To successfully design expression systems for industrial biotechnology and biopharmaceutical applications; plasmid stability, efficient synthesis of the desired product and the use of selection markers acceptable to regulatory bodies are of utmost importance. In this work we demonstrate the application of a set of IPTG-inducible protein expression systems -- harboring different features namely, antibiotic vs auxotrophy marker; two-plasmids vs single plasmid expression system; expression levels of the repressor protein (LacI) and the auxotrophic marker (glyA) -- in high-cell density cultures to evaluate their suitability in bioprocess conditions that resemble industrial settings. Results revealed that the first generation of engineered strain showed a 50% reduction in the production of the model recombinant protein fuculose-1-phosphate aldolase (FucA) compared to the reference system from QIAGEN. The over-transcription of glyA was found to be a major factor responsible for the metabolic burden. The second- and third-generation of expression systems presented an increase in FucA production and advantageous features. In particular, the third-generation expression system is antibiotic-free, autotrophy-selection based and single-plasmid and, is capable to produce FucA at similar levels compared to the original commercial expression system. These new tools open new avenues for high-yield and robust expression of recombinant proteins in E. coli.
|Number of pages||11|
|Journal||Journal of Industrial Microbiology & Biotechnology|
|Early online date||3 Jun 2022|
|Publication status||Published - Jul 2022|
Bibliographical note© The Author(s) 2022. Published by Oxford University Press on behalf of Society of Industrial Microbiology and Biotechnology. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
Funding: This work was supported by the Spanish MICINN, project number
CTQ2011-28398-CO2-01, the research group 2009SGR281, and by the Bioprocess Engineering and Applied Biocatalisys Group, Department of Chemical, Biological and Environmental Engineering of the Universitat Autònoma de Barcelona, Cerdanyola del Valles (Spain)
- Anti-Bacterial Agents/metabolism
- Batch Cell Culture Techniques
- Escherichia coli/genetics
- Fructose-Bisphosphate Aldolase/genetics
- Recombinant Proteins/metabolism