Coproduction of 5-Aminovalerate and δ-Valerolactam for the Synthesis of Nylon 5 From L-Lysine in Escherichia coli.

Jie Cheng,Zhou Luo,Li Liang,Guoqiang Zhang,Xinghua Gou,Wenying Tu,Xinhui Wang,Chao Liu

doi:10.3389/fbioe.2021.726126

Jie Cheng, Zhou Luo + Show 6 more

Open Access

https://doi.org/10.3389/fbioe.2021.726126

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Abstract

The compounds 5-aminovalerate and δ-valerolactam are important building blocks that can be used to synthesize bioplastics. The production of 5-aminovalerate and δ-valerolactam in microorganisms provides an ideal source that reduces the cost. To achieve efficient biobased coproduction of 5-aminovalerate and δ-valerolactam in Escherichia coli, a single biotransformation step from L-lysine was constructed. First, an equilibrium mixture was formed by L-lysine α-oxidase RaiP from Scomber japonicus. In addition, by adjusting the pH and H2O2 concentration, the titers of 5-aminovalerate and δ-valerolactam reached 10.24 and 1.82 g/L from 40 g/L L-lysine HCl at pH 5.0 and 10 mM H2O2, respectively. With the optimized pH value, the δ-valerolactam titer was improved to 6.88 g/L at pH 9.0 with a molar yield of 0.35 mol/mol lysine. The ratio of 5AVA and δ-valerolactam was obviously affected by pH value. The ratio of 5AVA and δ-valerolactam could be obtained in the range of 5.63:1–0.58:1 at pH 5.0–9.0 from the equilibrium mixture. As a result, the simultaneous synthesis of 5-aminovalerate and δ-valerolactam from L-lysine in Escherichia coli is highly promising. To our knowledge, this result constitutes the highest δ-valerolactam titer reported by biological methods. In summary, a commercially implied bioprocess developed for the coproduction of 5-aminovalerate and δ-valerolactam using engineered Escherichia coli.

Highlights

Over the years, mounting global environmental, climate change, economic concerns, and fossil fuel sources are leading to a shift in the production of traditional bulk chemicals toward more green, renewable, economic, and sustainable routes (Wang A. et al, 2020; Gordillo Sierra and Alper, 2020; Wendisch, 2020)
The designed route for the coproduction of 5AVA and δ-valerolactam consists of two steps: 1) the deamination of α-amino group in L-lysine to generate an equilibrium mixture by RaiP from S. japonicus, with this equilibrium mixture containing P2C, 2HP2C, 2P2C, 2K6AC, 6A2HH2E, and 6A2DHC; 2) the decarboxylation of 2K6AC, P2C, and 2P2C in this equilibrium mixture to produce 5AVA and δ-valerolactam via H2O2, respectively
The specific activity of RaiP was 5.14 units/mg. These results demonstrated the feasibility of the coproduction of 5AVA and δ-valerolactam in E. coli

Summary

Introduction

Over the years, mounting global environmental, climate change, economic concerns, and fossil fuel sources are leading to a shift in the production of traditional bulk chemicals toward more green, renewable, economic, and sustainable routes (Wang A. et al, 2020; Gordillo Sierra and Alper, 2020; Wendisch, 2020). Examples of these main platform chemicals range from succinate (Zhang et al, 2009), glutarate (Zhao et al, 2018), to adipate (Wang F. et al, 2020) for dicarboxylic acids; from putrescine, cadaverine (Rui et al, 2020; Xue et al, 2020), to 1,6-hexanediamine for diamines; from δ-valerolactam (Zhang et al, 2017a), to ε-caprolactam (Thompson et al, 2020) for lactams; from 3-hydroxybutyrate (Atakav et al, 2021; Mierziak et al, 2021; Schmid et al, 2021), 2hydroxybutyrate (Tian et al, 2021), to 3-hydroxyhexanoate (Harada et al, 2021) for hydroxyl acids; and from 4aminobutyrate, 5AVA (Cheng et al, 2021b), to 6aminocaproate (Turk et al, 2016) for ω-amino acids In this respect, 5AVA (Adkins et al, 2013) and δ-valerolactam (Xu et al, 2020) are attractive C5 platform chemicals for the production of biopolyamides from renewable biomass

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