Application of fermentation process control to increase <scp>l</scp>‐tryptophan production in <scp><i>Escherichia coli</i></scp>

Zhao, Chenyang; Fang, Haitian; Jing, Wang; Zhang, Shasha; Zhao, Xiubao; Li, Zengliang; Chao, Lin; Shen, Zhiqiang; Cheng, Likun

doi:10.1002/btpr.2944

Cited by 12 publications

(6 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Possible modifications to improve L-tryptophan producer strains have been previously summarised by [18,20,[22][23][24][25][26]. High L-tryptophan concentrations of 48.68 g L −1 with glucose as carbon source were reported with rationally engineered E. coli strains [23], and increased titres of 52.57 g L −1 were reached in combination with adapted pH and dissolved oxygen control strategies in the fed-batch process [27]. Aside from high product concentrations, the economic efficiency of production processes is also dependent on substrate conversion rates and the current market values of the carbon sources used.…”

Section: Introductionmentioning

confidence: 99%

Metabolic control analysis of L-tryptophan producing Escherichia coli applying targeted perturbation with shikimate

Schoppel

Trachtmann

Mittermeier

et al. 2021

Bioprocess Biosyst Eng

View full text Add to dashboard Cite

L-tryptophan production from glycerol with Escherichia coli was analysed by perturbation studies and metabolic control analysis. The insertion of a non-natural shikimate transporter into the genome of an Escherichia coli L-tryptophan production strain enabled targeted perturbation within the product pathway with shikimate during parallelised short-term perturbation experiments with cells withdrawn from a 15 L fed-batch production process. Expression of the shikimate/H+-symporter gene (shiA) from Corynebacterium glutamicum did not alter process performance within the estimation error. Metabolic analyses and subsequent extensive data evaluation were performed based on the data of the parallel analysis reactors and the production process. Extracellular rates and intracellular metabolite concentrations displayed evident deflections in cell metabolism and particularly in chorismate biosynthesis due to the perturbations with shikimate. Intracellular flux distributions were estimated using a thermodynamics-based flux analysis method, which integrates thermodynamic constraints and intracellular metabolite concentrations to restrain the solution space. Feasible flux distributions, Gibbs reaction energies and concentration ranges were computed simultaneously for the genome-wide metabolic model, with minimum bias in relation to the direction of metabolic reactions. Metabolic control analysis was applied to estimate elasticities and flux control coefficients, predicting controlling sites for L-tryptophan biosynthesis. The addition of shikimate led to enhanced deviations in chorismate biosynthesis, revealing a so far not observed control of 3-dehydroquinate synthase on L-tryptophan formation. The relative expression of the identified target genes was analysed with RT-qPCR. Transcriptome analysis revealed disparities in gene expression and the localisation of target genes to further improve the microbial L-tryptophan producer by metabolic engineering.

show abstract

Section: Introductionmentioning

confidence: 99%

Metabolic control analysis of L-tryptophan producing Escherichia coli applying targeted perturbation with shikimate

Schoppel

Trachtmann

Mittermeier

et al. 2021

Bioprocess Biosyst Eng

View full text Add to dashboard Cite

show abstract

“…Based on the law of conservation and the pseudo‐steady‐state hypothesis (PSSH) of intracellular intermediate metabolites, a mass metabolic matrix was constructed 28 . A stoichiometric model was assumed to describe the metabolic network of E. coli for L‐threonine production and was constructed on the basis of five assumptions: 23 (a) Cell growth was negligible during the later phase of fermentation; (b) The glyoxylate shunt was considered inactive; (c) There was no transhydrogenase for the interconversion of NADPH and NADH; (d) The stoichiometric matrix was simplified by lumping adjacent reactions lacking branch pathways; and (e) The consumption energy and the maintenance energy were not equivalent due to too much futile energy during the non‐growth period.…”

Section: Methodsmentioning

confidence: 99%

“…The DO, pH, and temperature were automatically measured with electrodes attached to the fermenters. The cell density was measured using a spectrophotometer at 600 nm (OD 600 ), and the OD 600 values and biomass (dry cell weight, DCW) of E. coli were assumed related as: 1 OD 600 = 0.42 g L −1 DCW 28 . The concentration of L‐threonine in the fermentation broth was determined by high‐pressure liquid chromatography using an Agilent 1200 instrument (Agilent Technologies, Santa Clara, CA) 23 .…”

Section: Methodsmentioning

confidence: 99%

“…The cell density was measured using a spectrophotometer at 600 nm (OD 600 ), and the OD 600 values and biomass (dry cell weight, DCW) of E. coli were assumed related as: 1 OD 600 = 0.42 g L −1 DCW. 28 The concentration of L-threonine in the fermentation broth was determined by high-pressure liquid chromatography using an Agilent 1200 instrument (Agilent Technologies, Santa Clara, CA). 23 The concentration of glucose was monitored using an SBA-40 E biosensor analyzer (Biology Institute of Shandong Academy of Sciences, Jinan, China).…”

Section: Analysis Of Fermentation Productsmentioning

confidence: 99%

“…The stoichiometric equations and the algebraic equations of metabolic nodes are as previously described,2,23 and are provided in Supplemental File 1. Analysis of metabolic flux balance was performed using the stoichiometry model for the strain in stationary phase during the end of the fermentation period, and the metabolic flux distribution for threonine biosynthesis by this strain was calculated using MATLAB (MathWorks, Natick, USA) 28,29.…”

mentioning

confidence: 99%

See 2 more Smart Citations

An antiphage Escherichia coli mutant for higher production of L‐threonine obtained by atmospheric and room temperature plasma mutagenesis

Cheng¹,

Wang

Zhao³

et al. 2020

Biotechnology Progress

Self Cite

View full text Add to dashboard Cite

Phage infection is common during the production of L-threonine by E. coli, and low L-threonine production and glucose conversion percentage are bottlenecks for the efficient commercial production of L-threonine. In this study, 20 antiphage mutants producing high concentration of L-threonine were obtained by atmospheric and room temperature plasma (ARTP) mutagenesis, and an antiphage E. coli variant was characterized that exhibited the highest production of L-threonine Escherichia coli ([E. coli] TRFC-AP). The elimination of fhuA expression in E. coli TRFC-AP was responsible for phage resistance. The biomass and cell growth of E. coli TRFC-AP showed no significant differences from those of the parent strain (E. coli TRFC), and the production of L-threonine (159.3 g L −1) and glucose conversion percentage (51.4%) were increased by 10.9% and 9.1%, respectively, compared with those of E. coli TRFC. During threonine production (culture time of 20 h), E. coli TRFC-AP exhibited higher activities of key enzymes for glucose utilization (hexokinase, glucose phosphate dehydrogenase, phosphofructokinase, phosphoenolpyruvate carboxylase, and PYK) and threonine synthesis (glutamate synthase, aspartokinase, homoserine dehydrogenase, homoserine kinase and threonine synthase) compared to those of E. coli TRFC. The analysis of metabolic flux distribution indicated that the flux of threonine with E. coli TRFC-AP reached 69.8%, an increase of 16.0% compared with that of E. coli TRFC. Overall, higher L-threonine production and glucose conversion percentage were obtained with E. coli TRFC-AP due to increased activities of key enzymes and improved carbon flux for threonine synthesis.

show abstract

Application of a dissolved oxygen control strategy to increase the expression of Streptococcus suis glutamate dehydrogenase in Escherichia coli

Cheng¹,

Zhao

Yang

et al. 2021

World J Microbiol Biotechnol

View full text Add to dashboard Cite

Application of fermentation process control to increase l‐tryptophan production in Escherichia coli

Cited by 12 publications

References 34 publications

Metabolic control analysis of L-tryptophan producing Escherichia coli applying targeted perturbation with shikimate

Metabolic control analysis of L-tryptophan producing Escherichia coli applying targeted perturbation with shikimate

An antiphage Escherichia coli mutant for higher production of L‐threonine obtained by atmospheric and room temperature plasma mutagenesis

Application of a dissolved oxygen control strategy to increase the expression of Streptococcus suis glutamate dehydrogenase in Escherichia coli

Contact Info

Product

Resources

About