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Significantly improved solvent tolerance of Escherichia coli by global transcription machinery engineering.

Zhang F, Qian X, Si H, Xu G, Han R, Ni Y - Microb. Cell Fact. (2015)

Bottom Line: The rpoD mutant contains three amino-acid substitutes and a stop-codon mutation, resulting a truncated sequence containing regions σ(1.1) and σ(1.2).Our results show that several genes (gapA, sdhB, pepB and dppA) play critical roles in enhanced solvent tolerance of E. coli, mainly involving in maintaining higher intracellular energy level under solvent stress.Global transcription machinery engineering is therefore a feasible and efficient approach for engineering strain with enhanced OST-phenotype.

View Article: PubMed Central - PubMed

Affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 214122, Wuxi, Jiangsu, China. zf23.32@163.com.

ABSTRACT

Background: Escherichia coli has emerged as a promising platform microorganism to produce biofuels and fine chemicals of industrial interests. Certain obstacles however remain to be overcome, among which organic-solvent tolerance is a crucial one.

Results: We used global transcription machinery engineering (gTME) to improve the organic-solvent tolerance (OST) of E. coli JM109. A mutant library of σ(70) encoded by rpoD was screened under cyclohexane pressure. E. coli JM109 strain harboring σ(70) mutant C9 was identified with capability of tolerating 69 % cyclohexane. The rpoD mutant contains three amino-acid substitutes and a stop-codon mutation, resulting a truncated sequence containing regions σ(1.1) and σ(1.2). Total protein difference produced by E. coli JM109 strain harboring C9 was examined with 2D-PAGE, and 204 high-abundant proteins showed over twofold variation under different solvent stress.

Conclusions: Our results show that several genes (gapA, sdhB, pepB and dppA) play critical roles in enhanced solvent tolerance of E. coli, mainly involving in maintaining higher intracellular energy level under solvent stress. Global transcription machinery engineering is therefore a feasible and efficient approach for engineering strain with enhanced OST-phenotype.

No MeSH data available.


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Genetic composition of σ70 WT and C9
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Fig5: Genetic composition of σ70 WT and C9

Mentions: There are 7 σ factors (σ70, σ54, σ32, σS, σE, σF and σFecI) in E. coli, and σ70 is the main control factor that is responsible for the transcription of over 1000 genes. σ70 consists of 4 parts, namely σ1 (region 1.1), σ2 (region 1.2 and region 2), σ3 (region 3) and σ4 (region 4). In 2007, Alper and Stephanopoulos generated σ70 mutant gene which retained only σ4 region to enhance the ethanol tolerance of E. coli [21]. In 2008, Yu and coworkers isolated σ70 mutant comprised of only σ1 and σ2 for enhanced hyaluronic acid accumulation [22]. In this study, a truncated mutation also occurred in rpoD mutant C9, remaining regions σ1.1and σ1.2 (Fig. 5). Our results indicate that a truncated mutation in rpoD may markedly change cell phenotype such as OST by regulating the transcription of a number of related genes.Fig. 5


Significantly improved solvent tolerance of Escherichia coli by global transcription machinery engineering.

Zhang F, Qian X, Si H, Xu G, Han R, Ni Y - Microb. Cell Fact. (2015)

Genetic composition of σ70 WT and C9
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4635540&req=5

Fig5: Genetic composition of σ70 WT and C9
Mentions: There are 7 σ factors (σ70, σ54, σ32, σS, σE, σF and σFecI) in E. coli, and σ70 is the main control factor that is responsible for the transcription of over 1000 genes. σ70 consists of 4 parts, namely σ1 (region 1.1), σ2 (region 1.2 and region 2), σ3 (region 3) and σ4 (region 4). In 2007, Alper and Stephanopoulos generated σ70 mutant gene which retained only σ4 region to enhance the ethanol tolerance of E. coli [21]. In 2008, Yu and coworkers isolated σ70 mutant comprised of only σ1 and σ2 for enhanced hyaluronic acid accumulation [22]. In this study, a truncated mutation also occurred in rpoD mutant C9, remaining regions σ1.1and σ1.2 (Fig. 5). Our results indicate that a truncated mutation in rpoD may markedly change cell phenotype such as OST by regulating the transcription of a number of related genes.Fig. 5

Bottom Line: The rpoD mutant contains three amino-acid substitutes and a stop-codon mutation, resulting a truncated sequence containing regions σ(1.1) and σ(1.2).Our results show that several genes (gapA, sdhB, pepB and dppA) play critical roles in enhanced solvent tolerance of E. coli, mainly involving in maintaining higher intracellular energy level under solvent stress.Global transcription machinery engineering is therefore a feasible and efficient approach for engineering strain with enhanced OST-phenotype.

View Article: PubMed Central - PubMed

Affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 214122, Wuxi, Jiangsu, China. zf23.32@163.com.

ABSTRACT

Background: Escherichia coli has emerged as a promising platform microorganism to produce biofuels and fine chemicals of industrial interests. Certain obstacles however remain to be overcome, among which organic-solvent tolerance is a crucial one.

Results: We used global transcription machinery engineering (gTME) to improve the organic-solvent tolerance (OST) of E. coli JM109. A mutant library of σ(70) encoded by rpoD was screened under cyclohexane pressure. E. coli JM109 strain harboring σ(70) mutant C9 was identified with capability of tolerating 69 % cyclohexane. The rpoD mutant contains three amino-acid substitutes and a stop-codon mutation, resulting a truncated sequence containing regions σ(1.1) and σ(1.2). Total protein difference produced by E. coli JM109 strain harboring C9 was examined with 2D-PAGE, and 204 high-abundant proteins showed over twofold variation under different solvent stress.

Conclusions: Our results show that several genes (gapA, sdhB, pepB and dppA) play critical roles in enhanced solvent tolerance of E. coli, mainly involving in maintaining higher intracellular energy level under solvent stress. Global transcription machinery engineering is therefore a feasible and efficient approach for engineering strain with enhanced OST-phenotype.

No MeSH data available.


Related in: MedlinePlus