» Articles » PMID: 21267412

Laboratory-evolved Mutants of an Exogenous Global Regulator, IrrE from Deinococcus Radiodurans, Enhance Stress Tolerances of Escherichia Coli

Overview
Journal PLoS One
Date 2011 Jan 27
PMID 21267412
Citations 26
Authors
Affiliations
Soon will be listed here.
Abstract

Background: The tolerance of cells toward different stresses is very important for industrial strains of microbes, but difficult to improve by the manipulation of single genes. Traditional methods for enhancing cellular tolerances are inefficient and time-consuming. Recently, approaches employing global transcriptional or translational engineering methods have been increasingly explored. We found that an exogenous global regulator, irrE from an extremely radiation-resistant bacterium, Deinococcus radiodurans, has the potential to act as a global regulator in Escherichia coli, and that laboratory-evolution might be applied to alter this regulator to elicit different phenotypes for E. coli.

Methodology/principal Findings: To extend the methodology for strain improvement and to obtain higher tolerances toward different stresses, we here describe an approach of engineering irrE gene in E. coli. An irrE library was constructed by randomly mutating the gene, and this library was then selected for tolerance to ethanol, butanol and acetate stresses. Several mutants showing significant tolerances were obtained and characterized. The tolerances of E. coli cells containing these mutants were enhanced 2 to 50-fold, based on cell growth tests using different concentrations of alcohols or acetate, and enhanced 10 to 100-fold based on ethanol or butanol shock experiments. Intracellular reactive oxygen species (ROS) assays showed that intracellular ROS levels were sharply reduced for cells containing the irrE mutants. Sequence analysis of the mutants revealed that the mutations distribute cross all three domains of the protein.

Conclusions: To our knowledge, this is the first time that an exogenous global regulator has been artificially evolved to suit its new host. The successes suggest the possibility of improving tolerances of industrial strains by introducing and engineering exogenous global regulators, such as those from extremophiles. This new approach can be applied alone or in combination with other global methods, such as global transcriptional machinery engineering (gTME) for strain improvements.

Citing Articles

Increasing the robustness of Escherichia coli for aromatic chemicals production through transcription factor engineering.

Zhou X, Zhang M, Zheng X, Zhang Z, Liu J Adv Biotechnol (Singap). 2025; 2(2):15.

PMID: 39883341 PMC: 11740835. DOI: 10.1007/s44307-024-00023-x.


Strategies to increase the robustness of microbial cell factories.

Xu P, Lin N, Zhang Z, Liu J Adv Biotechnol (Singap). 2025; 2(1):9.

PMID: 39883204 PMC: 11740849. DOI: 10.1007/s44307-024-00018-8.


Engineering quorum sensing-based genetic circuits enhances growth and productivity robustness of industrial E. coli at low pH.

Yan X, Bu A, Yuan Y, Zhang X, Lin Z, Yang X Microb Cell Fact. 2024; 23(1):256.

PMID: 39342182 PMC: 11438209. DOI: 10.1186/s12934-024-02524-9.


Advances in stress-tolerance elements for microbial cell factories.

Kuang Z, Yan X, Yuan Y, Wang R, Zhu H, Wang Y Synth Syst Biotechnol. 2024; 9(4):793-808.

PMID: 39072145 PMC: 11277822. DOI: 10.1016/j.synbio.2024.06.008.


A Rare Mono-Rhamnolipid Congener Efficiently Produced by Recombinant YM4 via the Expression of Global Transcriptional Regulator .

Wang X, Li D, Yue S, Yuan Z, Li S Molecules. 2024; 29(9).

PMID: 38731483 PMC: 11085080. DOI: 10.3390/molecules29091992.


References
1.
Cann M . A subset of GAF domains are evolutionarily conserved sodium sensors. Mol Microbiol. 2007; 64(2):461-72. DOI: 10.1111/j.1365-2958.2007.05669.x. View

2.
Atsumi S, Liao J . Metabolic engineering for advanced biofuels production from Escherichia coli. Curr Opin Biotechnol. 2008; 19(5):414-9. PMC: 2673505. DOI: 10.1016/j.copbio.2008.08.008. View

3.
Alper H, Moxley J, Nevoigt E, Fink G, Stephanopoulos G . Engineering yeast transcription machinery for improved ethanol tolerance and production. Science. 2006; 314(5805):1565-8. DOI: 10.1126/science.1131969. View

4.
Nicolaou S, Gaida S, Papoutsakis E . A comparative view of metabolite and substrate stress and tolerance in microbial bioprocessing: From biofuels and chemicals, to biocatalysis and bioremediation. Metab Eng. 2010; 12(4):307-31. DOI: 10.1016/j.ymben.2010.03.004. View

5.
Hua Y, Narumi I, Gao G, Tian B, Satoh K, Kitayama S . PprI: a general switch responsible for extreme radioresistance of Deinococcus radiodurans. Biochem Biophys Res Commun. 2003; 306(2):354-60. DOI: 10.1016/s0006-291x(03)00965-3. View