Solar-powered process turns CO₂ into protein-building amino acids

Researchers at the Technical University of Munich (TUM) have developed a solar-powered process that converts carbon dioxide, hydrogen, and renewable energy into essential amino acids, potentially offering a sustainable solution to rising global food demands. According to United Nations projections, food demand could rise by approximately 60% by 2050, yet only about 2% more agricultural land is expected to be available. To address this challenge, scientists at the TUM Campus Straubing explored innovative methods to produce protein-building blocks more efficiently. The breakthrough involves a novel enzymatic system capable of transforming carbon dioxide into a variety of amino acids. The process begins with solar energy being captured and converted into electricity through photovoltaic systems. This electricity powers electrolysis to produce hydrogen, which, when combined with carbon dioxide, generates methanol, a versatile chemical intermediate. Specialized enzymes then catalyze the conversion of methanol into different amino acids, depending on the type of enzyme employed. Viktoria Lehmann, a doctoral researcher at the TUM Chair of Chemistry of Biogenic Resources, highlighted the significance of this method. She explained that livestock often requires supplementary protein beyond what grass provides, and traditional feed additives rely heavily on resources that strain environmental limits. By creating a more efficient method to produce these critical nutrients, the team aims to reduce the ecological footprint of protein supply chains. The study, published in Nature Communications, outlines how plants use sunlight to create biomass, though this process is inherently inefficient. The TUM team’s approach instead uses renewable energy to generate chemical energy carriers, which are then transformed into valuable protein components. Professor Volker Sieber, who leads the research, emphasized that this strategy could allow for better utilization of existing land and promote sustainability in amino acid production. Building upon earlier successes, the researchers expanded their capabilities. In 2023, they successfully produced the amino acid L-alanine from green methanol. Now, they have extended their methodology to synthesize six additional amino acids, glycine, serine, L-aspartic acid, L-valine, L-glutamic acid, and L-proline. Dr. Vivian Willers, whose doctoral research underpinned the study, described the system as a “plug-and-play” platform, akin to a construction set. This modular design enables flexibility in producing different amino acids tailored to specific applications. The implications extend beyond traditional farming. These amino acids are integral to nutrient media used in cultivated meat production, suggesting broader applications in alternative protein industries. The researchers envision a future where reliance on unsustainable feed ingredients, such as soy, is diminished. Despite these advancements, the current production levels remain insufficient for commercial deployment. The team is actively refining the efficiency of the enzymes involved to enhance scalability. Sieber noted that the project serves as a demonstration of technical viability rather than immediate industrial implementation. They have proven that a wide array of biologically relevant amino acids can be synthesized from CO₂-derived methanol, opening new avenues for sustainable protein production. This innovation marks a pivotal step toward addressing global food security challenges through advanced biochemical processes powered by renewable energy.