Production of dicarboxylates from ω-amino acids using a cofactor- and co-substrate-free in vitro biosynthetic system

Dicarboxylates are valuable platform compounds with a broad range of applications. The in vitro biosynthetic system used to produce dicarboxylates from ω-amino acids via the natural pathway requires costly cofactors and co-substrates, which restricts its economic feasibility of use. In this study, we designed a cofactor- and co-substrate-free artificial pathway for the production of dicarboxylates from ω-amino acids. Only three enzymes (viz., amine oxidase from Kluyveromyces marxianus DMKU3-1042, xanthine oxidase from bovine milk, and catalase from Aspergillus niger) were required for dicarboxylate production. Succinate (0.79 g g^-1), glutarate (0.83 g g^-1), and adipate (0.77 g g^-1) were produced in high yields from the corresponding ω-amino acids through the in vitro biosynthetic system with the artificial pathway. Glutarate could also be produced from l-lysine by further introducing l-lysine monooxygenase and 5-aminovaleramide amidohydrolase from Pseudomonas putida KT2440 into the in vitro biosynthetic system, with the cofactor- and co-substrate-free system achieving a product yield of 0.63 g g^-1. Considering its desirable characteristics, this artificial pathway-based in vitro biosynthetic system may be a promising alternative for dicarboxylate production from biotechnologically produced ω-amino acids.