PUMA publications for /tag/Pyruvatehttps://puma.ub.uni-stuttgart.de/tag/PyruvatePUMA RSS feed for /tag/Pyruvate2024-03-28T15:48:46+01:00L-valine production during growth of pyruvate dehydrogenase complex-deficient Corynebacterium glutamicum in the presence of ethanol or by inactivation of the transcriptional regulator SugRhttps://puma.ub.uni-stuttgart.de/bibtex/205af8a7b28d60ba8272685f0427eaadb/bastianbastian2018-02-09T13:18:17+01:00Complex Corynebacterium Dehydrogenase Ethanol, Factors, Gene Knockout Pyruvate Techniques, Transcription Valine, glutamicum, myown <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/1581b084966b1a19b10f06b5ed069aa58/author/0"><span itemprop="name">B. Blombach</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Annette Arndt" itemprop="url" href="/person/1581b084966b1a19b10f06b5ed069aa58/author/1"><span itemprop="name">A. Arndt</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Marc Auchter" itemprop="url" href="/person/1581b084966b1a19b10f06b5ed069aa58/author/2"><span itemprop="name">M. Auchter</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bernhard J. Eikmanns" itemprop="url" href="/person/1581b084966b1a19b10f06b5ed069aa58/author/3"><span itemprop="name">B. Eikmanns</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Appl. Environ. Microbiol.</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">75 </span></span>(<span itemprop="issueNumber">4</span>):
<span itemprop="pagination">1197--1200</span></em> </span>(<em><span>February 2009<meta content="February 2009" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018Appl. Environ. Microbiol.feb41197--1200L-valine production during growth of pyruvate dehydrogenase complex-deficient {Corynebacterium} glutamicum in the presence of ethanol or by inactivation of the transcriptional regulator {SugR}752009Complex Corynebacterium Dehydrogenase Ethanol, Factors, Gene Knockout Pyruvate Techniques, Transcription Valine, glutamicum, myown Pyruvate dehydrogenase complex-deficient strains of Corynebacterium glutamicum produce L-valine from glucose only after depletion of the acetate required for growth. Here we show that inactivation of the DeoR-type transcriptional regulator SugR or replacement of acetate by ethanol already in course of the growth phase results in efficient L-valine production.L-valine production with pyruvate dehydrogenase complex-deficient Corynebacterium glutamicumhttps://puma.ub.uni-stuttgart.de/bibtex/25bac540150e10acba07b2f8205f6f070/bastianbastian2018-02-09T13:18:17+01:00Acid, Alanine Complex, Corynebacterium Dehydrogenase Fermentation, Isoleucine, Lysine, Pyruvate Pyruvic Valine, glutamicum, myown <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/1d744d92c5af8f45409137c58d022ef1c/author/0"><span itemprop="name">B. Blombach</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Mark E. Schreiner" itemprop="url" href="/person/1d744d92c5af8f45409137c58d022ef1c/author/1"><span itemprop="name">M. Schreiner</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Jirí Holátko" itemprop="url" href="/person/1d744d92c5af8f45409137c58d022ef1c/author/2"><span itemprop="name">J. Holátko</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Tobias Bartek" itemprop="url" href="/person/1d744d92c5af8f45409137c58d022ef1c/author/3"><span itemprop="name">T. Bartek</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Marco Oldiges" itemprop="url" href="/person/1d744d92c5af8f45409137c58d022ef1c/author/4"><span itemprop="name">M. Oldiges</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bernhard J. Eikmanns" itemprop="url" href="/person/1d744d92c5af8f45409137c58d022ef1c/author/5"><span itemprop="name">B. Eikmanns</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Appl. Environ. Microbiol.</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">73 </span></span>(<span itemprop="issueNumber">7</span>):
<span itemprop="pagination">2079--2084</span></em> </span>(<em><span>April 2007<meta content="April 2007" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018Appl. Environ. Microbiol.apr72079--2084L-valine production with pyruvate dehydrogenase complex-deficient {Corynebacterium} glutamicum732007Acid, Alanine Complex, Corynebacterium Dehydrogenase Fermentation, Isoleucine, Lysine, Pyruvate Pyruvic Valine, glutamicum, myown Corynebacterium glutamicum was engineered for the production of L-valine from glucose by deletion of the aceE gene encoding the E1p enzyme of the pyruvate dehydrogenase complex and additional overexpression of the ilvBNCE genes encoding the L-valine biosynthetic enzymes acetohydroxyacid synthase, isomeroreductase, and transaminase B. In the absence of cellular growth, C. glutamicum DeltaaceE showed a relatively high intracellular concentration of pyruvate (25.9 mM) and produced significant amounts of pyruvate, L-alanine, and L-valine from glucose as the sole carbon source. Lactate or acetate was not formed. Plasmid-bound overexpression of ilvBNCE in C. glutamicum DeltaaceE resulted in an approximately 10-fold-lower intracellular pyruvate concentration (2.3 mM) and a shift of the extracellular product pattern from pyruvate and L-alanine towards L-valine. In fed-batch fermentations at high cell densities and an excess of glucose, C. glutamicum DeltaaceE(pJC4ilvBNCE) produced up to 210 mM L-valine with a volumetric productivity of 10.0 mM h(-1) (1.17 g l(-1) h(-1)) and a maximum yield of about 0.6 mol per mol (0.4 g per g) of glucose.Engineering Corynebacterium glutamicum for the production of 2,3-butanediolhttps://puma.ub.uni-stuttgart.de/bibtex/29ce34124eaffe2a799aade38deec413d/bastianbastian2018-02-09T13:18:17+01:00Bacterial Bioreactors, Butylene Complex, Corynebacterium Dehydrogenase Dehydrogenase, Engineering Family, Glucose, Glycols, L-Lactate Lactococcus Metabolic Multigene Oxygen, Proteins, Pyruvate glutamicum, lactis, myown <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Dušica Radoš" itemprop="url" href="/person/1518ec5750d920964df1a659788edff11/author/0"><span itemprop="name">D. Radoš</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Ana Lúcia Carvalho" itemprop="url" href="/person/1518ec5750d920964df1a659788edff11/author/1"><span itemprop="name">A. Carvalho</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Stefan Wieschalka" itemprop="url" href="/person/1518ec5750d920964df1a659788edff11/author/2"><span itemprop="name">S. Wieschalka</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Ana Rute Neves" itemprop="url" href="/person/1518ec5750d920964df1a659788edff11/author/3"><span itemprop="name">A. Neves</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/1518ec5750d920964df1a659788edff11/author/4"><span itemprop="name">B. Blombach</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bernhard J. Eikmanns" itemprop="url" href="/person/1518ec5750d920964df1a659788edff11/author/5"><span itemprop="name">B. Eikmanns</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Helena Santos" itemprop="url" href="/person/1518ec5750d920964df1a659788edff11/author/6"><span itemprop="name">H. Santos</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Microb. Cell Fact.</span>, </em> </span>(<em><span>October 2015<meta content="October 2015" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018Microb. Cell Fact.oct171Engineering {Corynebacterium} glutamicum for the production of 2,3-butanediol142015Bacterial Bioreactors, Butylene Complex, Corynebacterium Dehydrogenase Dehydrogenase, Engineering Family, Glucose, Glycols, L-Lactate Lactococcus Metabolic Multigene Oxygen, Proteins, Pyruvate glutamicum, lactis, myown BACKGROUND: 2,3-Butanediol is an important bulk chemical with a wide range of applications. In bacteria, this metabolite is synthesised from pyruvate via a three-step pathway involving α-acetolactate synthase, α-acetolactate decarboxylase and 2,3-butanediol dehydrogenase. Thus far, the best producers of 2,3-butanediol are pathogenic strains, hence, the development of more suitable organisms for industrial scale fermentation is needed. Herein, 2,3-butanediol production was engineered in the Generally Regarded As Safe (GRAS) organism Corynebacterium glutamicum. A two-stage fermentation process was implemented: first, cells were grown aerobically on acetate; in the subsequent production stage cells were used to convert glucose into 2,3-butanediol under non-growing and oxygen-limiting conditions.
RESULTS: A gene cluster, encoding the 2,3-butanediol biosynthetic pathway of Lactococcus lactis, was assembled and expressed in background strains, C. glutamicum ΔldhA, C. glutamicum ΔaceEΔpqoΔldhA and C. glutamicum ΔaceEΔpqoΔldhAΔmdh, tailored to minimize pyruvate-consuming reactions, i.e., to prevent carbon loss in lactic, acetic and succinic acids. Producer strains were characterized in terms of activity of the relevant enzymes in the 2,3-butanediol forming pathway, growth, and production of 2,3-butanediol under oxygen-limited conditions. Productivity was maximized by manipulating the aeration rate in the production phase. The final strain, C. glutamicum ΔaceEΔpqoΔldhAΔmdh(pEKEx2-als,aldB,Ptuf butA), under optimized conditions produced 2,3-butanediol with a 0.66 mol mol(-1) yield on glucose, an overall productivity of 0.2 g L(-1) h(-1) and a titer of 6.3 g L(-1).
CONCLUSIONS: We have successfully developed C. glutamicum into an efficient cell factory for 2,3-butanediol production. The use of the engineered strains as a basis for production of acetoin, a widespread food flavour, is proposed.Application of a genetically encoded biosensor for live cell imaging of L-valine production in pyruvate dehydrogenase complex-deficient Corynebacterium glutamicum strainshttps://puma.ub.uni-stuttgart.de/bibtex/29345950b723cb5b2b8e6a41af065cae9/bastianbastian2018-02-09T13:18:17+01:00Biosensing Complex, Corynebacterium Dehydrogenase Fluorescence, Microfluidics Online Phenotype, Pyruvate Systems, Techniques, Valine, glutamicum, myown <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Nurije Mustafi" itemprop="url" href="/person/15c2b0eaacc8d66ee79a8fdb8e64e9082/author/0"><span itemprop="name">N. Mustafi</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Alexander Grünberger" itemprop="url" href="/person/15c2b0eaacc8d66ee79a8fdb8e64e9082/author/1"><span itemprop="name">A. Grünberger</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Regina Mahr" itemprop="url" href="/person/15c2b0eaacc8d66ee79a8fdb8e64e9082/author/2"><span itemprop="name">R. Mahr</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Stefan Helfrich" itemprop="url" href="/person/15c2b0eaacc8d66ee79a8fdb8e64e9082/author/3"><span itemprop="name">S. Helfrich</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Katharina Nöh" itemprop="url" href="/person/15c2b0eaacc8d66ee79a8fdb8e64e9082/author/4"><span itemprop="name">K. Nöh</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/15c2b0eaacc8d66ee79a8fdb8e64e9082/author/5"><span itemprop="name">B. Blombach</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Dietrich Kohlheyer" itemprop="url" href="/person/15c2b0eaacc8d66ee79a8fdb8e64e9082/author/6"><span itemprop="name">D. Kohlheyer</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Julia Frunzke" itemprop="url" href="/person/15c2b0eaacc8d66ee79a8fdb8e64e9082/author/7"><span itemprop="name">J. Frunzke</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">PLoS ONE</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">9 </span></span>(<span itemprop="issueNumber">1</span>):
<span itemprop="pagination">e85731</span></em> </span>(<em><span>2014<meta content="2014" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018PLoS ONE1e85731Application of a genetically encoded biosensor for live cell imaging of {L}-valine production in pyruvate dehydrogenase complex-deficient {Corynebacterium} glutamicum strains92014Biosensing Complex, Corynebacterium Dehydrogenase Fluorescence, Microfluidics Online Phenotype, Pyruvate Systems, Techniques, Valine, glutamicum, myown The majority of biotechnologically relevant metabolites do not impart a conspicuous phenotype to the producing cell. Consequently, the analysis of microbial metabolite production is still dominated by bulk techniques, which may obscure significant variation at the single-cell level. In this study, we have applied the recently developed Lrp-biosensor for monitoring of amino acid production in single cells of gradually engineered L-valine producing Corynebacterium glutamicum strains based on the pyruvate dehydrogenase complex-deficient (PDHC) strain C. glutamicum ΔaceE. Online monitoring of the sensor output (eYFP fluorescence) during batch cultivation proved the sensor's suitability for visualizing different production levels. In the following, we conducted live cell imaging studies on C. glutamicum sensor strains using microfluidic chip devices. As expected, the sensor output was higher in microcolonies of high-yield producers in comparison to the basic strain C. glutamicum ΔaceE. Microfluidic cultivation in minimal medium revealed a typical Gaussian distribution of single cell fluorescence during the production phase. Remarkably, low amounts of complex nutrients completely changed the observed phenotypic pattern of all strains, resulting in a phenotypic split of the population. Whereas some cells stopped growing and initiated L-valine production, others continued to grow or showed a delayed transition to production. Depending on the cultivation conditions, a considerable fraction of non-fluorescent cells was observed, suggesting a loss of metabolic activity. These studies demonstrate that genetically encoded biosensors are a valuable tool for monitoring single cell productivity and to study the phenotypic pattern of microbial production strains.Corynebacterium glutamicum tailored for high-yield L-valine productionhttps://puma.ub.uni-stuttgart.de/bibtex/29723d6ce30daaf4910269ea54837c2d7/bastianbastian2018-02-09T13:18:17+01:00Bacterial Biomass, Biosynthetic Complex, Corynebacterium Dehydrogenase Engineering, Expression, Fermentation Gene Genetic Ketol-Acid Oxidoreductases, Pathways, Proteins, Pyruvate Reductoisomerase, Transaminases, Valine, glutamicum, myown <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/1e1d424fe4d9f617e1a0837a7567bea3a/author/0"><span itemprop="name">B. Blombach</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Mark E. Schreiner" itemprop="url" href="/person/1e1d424fe4d9f617e1a0837a7567bea3a/author/1"><span itemprop="name">M. Schreiner</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Tobias Bartek" itemprop="url" href="/person/1e1d424fe4d9f617e1a0837a7567bea3a/author/2"><span itemprop="name">T. Bartek</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Marco Oldiges" itemprop="url" href="/person/1e1d424fe4d9f617e1a0837a7567bea3a/author/3"><span itemprop="name">M. Oldiges</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bernhard J. Eikmanns" itemprop="url" href="/person/1e1d424fe4d9f617e1a0837a7567bea3a/author/4"><span itemprop="name">B. Eikmanns</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Appl. Microbiol. Biotechnol.</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">79 </span></span>(<span itemprop="issueNumber">3</span>):
<span itemprop="pagination">471--479</span></em> </span>(<em><span>June 2008<meta content="June 2008" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018Appl. Microbiol. Biotechnol.jun3471--479Corynebacterium glutamicum tailored for high-yield {L}-valine production792008Bacterial Biomass, Biosynthetic Complex, Corynebacterium Dehydrogenase Engineering, Expression, Fermentation Gene Genetic Ketol-Acid Oxidoreductases, Pathways, Proteins, Pyruvate Reductoisomerase, Transaminases, Valine, glutamicum, myown We recently engineered the wild type of Corynebacterium glutamicum for the growth-decoupled production of L: -valine from glucose by inactivation of the pyruvate dehydrogenase complex and additional overexpression of the ilvBNCE genes, encoding the L-valine biosynthetic enzymes acetohydroxyacid synthase, isomeroreductase, and transaminase B. Based on the first generation of pyruvate-dehydrogenase-complex-deficient C. glutamicum strains, a second generation of high-yield L-valine producers was constructed by successive deletion of the genes encoding pyruvate:quinone oxidoreductase, phosphoglucose isomerase, and pyruvate carboxylase and overexpression of ilvBNCE. In fed-batch fermentations at high cell densities, the newly constructed strains produced up to 410 mM (48 g/l) L-valine, showed a maximum yield of 0.75 to 0.86 mol/mol (0.49 to 0.56 g/g) of glucose in the production phase and, in contrast to the first generation strains, excreted neither pyruvate nor any other by-product tested.The pyruvate dehydrogenase complex of Corynebacterium glutamicum: an attractive target for metabolic engineeringhttps://puma.ub.uni-stuttgart.de/bibtex/2ed56a8ffa25fcb7fe239b276b7e52493/bastianbastian2018-02-09T13:18:17+01:00Acid, Amino Butanols, Complex, Corynebacterium Dehydrogenase Engineering, Isobutanol Metabolic Pyruvate Pyruvic Valine, acid and complex dehydrogenase engineering, glutamicum, myown organic production, <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bernhard J. Eikmanns" itemprop="url" href="/person/111bc42d6baae0b586acdbed655538eb6/author/0"><span itemprop="name">B. Eikmanns</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/111bc42d6baae0b586acdbed655538eb6/author/1"><span itemprop="name">B. Blombach</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">J. Biotechnol.</span>, </em> </span>(<em><span>December 2014<meta content="December 2014" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018J. Biotechnol.dec339--345The pyruvate dehydrogenase complex of {Corynebacterium} glutamicum: an attractive target for metabolic engineering192 Pt B2014Acid, Amino Butanols, Complex, Corynebacterium Dehydrogenase Engineering, Isobutanol Metabolic Pyruvate Pyruvic Valine, acid and complex dehydrogenase engineering, glutamicum, myown organic production, The pyruvate dehydrogenase complex (PDHC) catalyzes the oxidative thiamine pyrophosphate-dependent decarboxylation of pyruvate to acetyl-CoA and CO2. Since pyruvate is a key metabolite of the central metabolism and also the precursor for several relevant biotechnological products, metabolic engineering of this multienzyme complex is a promising strategy to improve microbial production processes. This review summarizes the current knowledge and achievements on metabolic engineering approaches to tailor the PDHC of Corynebacterium glutamicum for the bio-based production of l-valine, 2-ketosiovalerate, pyruvate, succinate and isobutanol and to improve l-lysine production.Platform engineering of Corynebacterium glutamicum with reduced pyruvate dehydrogenase complex activity for improved production of L-lysine, L-valine, and 2-ketoisovaleratehttps://puma.ub.uni-stuttgart.de/bibtex/2fc097b674eaff7966119cba97aaacd40/bastianbastian2018-02-09T13:18:17+01:00Acids, Biomass, Complex, Corynebacterium Dehydrogenase Deletion, Down-Regulation, Engineering Expression, Gene Genetic, Glucose, Keto Lysine, Metabolic Networks Pathways, Promoter Pyruvate Recombination, Regions, Valine, and glutamicum, myown <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Jens Buchholz" itemprop="url" href="/person/1671300cf6c01886cf28889b6f3b9a19e/author/0"><span itemprop="name">J. Buchholz</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Andreas Schwentner" itemprop="url" href="/person/1671300cf6c01886cf28889b6f3b9a19e/author/1"><span itemprop="name">A. Schwentner</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Britta Brunnenkan" itemprop="url" href="/person/1671300cf6c01886cf28889b6f3b9a19e/author/2"><span itemprop="name">B. Brunnenkan</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Christina Gabris" itemprop="url" href="/person/1671300cf6c01886cf28889b6f3b9a19e/author/3"><span itemprop="name">C. Gabris</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Simon Grimm" itemprop="url" href="/person/1671300cf6c01886cf28889b6f3b9a19e/author/4"><span itemprop="name">S. Grimm</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Robert Gerstmeir" itemprop="url" href="/person/1671300cf6c01886cf28889b6f3b9a19e/author/5"><span itemprop="name">R. Gerstmeir</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Ralf Takors" itemprop="url" href="/person/1671300cf6c01886cf28889b6f3b9a19e/author/6"><span itemprop="name">R. Takors</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bernhard J. Eikmanns" itemprop="url" href="/person/1671300cf6c01886cf28889b6f3b9a19e/author/7"><span itemprop="name">B. Eikmanns</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/1671300cf6c01886cf28889b6f3b9a19e/author/8"><span itemprop="name">B. Blombach</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Appl. Environ. Microbiol.</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">79 </span></span>(<span itemprop="issueNumber">18</span>):
<span itemprop="pagination">5566--5575</span></em> </span>(<em><span>September 2013<meta content="September 2013" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018Appl. Environ. Microbiol.sep185566--5575Platform engineering of {Corynebacterium} glutamicum with reduced pyruvate dehydrogenase complex activity for improved production of {L}-lysine, {L}-valine, and 2-ketoisovalerate792013Acids, Biomass, Complex, Corynebacterium Dehydrogenase Deletion, Down-Regulation, Engineering Expression, Gene Genetic, Glucose, Keto Lysine, Metabolic Networks Pathways, Promoter Pyruvate Recombination, Regions, Valine, and glutamicum, myown Exchange of the native Corynebacterium glutamicum promoter of the aceE gene, encoding the E1p subunit of the pyruvate dehydrogenase complex (PDHC), with mutated dapA promoter variants led to a series of C. glutamicum strains with gradually reduced growth rates and PDHC activities. Upon overexpression of the l-valine biosynthetic genes ilvBNCE, all strains produced l-valine. Among these strains, C. glutamicum aceE A16 (pJC4 ilvBNCE) showed the highest biomass and product yields, and thus it was further improved by additional deletion of the pqo and ppc genes, encoding pyruvate:quinone oxidoreductase and phosphoenolpyruvate carboxylase, respectively. In fed-batch fermentations at high cell densities, C. glutamicum aceE A16 Δpqo Δppc (pJC4 ilvBNCE) produced up to 738 mM (i.e., 86.5 g/liter) l-valine with an overall yield (YP/S) of 0.36 mol per mol of glucose and a volumetric productivity (QP) of 13.6 mM per h [1.6 g/(liter × h)]. Additional inactivation of the transaminase B gene (ilvE) and overexpression of ilvBNCD instead of ilvBNCE transformed the l-valine-producing strain into a 2-ketoisovalerate producer, excreting up to 303 mM (35 g/liter) 2-ketoisovalerate with a YP/S of 0.24 mol per mol of glucose and a QP of 6.9 mM per h [0.8 g/(liter × h)]. The replacement of the aceE promoter by the dapA-A16 promoter in the two C. glutamicum l-lysine producers DM1800 and DM1933 improved the production by 100\% and 44\%, respectively. These results demonstrate that C. glutamicum strains with reduced PDHC activity are an excellent platform for the production of pyruvate-derived products.Effect of pyruvate dehydrogenase complex deficiency on L-lysine production with Corynebacterium glutamicumhttps://puma.ub.uni-stuttgart.de/bibtex/2930ecfe113b73f241ab0452b05337d89/bastianbastian2018-02-09T13:18:17+01:00Bacterial, Base Biotechnology Complex, Corynebacterium DNA, Dehydrogenase Deletion, Expression, Fermentation, Gene Genes, Kinetics, Lysine, Pyruvate Sequence, glutamicum, myown <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/197097cd65b8e231a2578efbc7586a5dc/author/0"><span itemprop="name">B. Blombach</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Mark E. Schreiner" itemprop="url" href="/person/197097cd65b8e231a2578efbc7586a5dc/author/1"><span itemprop="name">M. Schreiner</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Matthias Moch" itemprop="url" href="/person/197097cd65b8e231a2578efbc7586a5dc/author/2"><span itemprop="name">M. Moch</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Marco Oldiges" itemprop="url" href="/person/197097cd65b8e231a2578efbc7586a5dc/author/3"><span itemprop="name">M. Oldiges</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bernhard J. Eikmanns" itemprop="url" href="/person/197097cd65b8e231a2578efbc7586a5dc/author/4"><span itemprop="name">B. Eikmanns</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Appl. Microbiol. Biotechnol.</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">76 </span></span>(<span itemprop="issueNumber">3</span>):
<span itemprop="pagination">615--623</span></em> </span>(<em><span>September 2007<meta content="September 2007" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018Appl. Microbiol. Biotechnol.sep3615--623Effect of pyruvate dehydrogenase complex deficiency on {L}-lysine production with {Corynebacterium} glutamicum762007Bacterial, Base Biotechnology Complex, Corynebacterium DNA, Dehydrogenase Deletion, Expression, Fermentation, Gene Genes, Kinetics, Lysine, Pyruvate Sequence, glutamicum, myown Intracellular precursor supply is a critical factor for amino acid productivity of Corynebacterium glutamicum. To test for the effect of improved pyruvate availability on L-lysine production, we deleted the aceE gene encoding the E1p enzyme of the pyruvate dehydrogenase complex (PDHC) in the L-lysine-producer C. glutamicum DM1729 and characterised the resulting strain DM1729-BB1 for growth and L-lysine production. Compared to the host strain, C. glutamicum DM1729-BB1 showed no PDHC activity, was acetate auxotrophic and, after complete consumption of the available carbon sources glucose and acetate, showed a more than 50\% lower substrate-specific biomass yield (0.14 vs 0.33 mol C/mol C), an about fourfold higher biomass-specific L-lysine yield (5.27 vs 1.23 mmol/g cell dry weight) and a more than 40\% higher substrate-specific L-lysine yield (0.13 vs 0.09 mol C/mol C). Overexpression of the pyruvate carboxylase or diaminopimelate dehydrogenase genes in C. glutamicum DM1729-BB1 resulted in a further increase in the biomass-specific L-lysine yield by 6 and 56\%, respectively. In addition to L-lysine, significant amounts of pyruvate, L-alanine and L-valine were produced by C. glutamicum DM1729-BB1 and its derivatives, suggesting a surplus of precursor availability and a further potential to improve L-lysine production by engineering the L-lysine biosynthetic pathway.RamB is an activator of the pyruvate dehydrogenase complex subunit E1p gene in Corynebacterium glutamicumhttps://puma.ub.uni-stuttgart.de/bibtex/2751d62556f83a4d54902c3b9fac85dfb/bastianbastian2018-02-09T13:18:17+01:00(Lipoamide) Acetates, Bacterial Bacterial, Base Corynebacterium Data, Dehydrogenase Expression Gene Molecular Proteins, Pyruvate Regulation, Sequence Sequence, glutamicum, myown <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/19f5f5ec2cc8c58eb2101574f015cd25b/author/0"><span itemprop="name">B. Blombach</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Annette Cramer" itemprop="url" href="/person/19f5f5ec2cc8c58eb2101574f015cd25b/author/1"><span itemprop="name">A. Cramer</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bernhard J. Eikmanns" itemprop="url" href="/person/19f5f5ec2cc8c58eb2101574f015cd25b/author/2"><span itemprop="name">B. Eikmanns</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Mark Schreiner" itemprop="url" href="/person/19f5f5ec2cc8c58eb2101574f015cd25b/author/3"><span itemprop="name">M. Schreiner</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">J. Mol. Microbiol. Biotechnol.</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">16 </span></span>(<span itemprop="issueNumber">3-4</span>):
<span itemprop="pagination">236--239</span></em> </span>(<em><span>2009<meta content="2009" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018J. Mol. Microbiol. Biotechnol.3-4236--239{RamB} is an activator of the pyruvate dehydrogenase complex subunit {E}1p gene in {Corynebacterium} glutamicum162009(Lipoamide) Acetates, Bacterial Bacterial, Base Corynebacterium Data, Dehydrogenase Expression Gene Molecular Proteins, Pyruvate Regulation, Sequence Sequence, glutamicum, myown In Corynebacterium glutamicum, the transcriptional regulator RamB negatively controls the expression of genes involved in acetate metabolism. Here we show that during growth in media containing glucose and in complex medium without glucose RamB activates expression of the aceE gene, encoding the E1p subunit of the pyruvate dehydrogenase complex. Thus, RamB functions both as repressor and as activator in C. glutamicum.Increased glucose utilization in Corynebacterium glutamicum by use of maltose, and its application for the improvement of L-valine productivityhttps://puma.ub.uni-stuttgart.de/bibtex/21df12e8a60a9e4096c1d87d23eeb3e5c/bastianbastian2018-02-09T13:18:17+01:00Bacterial Complex, Corynebacterium Dehydrogenase Glucose, Maltose, Phosphoenolpyruvate Phosphotransferase Proteins, Pyruvate Sugar System Valine, glutamicum, myown <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Felix S. Krause" itemprop="url" href="/person/1ad8f9fd57bd8d9502e4a4cb86d864384/author/0"><span itemprop="name">F. Krause</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Alexander Henrich" itemprop="url" href="/person/1ad8f9fd57bd8d9502e4a4cb86d864384/author/1"><span itemprop="name">A. Henrich</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/1ad8f9fd57bd8d9502e4a4cb86d864384/author/2"><span itemprop="name">B. Blombach</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Reinhard Krämer" itemprop="url" href="/person/1ad8f9fd57bd8d9502e4a4cb86d864384/author/3"><span itemprop="name">R. Krämer</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bernhard J. Eikmanns" itemprop="url" href="/person/1ad8f9fd57bd8d9502e4a4cb86d864384/author/4"><span itemprop="name">B. Eikmanns</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Gerd M. Seibold" itemprop="url" href="/person/1ad8f9fd57bd8d9502e4a4cb86d864384/author/5"><span itemprop="name">G. Seibold</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Appl. Environ. Microbiol.</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">76 </span></span>(<span itemprop="issueNumber">1</span>):
<span itemprop="pagination">370--374</span></em> </span>(<em><span>January 2010<meta content="January 2010" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018Appl. Environ. Microbiol.jan1370--374Increased glucose utilization in {Corynebacterium} glutamicum by use of maltose, and its application for the improvement of {L}-valine productivity762010Bacterial Complex, Corynebacterium Dehydrogenase Glucose, Maltose, Phosphoenolpyruvate Phosphotransferase Proteins, Pyruvate Sugar System Valine, glutamicum, myown Corynebacterium glutamicum efficiently utilizes maltose as a substrate. We show here that the presence of maltose increases glucose utilization by raising the expression of ptsG, which encodes the glucose-specific EII permease of the phosphotransferase system. Consequently, the L-valine productivity of a pyruvate dehydrogenase complex-deficient C. glutamicum strain was improved by the presence of maltose.Studies on substrate utilisation in L-valine-producing Corynebacterium glutamicum strains deficient in pyruvate dehydrogenase complexhttps://puma.ub.uni-stuttgart.de/bibtex/26cd66632a56fd528715fabdac1d8834b/bastianbastian2018-02-09T13:18:17+01:00Complex, Corynebacterium, Dehydrogenase Enhancement Genetic Pyruvate Species Specificity, Substrate Valine, myown <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Tobias Bartek" itemprop="url" href="/person/1d985c61ebf981af7bf8257c6c4ecb7c7/author/0"><span itemprop="name">T. Bartek</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Christiane Rudolf" itemprop="url" href="/person/1d985c61ebf981af7bf8257c6c4ecb7c7/author/1"><span itemprop="name">C. Rudolf</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Ulrike Kerssen" itemprop="url" href="/person/1d985c61ebf981af7bf8257c6c4ecb7c7/author/2"><span itemprop="name">U. Kerssen</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bianca Klein" itemprop="url" href="/person/1d985c61ebf981af7bf8257c6c4ecb7c7/author/3"><span itemprop="name">B. Klein</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/1d985c61ebf981af7bf8257c6c4ecb7c7/author/4"><span itemprop="name">B. Blombach</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Siegmund Lang" itemprop="url" href="/person/1d985c61ebf981af7bf8257c6c4ecb7c7/author/5"><span itemprop="name">S. Lang</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bernhard J. Eikmanns" itemprop="url" href="/person/1d985c61ebf981af7bf8257c6c4ecb7c7/author/6"><span itemprop="name">B. Eikmanns</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Marco Oldiges" itemprop="url" href="/person/1d985c61ebf981af7bf8257c6c4ecb7c7/author/7"><span itemprop="name">M. Oldiges</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Bioprocess Biosyst Eng</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">33 </span></span>(<span itemprop="issueNumber">7</span>):
<span itemprop="pagination">873--883</span></em> </span>(<em><span>September 2010<meta content="September 2010" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018Bioprocess Biosyst Engsep7873--883Studies on substrate utilisation in {L}-valine-producing {Corynebacterium} glutamicum strains deficient in pyruvate dehydrogenase complex332010Complex, Corynebacterium, Dehydrogenase Enhancement Genetic Pyruvate Species Specificity, Substrate Valine, myown The pyruvate dehydrogenase complex was deleted to increase precursor availability in Corynebacterium glutamicum strains overproducing L: -valine. The resulting auxotrophy is treated by adding acetate in addition glucose for growth, resulting in the puzzling fact of gluconeogenic growth with strongly reduced glucose uptake in the presence of acetate in the medium. This result was proven by intracellular metabolite analysis and labelling experiments. To increase productivity, the SugR protein involved in negative regulation of the phosphotransferase system, was inactivated, resulting in enhanced consumption of glucose. However, the surplus in substrate uptake was not converted to L-valine; instead, the formation of up to 289 microM xylulose was observed for the first time in C. glutamicum. As an alternative to the genetic engineering solution, a straightforward process engineering approach is proposed. Acetate limitation resulted in a more efficient use of acetate as cosubstrate, shown by an increased biomass yield Y(X/Ac) and improved L-valine formation.Comparative 13C metabolic flux analysis of pyruvate dehydrogenase complex-deficient, L-valine-producing Corynebacterium glutamicumhttps://puma.ub.uni-stuttgart.de/bibtex/287adbada4c59b528370d7ee2b0a038d6/bastianbastian2018-02-09T13:18:17+01:00Carbon Complex, Corynebacterium Dehydrogenase Dioxide, Escherichia Glycolysis, Isotopes, NADP Pathway, Pentose Phosphate Proteins, Pyruvate Transhydrogenases Valine, coli coli, glutamicum, myown <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Tobias Bartek" itemprop="url" href="/person/13db8757c79c2bbc557e709197512559c/author/0"><span itemprop="name">T. Bartek</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bastian Blombach" itemprop="url" href="/person/13db8757c79c2bbc557e709197512559c/author/1"><span itemprop="name">B. Blombach</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Siegmund Lang" itemprop="url" href="/person/13db8757c79c2bbc557e709197512559c/author/2"><span itemprop="name">S. Lang</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Bernhard J. Eikmanns" itemprop="url" href="/person/13db8757c79c2bbc557e709197512559c/author/3"><span itemprop="name">B. Eikmanns</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang Wiechert" itemprop="url" href="/person/13db8757c79c2bbc557e709197512559c/author/4"><span itemprop="name">W. Wiechert</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Marco Oldiges" itemprop="url" href="/person/13db8757c79c2bbc557e709197512559c/author/5"><span itemprop="name">M. Oldiges</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Katharina Nöh" itemprop="url" href="/person/13db8757c79c2bbc557e709197512559c/author/6"><span itemprop="name">K. Nöh</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Stephan Noack" itemprop="url" href="/person/13db8757c79c2bbc557e709197512559c/author/7"><span itemprop="name">S. Noack</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Appl. Environ. Microbiol.</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">77 </span></span>(<span itemprop="issueNumber">18</span>):
<span itemprop="pagination">6644--6652</span></em> </span>(<em><span>September 2011<meta content="September 2011" itemprop="datePublished"/></span></em>)</span>Fri Feb 09 13:18:17 CET 2018Appl. Environ. Microbiol.sep186644--6652Comparative 13C metabolic flux analysis of pyruvate dehydrogenase complex-deficient, {L}-valine-producing {Corynebacterium} glutamicum772011Carbon Complex, Corynebacterium Dehydrogenase Dioxide, Escherichia Glycolysis, Isotopes, NADP Pathway, Pentose Phosphate Proteins, Pyruvate Transhydrogenases Valine, coli coli, glutamicum, myown L-Valine can be formed successfully using C. glutamicum strains missing an active pyruvate dehydrogenase enzyme complex (PDHC). Wild-type C. glutamicum and four PDHC-deficient strains were compared by (13)C metabolic flux analysis, especially focusing on the split ratio between glycolysis and the pentose phosphate pathway (PPP). Compared to the wild type, showing a carbon flux of 69\% ± 14\% through the PPP, a strong increase in the PPP flux was observed in PDHC-deficient strains with a maximum of 113\% ± 22\%. The shift in the split ratio can be explained by an increased demand of NADPH for l-valine formation. In accordance, the introduction of the Escherichia coli transhydrogenase PntAB, catalyzing the reversible conversion of NADH to NADPH, into an L-valine-producing C. glutamicum strain caused the PPP flux to decrease to 57\% ± 6\%, which is below the wild-type split ratio. Hence, transhydrogenase activity offers an alternative perspective for sufficient NADPH supply, which is relevant for most amino acid production systems. Moreover, as demonstrated for L-valine, this bypass leads to a significant increase of product yield due to a concurrent reduction in carbon dioxide formation via the PPP.Evolution of pyruvate kinase-deficient Escherichia coli mutants enables
glycerol-based cell growth and succinate productionhttps://puma.ub.uni-stuttgart.de/bibtex/260e8ebd21cbf00b1cc6f966c45b8821b/siemannherzbergsiemannherzberg2018-01-25T13:38:08+01:00POMP carboxylase; deletion; evolution; gene kinase} metabolic myown pathway; phosphoenolpyruvate pyruvate rerouting; {flux <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="S. Soellner" itemprop="url" href="/person/19b52af74e04922f5a2cf6487da0f6070/author/0"><span itemprop="name">S. Soellner</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="M. Rahnert" itemprop="url" href="/person/19b52af74e04922f5a2cf6487da0f6070/author/1"><span itemprop="name">M. Rahnert</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="M. Siemann-Herzberg" itemprop="url" href="/person/19b52af74e04922f5a2cf6487da0f6070/author/2"><span itemprop="name">M. Siemann-Herzberg</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="R. Takors" itemprop="url" href="/person/19b52af74e04922f5a2cf6487da0f6070/author/3"><span itemprop="name">R. Takors</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="J. Altenbuchner" itemprop="url" href="/person/19b52af74e04922f5a2cf6487da0f6070/author/4"><span itemprop="name">J. Altenbuchner</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">JOURNAL OF APPLIED MICROBIOLOGY</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">115 </span></span>(<span itemprop="issueNumber">6</span>):
<span itemprop="pagination">1368-1378</span></em> </span>(<em><span>December 2013<meta content="December 2013" itemprop="datePublished"/></span></em>)</span>Thu Jan 25 13:38:08 CET 2018{111 RIVER ST, HOBOKEN 07030-5774, NJ USA}{JOURNAL OF APPLIED MICROBIOLOGY}{DEC}{6}{1368-1378}{Evolution of pyruvate kinase-deficient Escherichia coli mutants enables
glycerol-based cell growth and succinate production}{Article}{115}{2013}POMP carboxylase; deletion; evolution; gene kinase} metabolic myown pathway; phosphoenolpyruvate pyruvate rerouting; {flux {AimsThe aim of this study was to engineer Escherichia coli strains that
efficiently produce succinate from glycerol under anaerobic conditions
after an aerobic growth phase.
Methods and ResultsWe constructed E.coli strain ss195 with deletions of
pykA and pykF, which resulted in slow growth on glycerol as sole carbon
source. This growth defect was overcome by the selection of fast-growing
mutants. Whole-genome resequencing of the evolved mutant ss251
identified the mutation A595S in PEP carboxylase (Ppc). Reverse
metabolic engineering by introducing the wild-type allele revealed that
this mutation is crucial for the described phenotype. Strain ss251 and
derivatives thereof produced succinate with high yields above 80\%
molmol(-1) from glycerol under nongrowth conditions.
ConclusionsThe results show that during the aerobic growth of ss251, the
formation of pyruvate proceeds via the proposed POMP pathway, starting
with the carboxylation of PEP by Ppc. The resulting oxaloacetate is
reduced by malate dehydrogenase (Mdh) to malate, which is then
decarboxylated back to pyruvate by a malic enzyme (MaeA or MaeB).
Mutation of ppc is crucial for fast growth of pykAF mutants on glycerol.
Significance and Impact of StudyAn E.coli mutant that is capable of
achieving high yields of succinate (a top valued-added chemical) from
glycerol (an abundant carbon source) was constructed. The identified ppc
mutation could be applied to other production strains that require
strong PEP carboxylation fluxes.}