The combination of solar energy and microbes could produce 10 times more protein than crops such as soybeans, according to a new study.
The system would also have very little impact on the environment, the researchers said, unlike animal husbandry which results in huge amounts of greenhouse gases as well as water pollution.
The concept uses electricity from solar panels and carbon dioxide from the air to create fuel for microbes, which are grown in bioreactor tanks and then made into dry protein powders. The process uses land, water and fertilizers very efficiently and could be deployed anywhere, not just in countries with strong sunshine or fertile soils, the scientists said.
Food security is a “critical issue” for humanity in the decades to come, they said, with growing world population, biofuels competing for land with crops and an estimated 800 million people already under. -powered today. In addition, tackling the climate crisis will be nearly impossible without reducing emissions from the production of animal and dairy foods.
Microbes are already used to make many common foods, such as bread, yogurt, beer, and Quorn. But other researchers have said that converting consumers to consuming microbial protein may be difficult, and these foods may not be nutritionally complete.
Dorian Leger, from the Max Planck Institute for Molecular Plant Physiology in Potsdam, Germany, who led the new analysis, said: “We believe that microbial foods hold great promise and will be one of the major contributors to the resolution of the potential food crisis.
“It could accelerate quite quickly on the consumer side, but it’s hard to say. “But I exercise, and if I was offered a bacterial protein shake now, I would have it.”
The team focused on soybeans, as they are linked to the destruction of forests and are primarily fed to animals, but other bacteria produce the main building blocks of palm oil. “Bacteria are very flexible, so they could potentially be adapted to different products,” Leger said.
At least a dozen companies are already producing animal feed from microbes but bacteria are usually fed either on sugars from other crops or on methane or methanol from fossil fuels. Solar food, based in Finland, uses electricity to create food for humans.
The new assessment, published in the journal Proceedings of the National Academy of Sciences of the United States of America, is the first quantitative comparison of land use and energy efficiency between traditional agriculture and solar-powered microbial production systems.
The researchers used data from today’s technologies to calculate the efficiency of each step of the process, including CO capture.2 from the air and turn germs into food for people to eat. They found that the microbial system only uses 1% of the water needed for crops and a small fraction of the fertilizer, most of which is wasted when used in the fields.
The analysis estimated that the solar-microbial process could produce 15 tonnes of protein from each hectare (or per 2.5 acres) per year, enough to feed 520 people, which scientists said was a conservative estimate. . In comparison, one hectare of soybeans could produce 1.1 tonnes of protein and feed 40 people. Even in countries with relatively low levels of sunshine as in the UK, microbial protein production was at least five times higher per hectare than that of plants.
The microbial protein would cost roughly the same as current proteins consumed by humans, such as whey or peas, the researchers suggested. But it was several times more expensive than current feed, although future technological improvements are expected to reduce costs.
Leger said that plants’ ability to photosynthesize is remarkable, but in terms of energy efficiency, staple crops only convert about 1% of solar energy into edible biomass. Indeed, plants have evolved to compete and reproduce as well as to grow and use less of the spectrum of sunlight than photovoltaic panels.
All of the system components exist, but Leger said they now need to be tested together and on a large scale, especially CO capture.2 air and ensuring that used solar panels can be recycled. “For human food there are also a lot of regulations that need to be overcome,” he said.
Pete Iannetta, from the James Hutton Institute in Scotland, said: “It’s a really interesting concept – you separate food production from land use, which would mean you could have all of that land available for rewilding. “
But he said that food is not only made up of the main nutrients, like protein and carbohydrates: “There are a lot of secondary compounds that are important for your well-being.” Iannetta also wondered if microbial foods would become mainstream: “For example, we’ve been using algae for a long time as a potential food resource, but it’s still not widely accepted. “
Dr Toby Mottram, an agricultural technology consultant, said: “Until the model is tested and costed with a pilot plant, including a life cycle assessment of [solar panel] production, it is difficult to say if it is improving [farming] systems that have been maintained for thousands of years, albeit for a smaller population than we plan to feed.