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Systems metabolic engineering of Corynebacterium glutamicum for production of the chemical chaperone ectoine

BACKGROUND: The stabilizing and function-preserving effects of ectoines have attracted considerable biotechnological interest up to industrial scale processes for their production. These rely on the release of ectoines from high-salinity-cultivated microbial producer cells upon an osmotic down-shock...

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Autores principales: Becker, Judith, Schäfer, Rudolf, Kohlstedt, Michael, Harder, Björn J, Borchert, Nicole S, Stöveken, Nadine, Bremer, Erhard, Wittmann, Christoph
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4225761/
https://www.ncbi.nlm.nih.gov/pubmed/24228689
http://dx.doi.org/10.1186/1475-2859-12-110
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author Becker, Judith
Schäfer, Rudolf
Kohlstedt, Michael
Harder, Björn J
Borchert, Nicole S
Stöveken, Nadine
Bremer, Erhard
Wittmann, Christoph
author_facet Becker, Judith
Schäfer, Rudolf
Kohlstedt, Michael
Harder, Björn J
Borchert, Nicole S
Stöveken, Nadine
Bremer, Erhard
Wittmann, Christoph
author_sort Becker, Judith
collection PubMed
description BACKGROUND: The stabilizing and function-preserving effects of ectoines have attracted considerable biotechnological interest up to industrial scale processes for their production. These rely on the release of ectoines from high-salinity-cultivated microbial producer cells upon an osmotic down-shock in rather complex processor configurations. There is growing interest in uncoupling the production of ectoines from the typical conditions required for their synthesis, and instead design strains that naturally release ectoines into the medium without the need for osmotic changes, since the use of high-salinity media in the fermentation process imposes notable constraints on the costs, design, and durability of fermenter systems. RESULTS: Here, we used a Corynebacterium glutamicum strain as a cellular chassis to establish a microbial cell factory for the biotechnological production of ectoines. The implementation of a mutant aspartokinase enzyme ensured efficient supply of L-aspartate-beta-semialdehyde, the precursor for ectoine biosynthesis. We further engineered the genome of the basic C. glutamicum strain by integrating a codon-optimized synthetic ectABCD gene cluster under expressional control of the strong and constitutive C. glutamicum tuf promoter. The resulting recombinant strain produced ectoine and excreted it into the medium; however, lysine was still found as a by-product. Subsequent inactivation of the L-lysine exporter prevented the undesired excretion of lysine while ectoine was still exported. Using the streamlined cell factory, a fed-batch process was established that allowed the production of ectoine with an overall productivity of 6.7 g L(-1) day(-1) under growth conditions that did not rely on the use of high-salinity media. CONCLUSIONS: The present study describes the construction of a stable microbial cell factory for recombinant production of ectoine. We successfully applied metabolic engineering strategies to optimize its synthetic production in the industrial workhorse C. glutamicum and thereby paved the way for further improvements in ectoine yield and biotechnological process optimization.
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spelling pubmed-42257612014-11-12 Systems metabolic engineering of Corynebacterium glutamicum for production of the chemical chaperone ectoine Becker, Judith Schäfer, Rudolf Kohlstedt, Michael Harder, Björn J Borchert, Nicole S Stöveken, Nadine Bremer, Erhard Wittmann, Christoph Microb Cell Fact Research BACKGROUND: The stabilizing and function-preserving effects of ectoines have attracted considerable biotechnological interest up to industrial scale processes for their production. These rely on the release of ectoines from high-salinity-cultivated microbial producer cells upon an osmotic down-shock in rather complex processor configurations. There is growing interest in uncoupling the production of ectoines from the typical conditions required for their synthesis, and instead design strains that naturally release ectoines into the medium without the need for osmotic changes, since the use of high-salinity media in the fermentation process imposes notable constraints on the costs, design, and durability of fermenter systems. RESULTS: Here, we used a Corynebacterium glutamicum strain as a cellular chassis to establish a microbial cell factory for the biotechnological production of ectoines. The implementation of a mutant aspartokinase enzyme ensured efficient supply of L-aspartate-beta-semialdehyde, the precursor for ectoine biosynthesis. We further engineered the genome of the basic C. glutamicum strain by integrating a codon-optimized synthetic ectABCD gene cluster under expressional control of the strong and constitutive C. glutamicum tuf promoter. The resulting recombinant strain produced ectoine and excreted it into the medium; however, lysine was still found as a by-product. Subsequent inactivation of the L-lysine exporter prevented the undesired excretion of lysine while ectoine was still exported. Using the streamlined cell factory, a fed-batch process was established that allowed the production of ectoine with an overall productivity of 6.7 g L(-1) day(-1) under growth conditions that did not rely on the use of high-salinity media. CONCLUSIONS: The present study describes the construction of a stable microbial cell factory for recombinant production of ectoine. We successfully applied metabolic engineering strategies to optimize its synthetic production in the industrial workhorse C. glutamicum and thereby paved the way for further improvements in ectoine yield and biotechnological process optimization. BioMed Central 2013-11-15 /pmc/articles/PMC4225761/ /pubmed/24228689 http://dx.doi.org/10.1186/1475-2859-12-110 Text en Copyright © 2013 Becker et al.; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research
Becker, Judith
Schäfer, Rudolf
Kohlstedt, Michael
Harder, Björn J
Borchert, Nicole S
Stöveken, Nadine
Bremer, Erhard
Wittmann, Christoph
Systems metabolic engineering of Corynebacterium glutamicum for production of the chemical chaperone ectoine
title Systems metabolic engineering of Corynebacterium glutamicum for production of the chemical chaperone ectoine
title_full Systems metabolic engineering of Corynebacterium glutamicum for production of the chemical chaperone ectoine
title_fullStr Systems metabolic engineering of Corynebacterium glutamicum for production of the chemical chaperone ectoine
title_full_unstemmed Systems metabolic engineering of Corynebacterium glutamicum for production of the chemical chaperone ectoine
title_short Systems metabolic engineering of Corynebacterium glutamicum for production of the chemical chaperone ectoine
title_sort systems metabolic engineering of corynebacterium glutamicum for production of the chemical chaperone ectoine
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4225761/
https://www.ncbi.nlm.nih.gov/pubmed/24228689
http://dx.doi.org/10.1186/1475-2859-12-110
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