Advances in Bioproduction of Feed Amino Acids in China.

Proteins are one of the essential macromolecules that constitute the foundation of life. Amino acids are the building blocks of proteins. Since the early production of monosodium glutamate (MSG), many amino acids have been widely produced for applications in pharmaceuticals, feed additives, and animal nutrition. In livestock and poultry industries, feed amino acids help reduce crude protein content and balance animal nutrition. Amid global food security concerns, demand is growing for amino acids to lessen the reliance on soybean meal in feed. Thanks to their higher quality and lower cost relative to chemical methods, most amino acids are now produced via microbial fermentation. Among these, L-lysine, L-methionine, and L-threonine account for the majority of global consumption, representing approximately 80-90% of the total feed amino acid market. Other amino acids such as L-tryptophan, L-isoleucine, L-valine, L-histidine, and L-arginine command a small market share due to their limited production capacity. Therefore, improving the efficiency of producing amino acids for animal feed is crucial. This is not only about securing better feed supply chains but also a major step toward building a more sustainable livestock industry. Synthetic biology uses renewable resources or CO2 as raw materials, replacing traditional chemical synthesis. Synthetic biology has been continuously improving in areas such as gene editing, metabolic pathway regulation, and AI-assisted design, leading to a continued decline in the production costs of minor amino acids such as valine, tryptophan, isoleucine, arginine, and histidine. This technological advance is expected to drive further expansion in demand for these minor amino acids, thereby pushing the whole feed amino acid market growth even higher.In this chapter, we review the technologies and strategies employed in developing high-yield strains for the five feed minor amino acids (L-tryptophan, L-isoleucine, L-valine, L-histidine, and L-arginine). This section reviews the development of China's feed amino acid industry, covering production strategies, key manufacturers, the country's share of global capacity, and future growth prospects.