L-Threonine is a natural amino acid, can be produced by microbial fermentation, and is used in food, medicine, or feed[1].
References:
[1]. Zhao H, et al. Increasing L-threonine production in Escherichia coli by engineering the glyoxylate shunt and the L-threonine biosynthesis pathway. Appl Microbiol Biotechnol. 2018 Jul;102(13):5505-5518.
















