Production of L-tryptophan by Microbial Fermentation

L-tryptophan is one of the eight amino acids necessary for human and animal life activities. It cannot be naturally synthesized in the human body and must be taken from food. It exists in the living body in a free state or in a living state. It plays a very important role in the physiological activities of animal growth, metabolism and so on. It is called the second essential amino acid and is widely used in food, feed and medical industry. L-tryptophan production methods are chemical synthesis, conversion and microbial fermentation. In recent years, with the successful use of metabolic engineering in the breeding of tryptophan bacteria, microbial fermentation has gradually become the main method of production of tryptophan. The metabolic engineering strategies involved in the production of tryptophan by microbial fermentation were reviewed, including the mechanism of metabolic regulation of biotinylated tryptophan and the measures and eff ects of pathway modifi cation. In addition, the future development of L-tryptophan was also discussed.