Application of Corynebacterium glutamicum in L- threonine biosynthesis

Abstract

L-threonine is an essential amino acid for human and animal nutrition. L-threonine is the second limiting amino acid in pig feed and the third limiting amino acid in poultry feed, primarily used as a feed additive. Currently, industrial production of L-threonine is achieved through fermentation using Escherichia coli. Corynebacterium glutamicum, a bacterium commonly used as an industrial production chassis for amino acids such as glutamic acid and L-lysine, possesses advantages such as biosafety and strong environmental adaptability. It is considered a potential strain for the efficient production of L-threonine. However, current production of L-threonine by C. glutamicum often leads to the accumulation of significant amounts of other amino acid by-products, limiting the level of L-threonine production. Previous studies that aimed to block or weaken the pathways for by-product synthesis resulted in strains with nutritional deficiencies or only partial reduction in by-product accumulation.