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Tübingen Biotechnology Team Converts Simple Ingredients into Folic Acid Using Microbes

By iednewsdesk On Oct 10, 2024

Take carbon dioxide, hydrogen and oxygen as well as electricity from renewable sources – that’s all a bacterium and baker’s yeast need to produce proteins for human nutrition and the vital vitamin B9 in a sophisticated bioreactor system in the laboratory. This result was achieved by a research team led by Professor Lars Angenent from the environmental biotechnology department at the University of Tübingen during the further development of its power-to-protein system. The new protein product with vitamin B9, folic acid, can serve as a vegan basis for meat substitutes, which could be used to feed a growing world population in a climate-friendly way in the long term. The study was published in the journal Trends in Biotechnology.

Although many microbes make a rather unspectacular visual impression, they can produce a huge variety of substances, which humans take advantage of in the production of beer, wine and cheese, for example. “We had previously developed a power-to-protein technology: This involves using two different microbes one after the other: a Clostridium bacterium reduced carbon dioxide with hydrogen in the absence of air to form acetate, which the baker’s yeast, a fungus, then converted into proteins in the presence of air,” explains Angenent. This first system only worked, however, if the microbes were provided with certain vitamins such as B9. “Humans cannot survive on protein alone,” says Angenent. “That’s why we wanted to produce vitamin B9.” The aim is not to feed more vitamins into the process than can be obtained.

More frugal bacteria

Together with his team, Angenent replaced the Clostridium bacterium in the first stage with the bacterium Thermoanaerobacter kivui, which is more frugal and can produce the folic acid needed to produce acetate itself. In the second step, the baker’s yeast produced such large amounts of folic acid that it can be used. It was known that baker’s yeast can produce folic acid from sugar. “So it does this with about the same amount of acetate as a starting material, as our experiments show. Since we no longer add vitamin B9, we are sure that it is produced in the process,” says the researcher. About six grams of the yeast produced and dried would be enough for a person as a daily dose of vitamin B9. The vitamin measurements in the experiments were carried out by a team led by Professor Michael Rychlik from the Technical University of Munich, one of the co-authors of the study.

“Our product is not yet a finished food, but the food industry can develop it into one,” says Angenent. First, substances that can cause gout must be removed from the yeast before consumption. In addition, the small bioreactor system must be transferred from the laboratory to a much larger-scale facility, which can raise new problems. Food safety studies must follow, as well as technical and economic analyses of the sales market for such products.

Thinking in Cycles

But how far does Angenent want to go with his vision of food replacement? Should we live on synthetic pills and pastes in the long term? “My main concern is reducing meat consumption,” says the researcher. “I believe that consumers will get used to new products. This can also be achieved through price.” In this way, the cultivation of animal feed can be greatly reduced, as can the climate-damaging emissions from livestock farming. Overall, however, more agriculture is needed than before, and plant cultivation that conserves resources as much as possible must be expanded. In addition, farmers should also be financially rewarded in the future for a new responsibility: protecting the soil and nature.

Angenent thinks in cycles and in larger contexts: “The growing world population is threatened by malnutrition, especially in countries that suffer from droughts and whose soils contain too few nutrients. Substitute products such as those we produce could improve the nutritional situation,” he says. “The fact that we can simultaneously produce proteins and vitamins for sustainable vegetarian and vegan products at a high rate in our bioreactor system without using any significant amount of land is a great success on this path.”

University of Tübingen