Metabolic engineering combined with site-directed saturated mutations of α-keto acid decarboxylase for efficient production of 6-aminocaproic acid and 1,6-hexamethylenediamine.

Autor: Wang T; Innovation Center for Textile Science and Technology, College of Biological Science and Medical Engineering, Donghua University, Shanghai, People's Republic of China., Ye P; Innovation Center for Textile Science and Technology, College of Biological Science and Medical Engineering, Donghua University, Shanghai, People's Republic of China., Xu X; Innovation Center for Textile Science and Technology, College of Biological Science and Medical Engineering, Donghua University, Shanghai, People's Republic of China., Lu M; Innovation Center for Textile Science and Technology, College of Biological Science and Medical Engineering, Donghua University, Shanghai, People's Republic of China., Zhang X; Innovation Center for Textile Science and Technology, College of Biological Science and Medical Engineering, Donghua University, Shanghai, People's Republic of China., Li N; Innovation Center for Textile Science and Technology, College of Biological Science and Medical Engineering, Donghua University, Shanghai, People's Republic of China.
Jazyk: angličtina
Zdroj: Biotechnology and bioengineering [Biotechnol Bioeng] 2024 Oct; Vol. 121 (10), pp. 3329-3337. Date of Electronic Publication: 2024 Jul 02.
DOI: 10.1002/bit.28795
Abstrakt: 6-Aminocaproic acid (6ACA) and 1,6-hexamethylenediamine (HMDA) are key precursors for nylon synthesis, and both are produced using petroleum-based chemical processes. However, the utilization of bio-based raw materials for biological production of monomers is crucial for nylon industry. In this study, we demonstrated that metabolic engineering of Escherichia coli and selected mutations of α-keto acid decarboxylase successfully synthesized 6ACA and HMDA. An artificial iterative cycle from l-lysine to chain-extended α-ketoacids was introduced into Escherichia coli BL21 (DE3). Then, the extended α-ketoacids were decarboxylated and oxidized for 6ACA production. Overexpression of catalase (KatE) combined with the site-directed mutations of α-isopropylmalate synthase (LeuA) contributed synergistic enhancement effect on synthesis of 6ACA, resulting in a 1.3-fold increase in 6ACA titer. Selected mutations in α-keto acid decarboxylase (KivD) improved its specificity and 170.00 ± 5.57 mg/L of 6ACA with a yield of 0.13 mol/mol (6ACA/l-lysine hydrochloride) was achieved by shake flask cultivation of the engineered strain with the KivD# (F381Y/V461I). Meanwhile, the engineered E. coli could accumulate 84.67 ± 4.04 mg/L of HMDA with a yield of 0.08 mol/mol (HMDA/l-lysine hydrochloride) by replacing aldehyde dehydrogenase with bi-aminotransferases. This achievement marks a significant advancement in the biological synthesis of 6-carbon compounds, since the biosynthetic pathways of HMDA are rarely identified.
(© 2024 Wiley Periodicals LLC.)
Databáze: MEDLINE
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