AUTHOR=Luo Zhou , Wang Zhen , Wang Bangxu , Lu Yao , Yan Lixiu , Zhao Zhiping , Bai Ting , Zhang Jiamin , Li Hanmei , Wang Wei , Cheng Jie 

TITLE=An Artificial Pathway for N-Hydroxy-Pipecolic Acid Production From L-Lysine in Escherichia coli

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.842804

DOI=10.3389/fmicb.2022.842804

ISSN=1664-302X

ABSTRACT=<p><italic>N</italic>-hydroxy-pipecolic acid (NHP) is a hydroxylated product of pipecolic acid and an important systemic acquired resistance signal molecule. However, the biosynthesis of NHP does not have a natural metabolic pathway in microorganisms. Here, we designed and constructed a promising artificial pathway in <italic>Escherichia coli</italic> for the first time to produce NHP from biomass-derived lysine. This biosynthesis route expands the lysine catabolism pathway and employs six enzymes to sequentially convert lysine into NHP. This artificial route involves six functional enzyme coexpression: lysine α-oxidase from <italic>Scomber japonicus</italic> (RaiP), glucose dehydrogenase from <italic>Bacillus subtilis</italic> (GDH), Δ<sup>1</sup>-piperideine-2-carboxylase reductase from <italic>Pseudomonas putida</italic> (DpkA), lysine permease from <italic>E. coli</italic> (LysP), flavin-dependent monooxygenase (FMO1), and catalase from <italic>E. coli</italic> (KatE). Moreover, different FMO1s are used to evaluate the performance of the produce NHP. A titer of 111.06 mg/L of NHP was yielded in shake flasks with minimal medium containing 4 g/L of lysine. By this approach, NHP has so far been produced at final titers reaching 326.42 mg/L by 48 h in a 5-L bioreactor. To the best of our knowledge, this is the first NHP process using <italic>E. coli</italic> and the first process to directly synthesize NHP by microorganisms. This study lays the foundation for the development and utilization of renewable resources to produce NHP in microorganisms.</p>