Artificial photosynthesis for environmentally friendly food production
Ensuring the supply of food to the constantly growing world population and protecting the environment at the same time are often conflicting objectives. Now researchers at the Technical University of Munich (TUM) in Germany have successfully developed a method for the synthetic manufacture of nutritional protein involving a type of artificial photosynthesis.
The animal feed industry is the primary driver of high demand for large volumes of nutritional protein, which is also suitable for use in meat substitute products.
A group of scientists headed by Professor Volker Sieber of the TUM Professorship for Chemistry of Biogenic Resources at the Campus Straubing for Biotechnology and Sustainability (TUMCS) have succeeded in producing the amino acid L-alanine, an essential building block in proteins, from the environmentally harmful gas CO2. Their indirect biotechnological process involves methanol as an intermediate.
Until now, protein for animal feed has been typically produced in the southern hemisphere with large-scale agricultural space requirements and negative consequences for biodiversity.
The CO2, which is removed from the atmosphere, is first turned into methanol using green electricity and hydrogen. The new method converts this intermediate into L-alanine in a multi-stage process using synthetic enzymes. It is extremely effective and generates very high yields. L-alanine is one of the most important components of protein, which is essential to the nutrition of both humans and animals.
"Compared to growing plants, this method requires far less space to create the same amount of L-alanine, when the energy used comes from solar or wind power sources,” Sieber explains. “The more efficient use of space means that a kind of artificial photosynthesis can be used to produce the same amount of foodstuffs on significantly fewer acres. This paves the way for a smaller ecological footprint in agriculture."
Bioeconomy and hydrogen economy in combination
The manufacture of L-alanine is only the first step for the scientists. "We also want to produce other amino acids from CO2 using renewable energy and to further increase efficiency in the realisation process," says co-author Vivian Willers, who developed the process as a doctoral candidate at the TUM Campus Straubing.
The researchers add that the project is a good example of how bioeconomy and hydrogen economy in combination can enable the achievement of more sustainability.