Amino acid biosynthesis pathway not only plays a key role in life activities, but also promotes the development of efficient and environmentally friendly amino acid production and synthetic biology in industrial fermentation. Proteins are the foundation of life, and they play a variety of roles in cells, from structural support to catalyzing chemical reactions. All proteins are made up of 20 different amino acids that are produced inside cells through complex biosynthesis processes. The discovery of 20 amino acids spanned nearly a century, beginning with the first isolation of glycine by the French chemist H. Braconnot in 1820, and ending with the discovery of threonine by W. Rose in 1935. The discovery of these amino acids involved many scientists whose work not only revealed the structure and properties of amino acids, It also laid the foundation for later biochemistry and molecular biology research. The biosynthesis of amino acids is the main content of microbial composition metabolism. This article will take you through how these amino acids are synthesized from simpler molecules and how they are classified. The biosynthesis of all amino acids is synthesized by branching pathways using intermediates of central metabolic pathways as precursors. According to the type of starting precursor, the biosynthesis of amino acids can be divided into 5 groups: Glutamate groups, including glutamate (Glu), glutamine (Gln), proline (Pro) and arginine (Arg). The synthesis of these amino acids begins with glutamate, a key molecule in a central metabolic pathway. The aspartate family includes aspartate (Asp), aspartamide (Asn), lysine (Lys), threonine (Thr), methionine (Met), and isoleucine (Ile). The amino acid synthesis of this family begins with aspartic acid, which is also a product of central metabolic pathways. Family of aromatic amino acids, including phenylalanine (Phe), tyrosine (Tyr), and tryptophan (Trp). The synthesis of these amino acids begins with erythrosis-4-phosphate (E4P) and phosphoenolpyruvate (PEP), two molecules that are also important intermediates in metabolic pathways. The serine family includes serine (Ser), glycine (Gly), and cysteine (Cys). The amino acid synthesis of this family begins with serine, which is the branching point of many biosynthetic pathways. The alanine group includes alanine (Ala), valine (Val) and leucine (Leu). Although these amino acids belong to different families, they have similar reactions during synthesis, and these reactions are usually catalyzed by the same class of enzymes.

Isoleucine, valine, and leucine, although belonging to different families, have similar reactions catalyzed by the same enzyme. Conversion of serine to cysteine is the main reaction of assimilative sulfate reduction. Biosynthesis of the aromatic amino acid group was initiated by erythrosis-4-P and PEP. The biosynthesis of histidine is special, and its carbon frame is derived from phosphoribose pyrophosphate (PRPP). Two C's in the ribose of PRPP are used to build the 5-membered imidazole ring, and the rest are used to create the 3C side chain. The biosynthesis of amino acids plays a key role in industrial fermentation. They are not only a fundamental component of microbial growth and metabolic activity, but also a key raw material for many fermented products. The production of amino acids by microbial fermentation can achieve efficient and low-cost production while reducing environmental pollution, which is crucial for food, feed, medicine and other industries.

In addition, the biosynthesis of amino acids has promoted the development of synthetic biology and metabolic engineering, making it possible to produce specific amino acids and their derivatives by microorganisms. This not only improves production efficiency, but also provides a platform for the development of new biotechnology products and further expands the application range of industrial fermentation.