Food crops can they thrive in the dark? Researchers are figuring it out.

 Food crops can they thrive in the dark? Researchers are figuring it out. A technology that could one day help feed astronauts and a crowded planet is the possibility of sustaining plants without photosynthesis, according to experiments.

Food crops can they thrive in the dark? Researchers are figuring it out.

Science fiction tales have depicted people from the future residing in free-floating space stations, asteroids with hollowed out interiors, and underground cities on Mars. However, if humans are ever to survive in any of those hostile and foreign environments, they will need to find ways to grow food while making the most of scarce resources; photosynthesis, the wildly successful but energy-inefficient process by which plants convert sunlight into sugar, may not be sufficient.

Some scientists are now considering whether growing plants in the dark instead of photosynthesis would allow for more effective food production.

The concept is as far-fetched as cities on Mars. With a study that was released in Nature Food in June, a team of researchers has, nevertheless, made a first step toward realising it. According to the research, it is possible to grow algae, edible yeast, and fungus that produce mushrooms in the dark by providing them with acetate, a carbon-based chemical that is not derived from plants but rather is produced using solar energy. The researchers are optimistic that this technique, which is a form of artificial photosynthesis, could open up new opportunities for food production that require less physical area and energy than conventional agriculture—possibly even crops that can grow in the dark.

Other experts are excited by the technology the researchers have developed and the team's novel idea for increasing the efficiency of food production, but they are sceptical that it would ever be able to so fundamentally restructure plant biology.

According to research co-author Feng Jiao, a professor of chemical and biomolecular engineering at the University of Delaware, we need to find ways to grow plants more effectively. Which is the best [solution]? The beauty of science, in my opinion, is that we investigate every possibility.

Higher productivity than nature

All life on Earth is powered by the sun, with the exception of a few extreme situations like deep-sea hot springs, which are sustained by the chemical energy of hydrogen sulphide erupting out of cracks in the seafloor. Even apex predators like tigers and sharks are a part of intricate food webs that can be traced back to plants and, in the case of the oceans, microscopic green algae. These so-called primary producers have a biological superpower that allows them to convert carbon dioxide into organic carbon through a biochemical process called photosynthesis, which is fueled by sunlight.

However, even though photosynthesis is necessary for life as we know it, it is not very effective; only a small portion of the sunlight that hits plants is actually collected and converted into organic carbon. If humanity are ever to create a self-sustaining presence in space, it will be difficult to generate food using as few resources as possible due to this inefficiency.

As the human population increases and farmers are under pressure to produce more food from the same amount of land, it is an issue on Earth as well.

Some experts think that genetically modifying crops to photosynthesize more effectively will provide a solution. The authors of the current study suggest replacing biological photosynthesis with a partially artificial method of converting sunlight into food, which is more novel. They use a technique known as artificial photosynthesis, which has been around for a while and refers to a variety of methods for transforming light, water, and CO2 into liquid fuels and compounds like formate, methanol, and hydrogen. The authors of the new study claim that this is the first time an artificial photosynthesis system has been used in conjunction with an effort to cultivate widespread food-producing plants.

Their method is based on electrolysis, which is the process of utilising an electrolyzer to use an electrical current to drive chemical processes. In their most recent research, the scientists developed a two-step electrolyzer system that uses solar energy to transform carbon dioxide and water into oxygen and acetate, a straightforward carbon-based molecule.

The authors then fed the photosynthetic green alga Chlamydomonas reinhardtii this acetate. Additionally, they supplied acetate to fungi that produce mushrooms and nutritional yeast. These organisms don't photosynthesize on their own and often need the organic carbon produced by plants in order to flourish.

All of these organisms were able to absorb the acetate and develop in the absence of light or carbon produced by photosynthetic processes.

The procedure proved remarkably effective when compared to photosynthesis. Green algae might produce biomass with artificial photosynthesis about four times more effectively than crops can using biological photosynthesis. This method produced yeast that was nearly 18 times more energy-efficient than crops.

This is one of the main benefits of adopting manufactured channels as opposed to natural ones, according to Jiao.

Cultivating plants in the dark?

The fact that the mixotrophic alga C. reinhardtii may alternate between producing its own food through photosynthetic processes and consuming organic carbon from other plants was already known to scientists. But this is the first time C. reinhardtii has been grown on acetate that wasn't made from either current photosynthesis or petroleum products, which are the fossil products of old photosynthesis, said senior study author Robert Jinkerson of the University of California, Riverside. That matters a lot.

According to Jinkerson, this is the first instance in which a photosynthetic organism, such as an algae or a plant, has developed without relying on photosynthesis. It has been totally detached.

After successfully growing algae devoid of photosynthesis, the researchers moved on to a trickier inquiry: Could they also cultivate crop plants?

Their preliminary findings were promising. To demonstrate that lettuce tissue can take up and digest an externally provided carbon source, the researchers in the dark cultivated lettuce tissue in a liquid mixture containing acetate.

And they discovered that the plants integrated acetate into their tissue when they cultivated complete lettuce plants in the light (as well as rice, canola, tomato, and numerous other crop species), but fed them additional acetate. Acetate containing the carbon-13 heavy isotope could be found in both amino acids and carbohydrates, indicating that plants may employ it to promote several metabolic activities.

In fact, the researchers' studies with lettuce suggested that using too much acetate actually slows plant growth. Despite this, the study did not demonstrate that full plants could be grown exclusively on acetate without access to sunlight. According to Jinkerson, his lab is presently engaged in breeding and genetic engineering plant species to increase their tolerance to acetate. That will be required for the team's artificial photosynthesis technique to significantly enhance plant growth and food production.

The discoveries of the authors, according to Emma Kovak, a food and agriculture specialist at the Breakthrough Institute, are a first step toward maybe employing acetate to assist feed plants for indoor production. If it enables producers to lower the indoor light levels, that might reduce the energy required to operate indoor farms. However, Kovak notes that in order to allow plants to grow robustly using acetate even in low-light situations, huge improvement would be essential.

Evan Groover, a University of California, Berkeley PhD candidate in synthetic biology whose work focuses on genetically modifying plants to enhance photosynthesis, concurs. According to Groover, the study demonstrates that plants can ingest acetate, but it is not evidence that they can genuinely flourish on that or significantly manufacture food, fuel, or medication. According to him, achieving the latter would necessitate totally rewiring plants.

Groover claims that he considered the authors' paper to be exhilarating at the same time.

According to him, this research shows us methods in which we could be able to capture light and carbon in odd, extraterrestrial habitats, or conditions where you can't perform typical farming.

A deep space diet

The technology developed by the researchers might be used for the first time in an extraterrestrial setting. The researchers participated in NASA's Deep Space Food Challenge, which offers prizes and recognition to teams with creative concepts for feeding astronauts on extended space missions, and entered their concept of artificial photosynthesis. The team's idea was chosen as one of the 18 U.S.-based Phase 1 winners last fall. These teams must construct a prototype that really produces food in Phase 2. Winners will be revealed the next year.

A revolutionary food production technique may not be used on a future space mission even if it wins the competition. According to Lynn Rothschild, a senior research scientist at NASA's Ames Research Center who wasn't involved with the new study, many technical elements would need to be sorted out first. Weight is an important factor since artificial photosynthesis will probably necessitate sending new equipment into space, such as extra solar panels and electrolyzers.

But according to Rothschild, it's important to keep an open mind regarding the potential applications of any efforts to rebuild a fundamental biological process like photosynthesis, whether in space or on Earth: The reward could be something we haven't yet thought of.