologies that optimize safe, nutrient-dense, and
tasty food outputs for extended space missions while requiring the least
amount of inputs are eligible to win awards in the Deep Space Food
Challenge, an international competition.
Imagine massive spacecraft cultivating tomatoes in the dark on Mars at some
point. Can you imagine how much simpler it would be for future Martians?
stated
Martha Orozco-Cárdenas, a co-author and the director of the Plant Transformation Research Center
at UC Riverside.
Sean Overa, Dang Le, and Andres Narvaez also made contributions to the
study. A hybrid inorganic–biological artificial photosynthesis system for
energy-efficient food production is described in this
open-access publication.
The study was funded by the U.S. Department of Energy, the Foundation for
Food and Agricultural Research (FFAR), the Link Foundation, the U.S.
National Science Foundation, the U.S. National Science Foundation, and the
Translational Research Institute for Space Health (TRISH) through NASA
(NNX16AO69A). The Foundation for Food and Agriculture Research does not
necessarily endorse the opinions expressed in this publication; the writers
alone are responsible for its content.
