Flow Reactor Created that Will Be Able to Mass Produce Amino Acids

Researchers at Kyushu University have developed highly efficient amino acid synthesis from biomass-derivable acids and water using electric energy.

Amino acids are the basic building blocks of proteins and are also involved in various functional materials such as feed additives, flavor enhancers, and pharmaceuticals.

Above – A demonstration flow reactor constructed by researchers at Kyushu University continuously converts source materials into amino acids through a reaction driven by electricity. By choosing the right combination of electrocatalyst and source materials, the researchers achieved highly efficient synthesis of amino acids. This method for producing amino acids is less resource intensive than current methods, and similar methods may one day be used for providing people living in space with some of the essential nutrients they need to survive. CREDIT Szabolcs Arany, Kyushu University

They built a flow reactor that can electrochemically synthesize the amino acids continuously and it can be scaled up production in the future.

Current methods for artificially producing amino acids are based on fermentation using microbes, a process that is time and resource-intensive. It is not practical to produce these vital nutrients in space-limited and resource-restricted conditions.

Researchers succeeded in efficiently synthesizing several types of amino acids using abundant materials. The overall reaction is simple, but needed the right combination of starting materials and catalyst to get it to actually work without relying on rare materials.

The researchers settled on a combination of titanium dioxide as the electrocatalyst and an organic acid called alpha-keto acid as the key source material. Titanium dioxide is abundantly available on Earth, and alpha-keto acid can be easily extracted from woody biomass.

Placing the alpha-keto acid and a source of nitrogen, such as ammonia or hydroxylamine, in a water-based solution and running electricity through it using two electrodes, one of which was titanium dioxide, led to synthesis of seven amino acids–alanine, glycine, aspartic acid, glutamic acid, leucine, phenylalanine, and tyrosine–with high efficiency and high selectivity even under mild conditions.

Hydrogen, which is also needed as part of the reaction, was generated during the process as a natural result of running electricity between electrodes in water.