Food is the first priority for the people, and food security is a major issue related to the long-term stability of the country and the people's living and working in peace and contentment. Today, global food demand is growing, but the upper limit of food production is restricted by the energy conversion efficiency of photosynthesis (only 1% or less). Therefore, large areas of land are needed to grow crops to obtain the necessary solar energy to provide sufficient food.
In this regard, if we can create a new kind of "photosynthesis" that does not rely on solar energy, can we overcome the limitations of energy conversion efficiency, allowing us to produce more food using fewer resources?
On June 23, 2022, University of California, Riverside, Robert Jinkerson and University of Delaware Jiao Feng and others published in Nature sub-journal Nature Food entitled: A hybrid inorganic-biological artificial photosynthesis system for Research paper on energy-efficient food production.
This research has developed a method that does not require biological photosynthesis at all, and uses " artificial photosynthesis " to create food that does not rely on sunlight. The technology uses a two-step electrocatalytic process to convert carbon dioxide, electricity and water into acetate, allowing food-producing organisms to grow in a dark environment by consuming acetate. This organic-inorganic hybrid system can improve the efficiency of converting sunlight into food. The conversion efficiency of some foods is even 18 times that of biological photosynthesis.
Photosynthesis has evolved in plants for millions of years. Most crops can convert water, carbon dioxide and sunlight energy into sucrose, starch and other foods that humans can ingest. However, the energy conversion efficiency of photosynthesis is very low, and only about 1% or less of the solar energy is ultimately stored in food.
is subject to this limitation, and even though scientists have conducted extensive breeding and genetic engineering efforts to provide with improved photosynthetic efficiency , selective harvests have only been achieved in a limited number of food crops. Therefore, in this latest study, the research team tried to abandon the traditional photosynthesis pathway and find a method that does not require biological photosynthesis at all - to create food that does not rely on sunlight through " artificial photosynthesis ".
Artificial photosynthesis aims to overcome the limitations of biological photosynthesis, including low solar energy capture efficiency and poor carbon dioxide reduction, providing an alternative pathway for food production. Recent research has shown that through the electrolysis process, CO2 and H2O can be converted into reducing compounds such as carbon monoxide, formate, methanol and hydrogen, and then fermented by engineered bacteria to obtain fuels and chemicals.
Notably, acetate is a soluble two-carbon substrate that can be produced by electrochemical methods and is more readily metabolized by a variety of organisms. Based on this, the researchers designed a new experimental idea - using acetate produced by CO2 electrolysis to cultivate food-producing organisms, so that food production is independent of biological photosynthesis.
Schematic diagram of artificial photosynthesis
To integrate all the components of the system, the research team optimized the output of the electrolyzer to increase acetate production while also reducing the amount of salt used, resulting in the best results to date The highest level of acetate produced in the electrolyzer to support the growth of feeding organisms.
The co-corresponding author of the study and Professor Jiao Feng of the University of Delaware said that the most advanced two-step series CO2 electrolysis device developed in this study can achieve highly selective production of acetate. This is Unavailable via traditional CO2 electrolysis route.
Traditional two-step series CO2 electrolysis device (top) and optimized two-step series CO2 electrolysis device (bottom)
Further experiments showed that a variety of food-producing organisms, such as green algae , yeast and mushroom-producing fungi, which can grow and reproduce directly in a dark environment using acetate generated by electrolytic cells.What’s even more exciting is that the energy conversion efficiency of algae produced by through this technology is about four times that of photosynthesis! The energy conversion efficiency of yeast production is 18 times higher than that typically grown using sugar extracted from corn.
Green algae, yeast and mushroom-producing fungi can use acetate for heterotrophic growth
Not only that, the research team also investigated the potential of using this technology to grow crops, and the results showed that cowpeas, tomatoes, tobacco, rice, rapeseed A variety of conventional crops, such as green beans and green beans, can use acetate to grow in a dark environment.
Elizabeth Hann, the first author of the study, said this research shows that many crops can absorb the acetate we provide to grow and reproduce. Through some breeding and engineering research currently underway, it may be possible to use acetate as an additional energy source to grow crops to increase crop yields.
A variety of conventional crops can be grown using acetate in a dark environment.
The research significance of this technology is undoubtedly extraordinary. It can liberate agriculture from complete dependence on the sun and help in the era of climate change. The background offers countless possibilities for food growing. Imagine that if this technology could be popularized, humans would be able to grow crops anywhere, and the threats to global food security caused by natural disasters such as droughts and floods would be greatly reduced, and it would even provide food security for future space exploration.
It is worth mentioning that this technology participated in NASA Deep Space Food Challenge and became the winner of the first phase. The Deep Space Food Challenge is an international competition to create novel, game-changing food production technologies for long-duration space missions that require minimal input and maximize the output of safe, nutritious and delicious food.
Professor Robert Jinkerson, the co-corresponding author of the study, said that this research is a paradigm shift in human food production. Through this technology, food production efficiency is not only improved, but also land requirements and climate environmental impacts are reduced. For space exploration, improvements in energy conversion efficiency can help feed more astronauts with less investment.
Artificial photosynthesis is more energy-efficient than biological photosynthesis in plant- and algae-based food production
In conclusion, this study developed a new, sun-independent "artificial photosynthesis", Acetate is produced efficiently through a specially designed electrolyzer, and then a variety of food-producing organisms are cultivated, thus breaking through the upper limit of energy conversion efficiency of traditional photosynthesis, which can be up to 18 times.
Imagine that maybe one day in the future, huge containers based on this technology can "grow" a variety of crops in the dark, on the moon or Mars, and human interstellar immigration will step forward A big step.
paper link :
https://www.nature.com/articles/s43016-022-00530-x
