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Schmollack M, Werner F, Huber J, Kiefer D, Merkel M, Hausmann R, Siebert D, Blombach B. Metabolic engineering of Corynebacterium glutamicum for acetate-based itaconic acid production. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:139. [PMID: 36517879 PMCID: PMC9753420 DOI: 10.1186/s13068-022-02238-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 12/04/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Itaconic acid is a promising platform chemical for a bio-based polymer industry. Today, itaconic acid is biotechnologically produced with Aspergillus terreus at industrial scale from sugars. The production of fuels but also of chemicals from food substrates is a dilemma since future processes should rely on carbon sources which do not compete for food or feed. Therefore, the production of chemicals from alternative substrates such as acetate is desirable to develop novel value chains in the bioeconomy. RESULTS In this study, Corynebacterium glutamicum ATCC 13032 was engineered to efficiently produce itaconic acid from the non-food substrate acetate. Therefore, we rewired the central carbon and nitrogen metabolism by inactivating the transcriptional regulator RamB, reducing the activity of isocitrate dehydrogenase, deletion of the gdh gene encoding glutamate dehydrogenase and overexpression of cis-aconitate decarboxylase (CAD) from A. terreus optimized for expression in C. glutamicum. The final strain C. glutamicum ΔramB Δgdh IDHR453C (pEKEx2-malEcadopt) produced 3.43 ± 0.59 g itaconic acid L-1 with a product yield of 81 ± 9 mmol mol-1 during small-scale cultivations in nitrogen-limited minimal medium containing acetate as sole carbon and energy source. Lowering the cultivation temperature from 30 °C to 25 °C improved CAD activity and further increased the titer and product yield to 5.01 ± 0.67 g L-1 and 116 ± 15 mmol mol-1, respectively. The latter corresponds to 35% of the theoretical maximum and so far represents the highest product yield for acetate-based itaconic acid production. Further, the optimized strain C. glutamicum ΔramB Δgdh IDHR453C (pEKEx2-malEcadopt), produced 3.38 ± 0.28 g itaconic acid L-1 at 25 °C from an acetate-containing aqueous side-stream of fast pyrolysis. CONCLUSION As shown in this study, acetate represents a suitable non-food carbon source for itaconic acid production with C. glutamicum. Tailoring the central carbon and nitrogen metabolism enabled the efficient production of itaconic acid from acetate and therefore this study offers useful design principles to genetically engineer C. glutamicum for other products from acetate.
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Affiliation(s)
- Marc Schmollack
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Uferstraße 53, 94315, Straubing, Germany
| | - Felix Werner
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Uferstraße 53, 94315, Straubing, Germany
| | - Janine Huber
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Uferstraße 53, 94315, Straubing, Germany
| | - Dirk Kiefer
- Institute of Food Science and Biotechnology, Department of Bioprocess Engineering, University of Hohenheim, Stuttgart, Germany
| | - Manuel Merkel
- Institute of Food Science and Biotechnology, Department of Bioprocess Engineering, University of Hohenheim, Stuttgart, Germany
| | - Rudolf Hausmann
- Institute of Food Science and Biotechnology, Department of Bioprocess Engineering, University of Hohenheim, Stuttgart, Germany
| | - Daniel Siebert
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Uferstraße 53, 94315, Straubing, Germany
- SynBiofoundry@TUM, Technical University of Munich, Straubing, Germany
| | - Bastian Blombach
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Uferstraße 53, 94315, Straubing, Germany.
- SynBiofoundry@TUM, Technical University of Munich, Straubing, Germany.
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Feierabend M, Renz A, Zelle E, Nöh K, Wiechert W, Dräger A. High-Quality Genome-Scale Reconstruction of Corynebacterium glutamicum ATCC 13032. Front Microbiol 2021; 12:750206. [PMID: 34867870 PMCID: PMC8634658 DOI: 10.3389/fmicb.2021.750206] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 10/19/2021] [Indexed: 11/30/2022] Open
Abstract
Corynebacterium glutamicum belongs to the microbes of enormous biotechnological relevance. In particular, its strain ATCC 13032 is a widely used producer of L-amino acids at an industrial scale. Its apparent robustness also turns it into a favorable platform host for a wide range of further compounds, mainly because of emerging bio-based economies. A deep understanding of the biochemical processes in C. glutamicum is essential for a sustainable enhancement of the microbe's productivity. Computational systems biology has the potential to provide a valuable basis for driving metabolic engineering and biotechnological advances, such as increased yields of healthy producer strains based on genome-scale metabolic models (GEMs). Advanced reconstruction pipelines are now available that facilitate the reconstruction of GEMs and support their manual curation. This article presents iCGB21FR, an updated and unified GEM of C. glutamicum ATCC 13032 with high quality regarding comprehensiveness and data standards, built with the latest modeling techniques and advanced reconstruction pipelines. It comprises 1042 metabolites, 1539 reactions, and 805 genes with detailed annotations and database cross-references. The model validation took place using different media and resulted in realistic growth rate predictions under aerobic and anaerobic conditions. The new GEM produces all canonical amino acids, and its phenotypic predictions are consistent with laboratory data. The in silico model proved fruitful in adding knowledge to the metabolism of C. glutamicum: iCGB21FR still produces L-glutamate with the knock-out of the enzyme pyruvate carboxylase, despite the common belief to be relevant for the amino acid's production. We conclude that integrating high standards into the reconstruction of GEMs facilitates replicating validated knowledge, closing knowledge gaps, and making it a useful basis for metabolic engineering. The model is freely available from BioModels Database under identifier MODEL2102050001.
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Affiliation(s)
- Martina Feierabend
- Computational Systems Biology of Infections and Antimicrobial-Resistant Pathogens, Institute for Bioinformatics and Medical Informatics (IBMI), University of Tübingen, Tübingen, Germany
- Department of Computer Science, University of Tübingen, Tübingen, Germany
| | - Alina Renz
- Computational Systems Biology of Infections and Antimicrobial-Resistant Pathogens, Institute for Bioinformatics and Medical Informatics (IBMI), University of Tübingen, Tübingen, Germany
- Department of Computer Science, University of Tübingen, Tübingen, Germany
| | - Elisabeth Zelle
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Katharina Nöh
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Wolfgang Wiechert
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
- Computational Systems Biotechnology (AVT.CSB), RWTH Aachen University, Aachen, Germany
| | - Andreas Dräger
- Computational Systems Biology of Infections and Antimicrobial-Resistant Pathogens, Institute for Bioinformatics and Medical Informatics (IBMI), University of Tübingen, Tübingen, Germany
- Department of Computer Science, University of Tübingen, Tübingen, Germany
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Change in Cofactor Specificity of Oxidoreductases by Adaptive Evolution of an Escherichia coli NADPH-Auxotrophic Strain. mBio 2021; 12:e0032921. [PMID: 34399608 PMCID: PMC8406311 DOI: 10.1128/mbio.00329-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The nicotinamide cofactor specificity of enzymes plays a key role in regulating metabolic processes and attaining cellular homeostasis. Multiple studies have used enzyme engineering tools or a directed evolution approach to switch the cofactor preference of specific oxidoreductases. However, whole-cell adaptation toward the emergence of novel cofactor regeneration routes has not been previously explored. To address this challenge, we used an Escherichia coli NADPH-auxotrophic strain. We continuously cultivated this strain under selective conditions. After 500 to 1,100 generations of adaptive evolution using different carbon sources, we isolated several strains capable of growing without an external NADPH source. Most isolated strains were found to harbor a mutated NAD+-dependent malic enzyme (MaeA). A single mutation in MaeA was found to switch cofactor specificity while lowering enzyme activity. Most mutated MaeA variants also harbored a second mutation that restored the catalytic efficiency of the enzyme. Remarkably, the best MaeA variants identified this way displayed overall superior kinetics relative to the wild-type variant with NAD+. In other evolved strains, the dihydrolipoamide dehydrogenase (Lpd) was mutated to accept NADP+, thus enabling the pyruvate dehydrogenase and 2-ketoglutarate dehydrogenase complexes to regenerate NADPH. Interestingly, no other central metabolism oxidoreductase seems to evolve toward reducing NADP+, which we attribute to several biochemical constraints, including unfavorable thermodynamics. This study demonstrates the potential and biochemical limits of evolving oxidoreductases within the cellular context toward changing cofactor specificity, further showing that long-term adaptive evolution can optimize enzyme activity beyond what is achievable via rational design or directed evolution using small libraries.
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Stella RG, Wiechert J, Noack S, Frunzke J. Evolutionary engineering of
Corynebacterium glutamicum. Biotechnol J 2019; 14:e1800444. [DOI: 10.1002/biot.201800444] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/23/2019] [Indexed: 01/02/2023]
Affiliation(s)
- Roberto G. Stella
- Institute of Bio‐ and Geosciences, IBG‐1: Biotechnology, Forschungszentrum Jülich Wilhelm‐Johnen‐Straße 52428 Jülich Germany
| | - Johanna Wiechert
- Institute of Bio‐ and Geosciences, IBG‐1: Biotechnology, Forschungszentrum Jülich Wilhelm‐Johnen‐Straße 52428 Jülich Germany
| | - Stephan Noack
- Institute of Bio‐ and Geosciences, IBG‐1: Biotechnology, Forschungszentrum Jülich Wilhelm‐Johnen‐Straße 52428 Jülich Germany
| | - Julia Frunzke
- Institute of Bio‐ and Geosciences, IBG‐1: Biotechnology, Forschungszentrum Jülich Wilhelm‐Johnen‐Straße 52428 Jülich Germany
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Yoon J, Woo HM. CRISPR interference-mediated metabolic engineering of Corynebacterium glutamicum for homo-butyrate production. Biotechnol Bioeng 2018; 115:2067-2074. [PMID: 29704438 DOI: 10.1002/bit.26720] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 04/20/2018] [Accepted: 04/25/2018] [Indexed: 02/02/2023]
Abstract
Combinatorial metabolic engineering enabled the development of efficient microbial cell factories for modulating gene expression to produce desired products. Here, we report the combinatorial metabolic engineering of Corynebacterium glutamicum to produce butyrate by introducing a synthetic butyrate pathway including phosphotransferase and butyrate kinase reactions and repressing the essential acn gene-encoding aconitase, which has been targeted for downregulation in a genome-scale model. An all-in-one clustered regularly interspaced short palindromic repeats interference system for C. glutamicum was used for tunable downregulation of acn in an engineered strain, where by-product-forming reactions were deleted and the synthetic butyrate pathway was inserted, resulting in butyrate production (0.52 ± 0.02 g/L). Subsequently, biotin limitation enabled the engineered strain to produce butyrate (0.58 ± 0.01 g/L) without acetate formation for the entire duration of the culture. These results demonstrate the potential homo-production of butyrate using engineered C. glutamicum. This method can also be applied to other industrial microorganisms.
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Affiliation(s)
- Jinkyung Yoon
- Department of Food Science and Biotechnology, Sungkyunkwan University (SKKU), Suwon, Republic of Korea
| | - Han Min Woo
- Department of Food Science and Biotechnology, Sungkyunkwan University (SKKU), Suwon, Republic of Korea
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Schwentner A, Feith A, Münch E, Busche T, Rückert C, Kalinowski J, Takors R, Blombach B. Metabolic engineering to guide evolution – Creating a novel mode for L-valine production with Corynebacterium glutamicum. Metab Eng 2018. [DOI: 10.1016/j.ymben.2018.02.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Zhao M, Lu X, Zong H, Li J, Zhuge B. Itaconic acid production in microorganisms. Biotechnol Lett 2018; 40:455-464. [DOI: 10.1007/s10529-017-2500-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 12/19/2017] [Indexed: 01/19/2023]
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Balado M, Puentes B, Couceiro L, Fuentes-Monteverde JC, Rodríguez J, Osorio CR, Jiménez C, Lemos ML. Secreted Citrate Serves as Iron Carrier for the Marine Pathogen Photobacterium damselae subsp damselae. Front Cell Infect Microbiol 2017; 7:361. [PMID: 28848719 PMCID: PMC5550697 DOI: 10.3389/fcimb.2017.00361] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/26/2017] [Indexed: 12/03/2022] Open
Abstract
Photobacterium damselae subsp damselae (Pdd) is a Vibrionaceae that has a wide pathogenic potential against many marine animals and also against humans. Some strains of this bacterium acquire iron through the siderophore vibrioferrin. However, there are virulent strains that do not produce vibrioferrin, but they still give a strong positive reaction in the CAS test for siderophore production. In an in silico search on the genome sequences of this type of strains we could not find any ORF which could be related to a siderophore system. To identify genes that could encode a siderophore-mediated iron acquisition system we used a mini-Tn10 transposon random mutagenesis approach. From more than 1,400 mutants examined, we could isolate a mutant (BP53) that showed a strong CAS reaction independently of the iron levels of the medium. In this mutant the transposon was inserted into the idh gene, which encodes an isocitrate dehydrogenase that participates in the tricarboxylic acid cycle. The mutant did not show any growth impairment in rich or minimal media, but it accumulated a noticeable amount of citrate (around 7 mM) in the culture medium, irrespective of the iron levels. The parental strain accumulated citrate, but in an iron-regulated fashion, being citrate levels 5–6 times higher under iron restricted conditions. In addition, a null mutant deficient in citrate synthase showed an impairment for growth at high concentrations of iron chelators, and showed almost no reaction in the CAS test. Chemical analysis by liquid chromatography of the iron-restricted culture supernatants resulted in a CAS-positive fraction with biological activity as siderophore. HPLC purification of that fraction yielded a pure compound which was identified as citrate from its MS and NMR spectral data. Although the production of another citrate-based compound with siderophore activity cannot be ruled out, our results suggest that Pdd secretes endogenous citrate and use it for iron scavenging from the cell environment.
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Affiliation(s)
- Miguel Balado
- Department of Microbiology and Parasitology, Institute of Aquaculture, University of Santiago de CompostelaSantiago de Compostela, Spain
| | - Beatriz Puentes
- Department of Microbiology and Parasitology, Institute of Aquaculture, University of Santiago de CompostelaSantiago de Compostela, Spain
| | - Lucía Couceiro
- Department of Microbiology and Parasitology, Institute of Aquaculture, University of Santiago de CompostelaSantiago de Compostela, Spain
| | - Juan C Fuentes-Monteverde
- Department of Chemistry, Faculty of Sciences and Center for Advanced Scientific Research (CICA), University of A CoruñaA Coruña, Spain
| | - Jaime Rodríguez
- Department of Chemistry, Faculty of Sciences and Center for Advanced Scientific Research (CICA), University of A CoruñaA Coruña, Spain
| | - Carlos R Osorio
- Department of Microbiology and Parasitology, Institute of Aquaculture, University of Santiago de CompostelaSantiago de Compostela, Spain
| | - Carlos Jiménez
- Department of Chemistry, Faculty of Sciences and Center for Advanced Scientific Research (CICA), University of A CoruñaA Coruña, Spain
| | - Manuel L Lemos
- Department of Microbiology and Parasitology, Institute of Aquaculture, University of Santiago de CompostelaSantiago de Compostela, Spain
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Issa H, Huc-Claustre E, Reddad T, Bonadé Bottino N, Tropis M, Houssin C, Daffé M, Bayan N, Dautin N. Click-chemistry approach to study mycoloylated proteins: Evidence for PorB and PorC porins mycoloylation in Corynebacterium glutamicum. PLoS One 2017; 12:e0171955. [PMID: 28199365 PMCID: PMC5310785 DOI: 10.1371/journal.pone.0171955] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 01/27/2017] [Indexed: 01/23/2023] Open
Abstract
Protein mycoloylation is a recently identified, new form of protein acylation. This post-translational modification consists in the covalent attachment of mycolic acids residues to serine. Mycolic acids are long chain, α-branched, β-hydroxylated fatty acids that are exclusively found in the cell envelope of Corynebacteriales, a bacterial order that includes important genera such as Mycobacterium, Nocardia or Corynebacterium. So far, only 3 mycoloylated proteins have been identified: PorA, PorH and ProtX from C. glutamicum. Whereas the identity and function of ProtX is unknown, PorH and PorA associate to form a membrane channel, the activity of which is dependent upon PorA mycoloylation. However, the exact role of mycoloylation and the generality of this phenomenon are still unknown. In particular, the identity of other mycoloylated proteins, if any, needs to be determined together with establishing whether such modification occurs in Corynebacteriales genera other than Corynebacterium. Here, we tested whether a metabolic labeling and click-chemistry approach could be used to detect mycoloylated proteins. Using a fatty acid alkyne analogue, we could indeed label PorA, PorH and ProtX and determine ProtX mycoloylation site. Importantly, we also show that two other porins from C. glutamicum, PorB and PorC are mycoloylated.
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Affiliation(s)
- Hanane Issa
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
- Holy Spirit University of Kaslik (USEK), Jounieh, Mount Lebanon, Lebanon
| | | | - Thamila Reddad
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Nolwenn Bonadé Bottino
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Maryelle Tropis
- Institute of Pharmacology and Structural Biology (IPBS), UMR 5089, France
| | - Christine Houssin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Mamadou Daffé
- Institute of Pharmacology and Structural Biology (IPBS), UMR 5089, France
| | - Nicolas Bayan
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
| | - Nathalie Dautin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette Cedex, France
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Zhang Y, Cai J, Shang X, Wang B, Liu S, Chai X, Tan T, Zhang Y, Wen T. A new genome-scale metabolic model of Corynebacterium glutamicum and its application. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:169. [PMID: 28680478 PMCID: PMC5493880 DOI: 10.1186/s13068-017-0856-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 06/22/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Corynebacterium glutamicum is an important platform organism for industrial biotechnology to produce amino acids, organic acids, bioplastic monomers, and biofuels. The metabolic flexibility, broad substrate spectrum, and fermentative robustness of C. glutamicum make this organism an ideal cell factory to manufacture desired products. With increases in gene function, transport system, and metabolic profile information under certain conditions, developing a comprehensive genome-scale metabolic model (GEM) of C. glutamicum ATCC13032 is desired to improve prediction accuracy, elucidate cellular metabolism, and guide metabolic engineering. RESULTS Here, we constructed a new GEM for ATCC13032, iCW773, consisting of 773 genes, 950 metabolites, and 1207 reactions. Compared to the previous model, iCW773 supplemented 496 gene-protein-reaction associations, refined five lumped reactions, balanced the mass and charge, and constrained the directionality of reactions. The simulated growth rates of C. glutamicum cultivated on seven different carbon sources using iCW773 were consistent with experimental values. Pearson's correlation coefficient between the iCW773-simulated and experimental fluxes was 0.99, suggesting that iCW773 provided an accurate intracellular flux distribution of the wild-type strain growing on glucose. Furthermore, genetic interventions for overproducing l-lysine, 1,2-propanediol and isobutanol simulated using OptForceMUST were in accordance with reported experimental results, indicating the practicability of iCW773 for the design of metabolic networks to overproduce desired products. In vivo genetic modifications of iCW773-predicted targets resulted in the de novo generation of an l-proline-overproducing strain. In fed-batch culture, the engineered C. glutamicum strain produced 66.43 g/L l-proline in 60 h with a yield of 0.26 g/g (l-proline/glucose) and a productivity of 1.11 g/L/h. To our knowledge, this is the highest titer and productivity reported for l-proline production using glucose as the carbon resource in a minimal medium. CONCLUSIONS Our developed iCW773 serves as a high-quality platform for model-guided strain design to produce industrial bioproducts of interest. This new GEM will be a successful multidisciplinary tool and will make valuable contributions to metabolic engineering in academia and industry.
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Affiliation(s)
- Yu Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Jingyi Cai
- Beijing University of Chemical Technology, Beijing, 100029 China
| | - Xiuling Shang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Bo Wang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Shuwen Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Xin Chai
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Tianwei Tan
- Beijing University of Chemical Technology, Beijing, 100029 China
| | - Yun Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Tingyi Wen
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 100049 China
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Abstract
Virulence gene expression serves two main functions, growth in/on the host, and the acquisition of nutrients. Therefore, it is obvious that nutrient availability is important to control expression of virulence genes. In any cell, enzymes are the components that are best informed about the availability of their respective substrates and products. It is thus not surprising that bacteria have evolved a variety of strategies to employ this information in the control of gene expression. Enzymes that have a second (so-called moonlighting) function in the regulation of gene expression are collectively referred to as trigger enzymes. Trigger enzymes may have a second activity as a direct regulatory protein that can bind specific DNA or RNA targets under particular conditions or they may affect the activity of transcription factors by covalent modification or direct protein-protein interaction. In this chapter, we provide an overview on these mechanisms and discuss the relevance of trigger enzymes for virulence gene expression in bacterial pathogens.
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Otten A, Brocker M, Bott M. Metabolic engineering of Corynebacterium glutamicum for the production of itaconate. Metab Eng 2015; 30:156-165. [DOI: 10.1016/j.ymben.2015.06.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 04/23/2015] [Accepted: 06/11/2015] [Indexed: 10/23/2022]
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Choi JW, Yim SS, Lee SH, Kang TJ, Park SJ, Jeong KJ. Enhanced production of gamma-aminobutyrate (GABA) in recombinant Corynebacterium glutamicum by expressing glutamate decarboxylase active in expanded pH range. Microb Cell Fact 2015; 14:21. [PMID: 25886194 PMCID: PMC4335662 DOI: 10.1186/s12934-015-0205-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 02/05/2015] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Gamma-aminobutylate (GABA) is an important chemical in pharmacetucal field and chemical industry. GABA has mostly been produced in lactic acid bacteria by adding L-glutamate to the culture medium since L-glutamate can be converted into GABA by inherent L-glutamate decarboxylase. Recently, GABA has gained much attention for the application as a major building block for the synthesis of 2-pyrrolidone and biodegradable polyamide nylon 4, which opens its application area in the industrial biotechnology. Therefore, Corynebacterium glutamicum, the major L-glutamate producing microorganism, has been engineered to achieve direct fermentative production of GABA from glucose, but their productivity was rather low. RESULTS Recombinant C. glutamicum strains were developed for enhanced production of GABA from glucose by expressing Escherichia coli glutamate decarboxylase (GAD) mutant, which is active in expanded pH range. Synthetic PH36, PI16, and PL26 promoters, which have different promoter strengths in C. glutamicum, were examined for the expression of E. coli GAD mutant. C. glutamicum expressing E. coli GAD mutant under the strong PH36 promoter could produce GABA to the concentration of 5.89±0.35 g/L in GP1 medium at pH 7.0, which is 17-fold higher than that obtained by C. glutamicum expressing wild-type E. coli GAD in the same condition (0.34±0.26 g/L). Fed-bath culture of C. glutamicum expressing E. coli GAD mutant in GP1 medium containing 50 μg/L of biotin at pH 6, culture condition of which was optimized in flask cultures, resulted in the highest GABA concentration of 38.6±0.85 g/L with the productivity of 0.536 g/L/h. CONCLUSION Recombinant C. glutamicum strains developed in this study should be useful for the direct fermentative production of GABA from glucose, which allows us to achieve enhanced production of GABA suitable for its application area in the industrial biotechnology.
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Affiliation(s)
- Jae Woong Choi
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program), KAIST, 335 Gwahagno, Yuseong-gu, Daejeon, 305-701, Republic of Korea.
| | - Sung Sun Yim
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program), KAIST, 335 Gwahagno, Yuseong-gu, Daejeon, 305-701, Republic of Korea.
| | - Seung Hwan Lee
- Department of Biotechnology and Bioengineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 500-757, Republic of Korea.
| | - Taek Jin Kang
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, 30 Pildong-ro 1-gil, Jung-gu, Seoul, 100-715, Republic of Korea.
| | - Si Jae Park
- Department of Environmental Engineering and Energy, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggido, 449-728, Republic of Korea.
| | - Ki Jun Jeong
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program), KAIST, 335 Gwahagno, Yuseong-gu, Daejeon, 305-701, Republic of Korea.
- Institute for the BioCentury, KAIST, 335 Gwahagno, Yuseong-gu, Daejeon, 305-701, Republic of Korea.
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14
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Septer AN, Bose JL, Lipzen A, Martin J, Whistler C, Stabb EV. Bright luminescence of Vibrio fischeri aconitase mutants reveals a connection between citrate and the Gac/Csr regulatory system. Mol Microbiol 2014; 95:283-96. [PMID: 25402589 DOI: 10.1111/mmi.12864] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2014] [Indexed: 11/28/2022]
Abstract
The Gac/Csr regulatory system is conserved throughout the γ-proteobacteria and controls key pathways in central carbon metabolism, quorum sensing, biofilm formation and virulence in important plant and animal pathogens. Here we show that elevated intracellular citrate levels in a Vibrio fischeri aconitase mutant correlate with activation of the Gac/Csr cascade and induction of bright luminescence. Spontaneous or directed mutations in the gene that encodes citrate synthase reversed the bright luminescence of aconitase mutants, eliminated their citrate accumulation and reversed their elevated expression of CsrB. Our data elucidate a correlative link between central metabolic and regulatory pathways, and they suggest that the Gac system senses a blockage at the aconitase step of the tricarboxylic acid cycle, either through elevated citrate levels or a secondary metabolic effect of citrate accumulation, and responds by modulating carbon flow and various functions associated with host colonization, including bioluminescence.
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Affiliation(s)
- Alecia N Septer
- Department of Microbiology, University of Georgia, 120 Cedar Street, Athens, GA, 30602, USA
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15
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Zahoor A, Otten A, Wendisch VF. Metabolic engineering of Corynebacterium glutamicum for glycolate production. J Biotechnol 2014; 192 Pt B:366-75. [DOI: 10.1016/j.jbiotec.2013.12.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/18/2013] [Accepted: 12/20/2013] [Indexed: 10/25/2022]
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16
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Frawley ER, Fang FC. The ins and outs of bacterial iron metabolism. Mol Microbiol 2014; 93:609-16. [PMID: 25040830 DOI: 10.1111/mmi.12709] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2014] [Indexed: 02/07/2023]
Abstract
Iron is a critical nutrient for the growth and survival of most bacterial species. Accordingly, much attention has been paid to the mechanisms by which host organisms sequester iron from invading bacteria and how bacteria acquire iron from their environment. However, under oxidative stress conditions such as those encountered within phagocytic cells during the host immune response, iron is released from proteins and can act as a catalyst for Fenton chemistry to produce cytotoxic reactive oxygen species. The transitory efflux of free intracellular iron may be beneficial to bacteria under such conditions. The recent discovery of putative iron efflux transporters in Salmonella enterica serovar Typhimurium is discussed in the context of cellular iron homeostasis.
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Affiliation(s)
- Elaine R Frawley
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, USA
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17
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Wynosky-Dolfi MA, Snyder AG, Philip NH, Doonan PJ, Poffenberger MC, Avizonis D, Zwack EE, Riblett AM, Hu B, Strowig T, Flavell RA, Jones RG, Freedman BD, Brodsky IE. Oxidative metabolism enables Salmonella evasion of the NLRP3 inflammasome. ACTA ACUST UNITED AC 2014; 211:653-68. [PMID: 24638169 PMCID: PMC3978275 DOI: 10.1084/jem.20130627] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Salmonella lacking the TCA enzyme aconitase trigger NLRP3 inflammasome activation in infected macrophages, leading to elevated inflammatory responses and reduced virulence. Microbial infection triggers assembly of inflammasome complexes that promote caspase-1–dependent antimicrobial responses. Inflammasome assembly is mediated by members of the nucleotide binding domain leucine-rich repeat (NLR) protein family that respond to cytosolic bacterial products or disruption of cellular processes. Flagellin injected into host cells by invading Salmonella induces inflammasome activation through NLRC4, whereas NLRP3 is required for inflammasome activation in response to multiple stimuli, including microbial infection, tissue damage, and metabolic dysregulation, through mechanisms that remain poorly understood. During systemic infection, Salmonella avoids NLRC4 inflammasome activation by down-regulating flagellin expression. Macrophages exhibit delayed NLRP3 inflammasome activation after Salmonella infection, suggesting that Salmonella may evade or prevent the rapid activation of the NLRP3 inflammasome. We therefore screened a Salmonella Typhimurium transposon library to identify bacterial factors that limit NLRP3 inflammasome activation. Surprisingly, absence of the Salmonella TCA enzyme aconitase induced rapid NLRP3 inflammasome activation. This inflammasome activation correlated with elevated levels of bacterial citrate, and required mitochondrial reactive oxygen species and bacterial citrate synthase. Importantly, Salmonella lacking aconitase displayed NLRP3- and caspase-1/11–dependent attenuation of virulence, and induced elevated serum IL-18 in wild-type mice. Together, our data link Salmonella genes controlling oxidative metabolism to inflammasome activation and suggest that NLRP3 inflammasome evasion promotes systemic Salmonella virulence.
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Affiliation(s)
- Meghan A Wynosky-Dolfi
- Department of Pathobiology, School of Veterinary Medicine; and 2 Immunology Graduate Group and 3 Cell and Molecular Biology Graduate Group, University of Pennsylvania, Kennett Square, PA 19104
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18
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Baumgart M, Unthan S, Rückert C, Sivalingam J, Grünberger A, Kalinowski J, Bott M, Noack S, Frunzke J. Construction of a prophage-free variant of Corynebacterium glutamicum ATCC 13032 for use as a platform strain for basic research and industrial biotechnology. Appl Environ Microbiol 2013; 79:6006-15. [PMID: 23892752 PMCID: PMC3811366 DOI: 10.1128/aem.01634-13] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Accepted: 07/17/2013] [Indexed: 11/20/2022] Open
Abstract
The activity of bacteriophages and phage-related mobile elements is a major source for genome rearrangements and genetic instability of their bacterial hosts. The genome of the industrial amino acid producer Corynebacterium glutamicum ATCC 13032 contains three prophages (CGP1, CGP2, and CGP3) of so far unknown functionality. Several phage genes are regularly expressed, and the large prophage CGP3 (∼190 kbp) has recently been shown to be induced under certain stress conditions. Here, we present the construction of MB001, a prophage-free variant of C. glutamicum ATCC 13032 with a 6% reduced genome. This strain does not show any unfavorable properties during extensive phenotypic characterization under various standard and stress conditions. As expected, we observed improved growth and fitness of MB001 under SOS-response-inducing conditions that trigger CGP3 induction in the wild-type strain. Further studies revealed that MB001 has a significantly increased transformation efficiency and produced about 30% more of the heterologous model protein enhanced yellow fluorescent protein (eYFP), presumably as a consequence of an increased plasmid copy number. These effects were attributed to the loss of the restriction-modification system (cg1996-cg1998) located within CGP3. The deletion of the prophages without any negative effect results in a novel platform strain for metabolic engineering and represents a useful step toward the construction of a C. glutamicum chassis genome of strain ATCC 13032 for biotechnological applications and synthetic biology.
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Affiliation(s)
- Meike Baumgart
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Simon Unthan
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | | | - Jasintha Sivalingam
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Alexander Grünberger
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | | | - Michael Bott
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Stephan Noack
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Julia Frunzke
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
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19
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García-Nafría J, Baumgart M, Turkenburg JP, Wilkinson AJ, Bott M, Wilson KS. Crystal and solution studies reveal that the transcriptional regulator AcnR of Corynebacterium glutamicum is regulated by citrate-Mg2+ binding to a non-canonical pocket. J Biol Chem 2013; 288:15800-12. [PMID: 23589369 PMCID: PMC3668737 DOI: 10.1074/jbc.m113.462440] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 04/11/2013] [Indexed: 11/06/2022] Open
Abstract
Corynebacterium glutamicum is an important industrial bacterium as well as a model organism for the order Corynebacteriales, whose citric acid cycle occupies a central position in energy and precursor supply. Expression of aconitase, which isomerizes citrate into isocitrate, is controlled by several transcriptional regulators, including the dimeric aconitase repressor AcnR, assigned by sequence identity to the TetR family. We report the structures of AcnR in two crystal forms together with ligand binding experiments and in vivo studies. First, there is a citrate-Mg(2+) moiety bound in both forms, not in the canonical TetR ligand binding site but rather in a second pocket more distant from the DNA binding domain. Second, the citrate-Mg(2+) binds with a KD of 6 mM, within the range of physiological significance. Third, citrate-Mg(2+) lowers the affinity of AcnR for its target DNA in vitro. Fourth, analyses of several AcnR point mutations provide evidence for the possible involvement of the corresponding residues in ligand binding, DNA binding, and signal transfer. AcnR derivatives defective in citrate-Mg(2+) binding severely inhibit growth of C. glutamicum on citrate. Finally, the structures do have a pocket corresponding to the canonical tetracycline site, and although we have not identified a ligand that binds there, comparison of the two crystal forms suggests differences in the region of the canonical pocket that may indicate a biological significance.
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Affiliation(s)
- Javier García-Nafría
- From the York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom and
| | - Meike Baumgart
- the Institute of Bio- and Geosciences, IBG-1: Biotechnology, Wilhelm-Johnen-Strasse, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Johan P. Turkenburg
- From the York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom and
| | - Anthony J. Wilkinson
- From the York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom and
| | - Michael Bott
- the Institute of Bio- and Geosciences, IBG-1: Biotechnology, Wilhelm-Johnen-Strasse, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Keith S. Wilson
- From the York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom and
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20
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Two roles for aconitase in the regulation of tricarboxylic acid branch gene expression in Bacillus subtilis. J Bacteriol 2013; 195:1525-37. [PMID: 23354745 DOI: 10.1128/jb.01690-12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previously, it was shown that an aconitase (citB) null mutation results in a vast overaccumulation of citrate in the culture fluid of growing Bacillus subtilis cells, a phenotype that causes secondary effects, including the hyperexpression of the citB promoter. B. subtilis aconitase is a bifunctional protein; to determine if either or both activities of aconitase were responsible for this phenotype, two strains producing different mutant forms of aconitase were constructed, one designed to be enzymatically inactive (C450S [citB2]) and the other designed to be defective in RNA binding (R741E [citB7]). The citB2 mutant was a glutamate auxotroph and accumulated citrate, while the citB7 mutant was a glutamate prototroph. Unexpectedly, the citB7 strain also accumulated citrate. Both mutant strains exhibited overexpression of the citB promoter and accumulated high levels of aconitase protein. These strains and the citB null mutant also exhibited increased levels of citrate synthase protein and enzyme activity in cell extracts, and the major citrate synthase (citZ) transcript was present at higher-than-normal levels in the citB null mutant, due at least in part to a >3-fold increase in the stability of the citZ transcript compared to the wild type. Purified B. subtilis aconitase bound to the citZ 5' leader RNA in vitro, but the mutant proteins did not. Together, these data suggest that wild-type aconitase binds to and destabilizes the citZ transcript in order to maintain proper cell homeostasis by preventing the overaccumulation of citrate.
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21
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Bott M, Eikmanns BJ. TCA Cycle and Glyoxylate Shunt of Corynebacterium glutamicum. CORYNEBACTERIUM GLUTAMICUM 2013. [DOI: 10.1007/978-3-642-29857-8_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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22
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Quantification of proteome dynamics in Corynebacterium glutamicum by (15)N-labeling and selected reaction monitoring. J Proteomics 2012; 75:2660-9. [PMID: 22476105 DOI: 10.1016/j.jprot.2012.03.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 02/22/2012] [Accepted: 03/12/2012] [Indexed: 11/23/2022]
Abstract
Selected reaction monitoring allows quantitative measurements of proteins over several orders of magnitude in complex biological samples. Here we present a targeted approach for quantification of 19 enzymes from Corynebacterium glutamicum applying isotope dilution mass spectrometry coupled to high performance liquid chromatography (IDMS-LC-MS/MS). Investigations of protein dynamics upon growth on acetate and glucose as sole carbon source shows highly stable peptide amounts for enzymes of the central carbon metabolism during the transition phase and after substrate depletion. However significant adaptations of protein amounts are observed between both growth conditions well agreeing with known changes in metabolic fluxes. Time-resolved measurements of protein expression after metabolic switch from glycolytic to gluconeogenetic conditions reveal fast responses in protein synthesis rates for glyoxylate shunt enzymes.
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