scholarly journals A constraint-based modeling approach to reach an improved chemically defined minimal medium for recombinant antiEpEX-scFv production by Escherichia coli

Author(s):  
Aidin Behravan ◽  
atieh hashemi ◽  
Sayed-Amir Marashi

Increasing demand for recombinant therapeutic proteins highlights the necessity of their yield improvement. Culture medium formulation is a popular approach for bioprocess optimization to improve therapeutic protein production. Constraint-based modeling can empower high-precision optimization through information on how media compounds affect metabolism and cell growth. In the current study, a genome-scale metabolic model (GEMM) of Escherichia coli cells was employed to design strategies of minimal medium supplementation for higher antiEpEX-scFv production. Dynamic flux balance analysis of the recombinant E. coli cell model predicted that ammonium was depleted during the process. Based on the simulations, three amino acids (Asn, Gln and Arg) were chosen to be added to the medium to compensate for ammonium depletion. Experimental validation suggested that the addition of these amino acids (one-by-one, or in combinations) can indeed improve cell growth and recombinant protein production. Then, design of experiment was used to optimize the concentrations of amino acids in the growth medium. About two-fold increase in the growth rate and total scFv expression level was observed using this strategy. We conclude that the GEMM-based approach can provide insights into an effective feeding strategy to improve the production of recombinant protein in E. coli.

2019 ◽  
Vol 116 (6) ◽  
pp. 1259-1268 ◽  
Author(s):  
Martin Lemmerer ◽  
Juergen Mairhofer ◽  
Alexander Lepak ◽  
Karin Longus ◽  
Rainer Hahn ◽  
...  

2020 ◽  
Vol 9 (11) ◽  
pp. 3052-3066
Author(s):  
Meritxell Galindo Casas ◽  
Patrick Stargardt ◽  
Juergen Mairhofer ◽  
Birgit Wiltschi

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Qin Fan ◽  
Peter Neubauer ◽  
Matthias Gimpel

Abstract Background Autoinduction systems can regulate protein production in Escherichia coli without the need to monitor cell growth or add inducer at the proper time following culture growth. Compared to classical IPTG induction, autoinduction provides a simple and fast way to obtain high protein yields. In the present study, we report on the optimization process for the enhanced heterologous production of the Ralstonia eutropha regulatory hydrogenase (RH) in E. coli using autoinduction. These autoinduction methods were combined with the EnPresso B fed-batch like growth system, which applies slow in situ enzymatic glucose release from a polymer to control cell growth and protein synthesis rate. Results We were able to produce 125 mg L−1 RH corresponding to a productivity averaged over the whole process time of 3 mg (L h)−1 in shake flasks using classic single-shot IPTG induction. IPTG autoinduction resulted in a comparable volumetric RH yield of 112 mg L−1 and due to the shorter overall process time in a 1.6-fold higher productivity of 5 mg (L h)−1. In contrast, lactose autoinduction increased the volumetric yield more than 2.5-fold and the space time yield fourfold reaching 280 mg L−1 and 11.5 mg (L h)−1, respectively. Furthermore, repeated addition of booster increased RH production to 370 mg L−1, which to our knowledge is the highest RH concentration produced in E. coli to date. Conclusions The findings of this study confirm the general feasibility of the developed fed-batch based autoinduction system and provide an alternative to conventional induction systems for efficient recombinant protein production. We believe that the fed-batch based autoinduction system developed herein will favor the heterologous production of larger quantities of difficult-to-express complex enzymes to enable economical production of these kinds of proteins.


2020 ◽  
Author(s):  
Luciana C. Gomes ◽  
Gabriel A. Monteiro ◽  
Filipe J. Mergulhão

<p><em>Escherichia coli</em> biofilms have a great biotechnological potential since this organism has been one of the preferred hosts for recombinant protein production for the past decades and it has been successfully used in metabolic engineering for the production of high-value compounds.</p> <p>In a previous study, we have demonstrated that the non-induced enhanced green fluorescent protein (eGFP) expression from <em>E. coli</em> biofilm cells was 30-fold higher than in the planktonic state without any optimization of cultivation parameters [1]. The aim of the present work was to evaluate the effect of chemical induction with isopropyl β-D-1-thiogalactopyranoside (IPTG) on the expression of eGFP by planktonic and biofilm cells of <em>E. coli</em> JM109(DE3) transformed with a plasmid containing a T7 promoter.</p> <p>It was shown that induction negatively affected the growth and viability of planktonic cultures, and eGFP production did not increase. Recombinant protein production was not limited by gene dosage or by transcriptional activity. Results suggest that plasmid maintenance at high copy number imposes a metabolic burden that precludes high level expression of the recombinant protein. In biofilm cells, the inducer avoided the overall decrease in the amount of expressed eGFP, although this was not correlated with the gene dosage. Higher specific production levels were always attained with biofilm cells and it seems that while induction of biofilm cells shifts their metabolism towards the maintenance of recombinant protein concentration, in planktonic cells the cellular resources are directed towards plasmid replication and growth [2].</p> <p>It is expected that this work will be of great value to elucidate the mechanisms of induction on recombinant protein production, especially in biofilm cells which have shown potential to be used as protein factories.</p> <p> </p> <p> </p> <p>References:</p> <p>[1] Gomes, L.C., & Mergulhão, F.J. (2017) Heterologous protein production in <em>Escherichia coli</em> biofilms: A non-conventional form of high cell density cultivation. <em>Process Biochemistry, 57, 1-8</em>. https://doi.org/10.1016/j.procbio.2017.03.018</p> <p>[2] Gomes, L., Monteiro, G., & Mergulhão, F. (2020). The Impact of IPTG Induction on Plasmid Stability and Heterologous Protein Expression by <em>Escherichia coli</em> Biofilms. <em>International Journal of Molecular Sciences, 21(2), 576</em>. https://doi.org/10.3390/ijms21020576</p>


Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 414 ◽  
Author(s):  
Hao Chen ◽  
Sumana Venkat ◽  
Jessica Wilson ◽  
Paige McGuire ◽  
Abigail Chang ◽  
...  

Recombinant protein production plays an essential role in both biological studies and pharmaceutical production. Escherichia coli is one of the most favorable hosts for this purpose. Although a number of strategies for optimizing protein production have been developed, the effect of gene overexpression on host cell growth has been much less studied. Here, we performed high-throughput tests on the E. coli a complete set of E. coli K-12 ORF archive (ASKA) collection to quantify the effects of overexpressing individual E. coli genes on its growth. The results indicated that overexpressing membrane-associated proteins or proteins with high abundances of branched-chain amino acids tended to impair cell growth, the latter of which could be remedied by amino acid supplementation. Through this study, we expect to provide an index for a fast pre-study estimate of host cell growth in order to choose proper rescuing approaches when working with different proteins.


2009 ◽  
Vol 75 (16) ◽  
pp. 5424-5427 ◽  
Author(s):  
Niju Narayanan ◽  
C. Perry Chou

ABSTRACT Two amino acids, Leu149 and Val223, were identified as proteolytically sensitive when Pseudozyma antarctica lipase (PalB) was heterologously expressed in Escherichia coli. The functional expression was enhanced using the double mutant for cultivation. However, the recombinant protein production was still limited by PalB misfolding, which was resolved by DsbA coexpression.


2021 ◽  
Vol 12 ◽  
Author(s):  
Gema Lozano Terol ◽  
Julia Gallego-Jara ◽  
Rosa Alba Sola Martínez ◽  
Adrián Martínez Vivancos ◽  
Manuel Cánovas Díaz ◽  
...  

Recombinant protein production for medical, academic, or industrial applications is essential for our current life. Recombinant proteins are obtained mainly through microbial fermentation, with Escherichia coli being the host most used. In spite of that, some problems are associated with the production of recombinant proteins in E. coli, such as the formation of inclusion bodies, the metabolic burden, or the inefficient translocation/transport system of expressed proteins. Optimizing transcription of heterologous genes is essential to avoid these drawbacks and develop competitive biotechnological processes. Here, expression of YFP reporter protein is evaluated under the control of four promoters of different strength (PT7lac, Ptrc, Ptac, and PBAD) and two different replication origins (high copy number pMB1′ and low copy number p15A). In addition, the study has been carried out with the E. coli BL21 wt and the ackA mutant strain growing in a rich medium with glucose or glycerol as carbon sources. Results showed that metabolic burden associated with transcription and translation of foreign genes involves a decrease in recombinant protein expression. It is necessary to find a balance between plasmid copy number and promoter strength to maximize soluble recombinant protein expression. The results obtained represent an important advance on the most suitable expression system to improve both the quantity and quality of recombinant proteins in bioproduction engineering.


2020 ◽  
Author(s):  
Artur Schuller ◽  
Monika Cserjan-Puschmann ◽  
Christopher Tauer ◽  
Johanna Jarmer ◽  
Martin Wagenknecht ◽  
...  

Abstract Background The genome-integrated T7 expression system offers significant advantages, in terms of productivity and product quality, even when expressing the gene of interest (GOI) from a single copy of. Compared to plasmid-based expression systems, this system does not incur a plasmid-mediated metabolic load, and it does not vary the dosage of the GOI during the production process. However, long-term production with T7 expression system leads to a rapidly growing non-producing population, because the T7 RNA polymerase (RNAP) is prone to mutations. The present study aimed to investigate whether two σ 70 promoters, which were recognized by the Escherichia coli host RNAP, might be suitable in genome-integrated expression systems. We applied a promoter engineering strategy that allowed control of expressing the model protein, GFP, by introducing lac operators ( lacO ) into the constitutive T5 and A1 promoter sequences. Results We showed that, in genome-integrated E. coli expression systems that used σ 70 promoters, the number of lacO sites must be well balanced. Promoters containing three and two lacO sites exhibited low basal expression, but resulted in a complete stop in recombinant protein production in partially induced cultures. In contrast, expression systems regulated by a single lacO site and the lac repressor element, lacI Q , on the same chromosome caused very low basal expression, were highly efficient in recombinant protein production, and enables fine-tuning of gene expression levels on a cellular level. Conclusions Based on our results, we hypothesized that this phenomenon was associated with the autoregulation of the lac repressor protein, LacI. We reasoned that the affinity of LacI for the lacO sites of the GOI must be lower than the affinity of LacI to the lacO sites of the endogenous lac operon; otherwise, LacI autoregulation could not take place, and the lack of LacI autoregulation would lead to a disturbance in lac repressor-mediated regulation of transcription. By exploiting the mechanism of LacI autoregulation, we created a novel E. coli expression system for use in recombinant protein production, synthetic biology, and metabolic engineering applications.


2019 ◽  
Author(s):  
Artur Schuller ◽  
Monika Cserjan-Puschmann ◽  
Christopher Tauer ◽  
Johanna Jarmer ◽  
Martin Wagenknecht ◽  
...  

Abstract Background The genome-integrated T7 expression system offers significant advantages, in terms of productivity and product quality, even when expressing the gene of interest (GOI) from a single copy of. Compared to plasmid-based expression systems, this system does not incur a plasmid-mediated metabolic load, and it does not vary the dosage of the GOI during the production process. However, long-term production with T7 expression system leads to a rapidly growing non-producing population, because the T7 RNA polymerase (RNAP) is prone to mutations. The present study aimed to investigate whether two σ 70 promoters, which were recognized by the Escherichia coli host RNAP, might be suitable in genome-integrated expression systems. We applied a promoter engineering strategy that allowed control of expressing the model protein, GFP, by introducing lac operators ( lacO ) into the constitutive T5 and A1 promoter sequences.Results We showed that, in genome-integrated E. coli expression systems that used σ 70 promoters, the number of lacO sites must be well balanced. Promoters containing three and two lacO sites exhibited low basal expression, but resulted in a complete stop in recombinant protein production in partially induced cultures. In contrast, expression systems regulated by a single lacO site and the lac repressor element, lacI Q , on the same chromosome caused very low basal expression, were highly efficient in recombinant protein production, and enables fine-tuning of gene expression levels on a cellular level.Conclusions Based on our results, we hypothesized that this phenomenon was associated with the autoregulation of the lac repressor protein, LacI. We reasoned that the affinity of LacI for the lacO sites of the GOI must be lower than the affinity of LacI to the lacO sites of the endogenous lac operon; otherwise, LacI autoregulation could not take place, and the lack of LacI autoregulation would lead to a disturbance in lac repressor-mediated regulation of transcription. By exploiting the mechanism of LacI autoregulation, we created a novel E. coli expression system for use in recombinant protein production, synthetic biology, and metabolic engineering applications.


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