Efficient production of the Nylon 12 monomer ω-aminododecanoic acid methyl ester from renewable dodecanoic acid methyl ester with engineered Escherichia coli

Journal
Metabolic engineering  
Volume
36
Start Page
1
End Page
9
Citation
Metabolic Engineering (36): 1-9 (2016-07-01)
Publisher DOI
10.1016/j.ymben.2016.02.011
Scopus ID
2-s2.0-84960900554
The expansion of microbial substrate and product scopes will be an important brick promoting future bioeconomy. In this study, an orthogonal pathway running in parallel to native metabolism and converting renewable dodecanoic acid methyl ester (DAME) via terminal alcohol and aldehyde to 12-aminododecanoic acid methyl ester (ADAME), a building block for the high-performance polymer Nylon 12, was engineered in Escherichia coli and optimized regarding substrate uptake, substrate requirements, host strain choice, flux, and product yield. Efficient DAME uptake was achieved by means of the hydrophobic outer membrane porin AlkL increasing maximum oxygenation and transamination activities 8.3 and 7.6-fold, respectively. An optimized coupling to the pyruvate node via a heterologous alanine dehydrogenase enabled efficient intracellular L-alanine supply, a prerequisite for self-sufficient whole-cell transaminase catalysis. Finally, the introduction of a respiratory chain-linked alcohol dehydrogenase enabled an increase in pathway flux, the minimization of undesired overoxidation to the respective carboxylic acid, and thus the efficient formation of ADAME as main product. The completely synthetic orthogonal pathway presented in this study sets the stage for Nylon 12 production from renewables. Its effective operation achieved via fine tuning the connectivity to native cell functionalities emphasizes the potential of this concept to expand microbial substrate and product scopes.
Subjects
Dodecanedioic acid monomethyl ester (PubChem CID: 231998)
In vivo cascade biocatalysis
Methyl 12-aminododecanoate (PubChem CID: 3665980)
Methyl 12-hydroxydodecanoate (PubChem CID: 522424)
Methyl dodecanoate (PubChem CID: 8139)
Nylon 12
Orthogonal pathway engineering
Renewable plastics
Substrate uptake