Creating Polyploid Escherichia Coli and Its Application in Efficient L‐Threonine Production

Abstract

Prokaryotic genomes are generally organized in haploid. In synthetic biological research, efficient chassis cells must be constructed to produce bio‐based products. Here, the essential division of the ftsZ gene to create functional polyploid E. coli is regulated. The artificial polyploid E. coli containing 2–4 chromosomes is confirmed through PCR amplification, terminator localization, and flow cytometry. The polyploid E. coli exhibits a larger cell size, and its low pH tolerance and acetate resistance are stronger than those of haploid E. coli. Transcriptome analysis shows that the genes of the cell's main functional pathways are significantly upregulated in the polyploid E. coli. These advantages of the polyploid E. coli results in the highest reported L‐threonine yield (160.3 g L−1) in fed‐batch fermentation to date. In summary, an easy and convenient method for constructing polyploid E. coli and demonstrated its application in L‐threonine production is developed. This work provides a new approach for creating an excellent host strain for biochemical production and studying the evolution of prokaryotes and their chromosome functions.

Recent Advances in Metabolic Engineering for the Biosynthesis of Phosphoenol Pyruvate–Oxaloacetate–Pyruvate-Derived Amino Acids

“…Currently, the strategy for producing L-Thr via metabolic engineering of E. coli and C. glutamicum is primarily divided into the following points: (1) modification of the core biosynthetic pathway, (2) elimination of by-products, (3) transport engineering, (4) dynamic regulation of metabolic pathways (e.g., POP node and operon), and (5) system metabolic engineering. Notably, Liang et al employed system metabolic engineering to significantly enhance the production of L-Thr in E. coli , achieving the highest reported yield thus far [ 73 ]. The following subsections detail the specific research progress in L-Thr production using these two types of engineered bacteria.…”

“…Notably, the genes encoding the cell’s core functional pathways exhibit significant upregulation, contributing to the strain’s remarkable performance. These advancements have culminated in the achievement of the highest L-threonine yield reported thus far, attaining a yield of 160.3 g/L in fed-batch fermentation [ 73 ], marking a significant milestone in metabolic engineering.…”

Engineering an Artificial Pathway to Improve the Bioconversion of Lysine into Chiral Amino Alcohol 2-Hydroxycadaverine Using a Semi-Rational Design

“…The core of synthetic biology is to reshape natural biological systems to produce natural or non-natural chemicals [1,2]. Recently many important high-value chemicals have been produced in microorganisms via synthetic biology, such as L-pipecolic acid [3], rosmarinic acid [4], pigments [5], caffeic acid [6], 5-hydroxyectoine [7], quercetin [8], 2-keto-L-gulonic acid [9], ergothioneine [10], monoterpene [11], ectoine [12], and glutarate [13].…”