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Farahmand S, SamadiAfshar S, Hosseini L. TA-Cloning for Diabetes Treatment: Expressing Corynebacterium Malic Enzyme Gene in E. coli. Curr Microbiol 2024; 81:167. [PMID: 38727744 DOI: 10.1007/s00284-024-03686-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 04/02/2024] [Indexed: 05/16/2024]
Abstract
Diabetes mellitus represents a persistent metabolic condition marked by heightened levels of blood glucose, presenting a considerable worldwide health concern, and finding targeted treatment for it is a crucial priority for global health. Gram-positive aerobic bacteria, predominantly inhabiting water and soil, are known carriers of various enzyme-encoding genetic material, which includes the malic enzyme gene that plays a role in insulin secretion. Corynebacterium glutamicum bacteria (ATCC 21799) were acquired from the Pasteur Institute and confirmed using microbiological and molecular tests, including DNA extraction. After identification, gene purification and cloning of the maeB gene were performed using the TA Cloning method. Additionally, the enhancement of enzyme expression was assessed using the expression vector pET-28a, and validation of simulation results was monitored through a real-time PCR analysis. Based on previous studies, the malic enzyme plays a pivotal role in maintaining glucose homeostasis, and increased expression of this enzyme has been associated with enhanced insulin sensitivity. However, the production of malic enzyme has encountered numerous challenges and difficulties. This study successfully isolated the malic enzyme genes via Corynebacterium glutamicum and introduced them into Escherichia coli for high-yield production. According to the results, the optimum temperature for the activity of enzymes has been identified as 39 °C.
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Affiliation(s)
| | - Saber SamadiAfshar
- Pediatric Health Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ladan Hosseini
- Department of Biology, Payame Noor University (PNU), Tehran, Iran
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2
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Zhao G, Zhao S, Hagner Nielsen L, Zhou F, Gu L, Tilahun Tadesse B, Solem C. Transforming acid whey into a resource by selective removal of lactic acid and galactose using optimized food-grade microorganisms. BIORESOURCE TECHNOLOGY 2023; 387:129594. [PMID: 37532060 DOI: 10.1016/j.biortech.2023.129594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/26/2023] [Accepted: 07/30/2023] [Indexed: 08/04/2023]
Abstract
The presence of lactic acid and galactose makes spray drying of acid whey (AW) a significant challenge for the dairy industry. In this study, a novel approach is explored to remove these compounds, utilizing food-grade microorganisms. For removing lactic acid, Corynebacterium glutamicum was selected, which has an inherent ability to metabolize lactic acid but does so slowly. To accelerate lactic acid metabolism, a mutant strain G6006 was isolated through adaptive laboratory evolution, which metabolized all lactic acid from AW two times faster than its parent strain. To eliminate galactose, a lactose-negative mutant of Lactococcus lactis that cannot produce lactate was generated. This strain was then co-cultured with G6006 to maximize the removal of both lactic acid and galactose. The microbially "filtered" AW could readily be spray dried into a stable lactose powder. This study highlights the potential of utilizing food-grade microorganisms to process AW, which currently constitutes a global challenge.
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Affiliation(s)
- Ge Zhao
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Shuangqing Zhao
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Line Hagner Nielsen
- DTU Health Tech, Department of Health Technology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Fa Zhou
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Liuyan Gu
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Belay Tilahun Tadesse
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Christian Solem
- National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
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3
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Yim SS, Choi JW, Lee YJ, Jeong KJ. Rapid combinatorial rewiring of metabolic networks for enhanced poly(3-hydroxybutyrate) production in Corynebacterium glutamicum. Microb Cell Fact 2023; 22:29. [PMID: 36803485 PMCID: PMC9936768 DOI: 10.1186/s12934-023-02037-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 02/07/2023] [Indexed: 02/19/2023] Open
Abstract
BACKGROUND The disposal of plastic waste is a major environmental challenge. With recent advances in microbial genetic and metabolic engineering technologies, microbial polyhydroxyalkanoates (PHAs) are being used as next-generation biomaterials to replace petroleum-based synthetic plastics in a sustainable future. However, the relatively high production cost of bioprocesses hinders the production and application of microbial PHAs on an industrial scale. RESULTS Here, we describe a rapid strategy to rewire metabolic networks in an industrial microorganism, Corynebacterium glutamicum, for the enhanced production of poly(3-hydroxybutyrate) (PHB). A three-gene PHB biosynthetic pathway in Rasltonia eutropha was refactored for high-level gene expression. A fluorescence-based quantification assay for cellular PHB content using BODIPY was devised for the rapid fluorescence-activated cell sorting (FACS)-based screening of a large combinatorial metabolic network library constructed in C. glutamicum. Rewiring metabolic networks across the central carbon metabolism enabled highly efficient production of PHB up to 29% of dry cell weight with the highest cellular PHB productivity ever reported in C. glutamicum using a sole carbon source. CONCLUSIONS We successfully constructed a heterologous PHB biosynthetic pathway and rapidly optimized metabolic networks across central metabolism in C. glutamicum for enhanced production of PHB using glucose or fructose as a sole carbon source in minimal media. We expect that this FACS-based metabolic rewiring framework will accelerate strain engineering processes for the production of diverse biochemicals and biopolymers.
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Affiliation(s)
- Sung Sun Yim
- grid.37172.300000 0001 2292 0500Department of Biological Sciences, KAIST, Daejeon, Republic of Korea ,grid.37172.300000 0001 2292 0500Institute for BioCentury, KAIST, Daejeon, Republic of Korea
| | - Jae Woong Choi
- grid.418974.70000 0001 0573 0246Traditional Food Research Group, Korea Food Research Institute, Jeonju, Republic of Korea
| | - Yong Jae Lee
- grid.249967.70000 0004 0636 3099Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141 Korea ,grid.412786.e0000 0004 1791 8264Major of Environmental Biotechnology, KRIBB School of Biotechnology, Korea University of Science and Technology (UST), Daejeon, Korea
| | - Ki Jun Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, Daejeon, Republic of Korea. .,Institute for BioCentury, KAIST, Daejeon, Republic of Korea.
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4
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Liu X, Zhao G, Sun S, Fan C, Feng X, Xiong P. Biosynthetic Pathway and Metabolic Engineering of Succinic Acid. Front Bioeng Biotechnol 2022; 10:843887. [PMID: 35350186 PMCID: PMC8957974 DOI: 10.3389/fbioe.2022.843887] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 02/16/2022] [Indexed: 11/25/2022] Open
Abstract
Succinic acid, a dicarboxylic acid produced as an intermediate of the tricarboxylic acid (TCA) cycle, is one of the most important platform chemicals for the production of various high value-added derivatives. As traditional chemical synthesis processes suffer from nonrenewable resources and environment pollution, succinic acid biosynthesis has drawn increasing attention as a viable, more environmentally friendly alternative. To date, several metabolic engineering approaches have been utilized for constructing and optimizing succinic acid cell factories. In this review, different succinic acid biosynthesis pathways are summarized, with a focus on the key enzymes and metabolic engineering approaches, which mainly include redirecting carbon flux, balancing NADH/NAD+ ratios, and optimizing CO2 supplementation. Finally, future perspectives on the microbial production of succinic acid are discussed.
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Affiliation(s)
- Xiutao Liu
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Guang Zhao
- State Key Lab of Microbial Technology, Shandong University, Qingdao, China
| | - Shengjie Sun
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Chuanle Fan
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Xinjun Feng
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Peng Xiong
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
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5
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Harold LK, Jinich A, Hards K, Cordeiro A, Keighley LM, Cross A, McNeil MB, Rhee K, Cook GM. Deciphering functional redundancy and energetics of malate oxidation in mycobacteria. J Biol Chem 2022; 298:101859. [PMID: 35337802 PMCID: PMC9062433 DOI: 10.1016/j.jbc.2022.101859] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 03/20/2022] [Accepted: 03/21/2022] [Indexed: 02/07/2023] Open
Abstract
Oxidation of malate to oxaloacetate, catalyzed by either malate dehydrogenase (Mdh) or malate quinone oxidoreductase (Mqo), is a critical step of the tricarboxylic acid cycle. Both Mqo and Mdh are found in most bacterial genomes, but the level of functional redundancy between these enzymes remains unclear. A bioinformatic survey revealed that Mqo was not as widespread as Mdh in bacteria but that it was highly conserved in mycobacteria. We therefore used mycobacteria as a model genera to study the functional role(s) of Mqo and its redundancy with Mdh. We deleted mqo from the environmental saprophyte Mycobacterium smegmatis, which lacks Mdh, and found that Mqo was essential for growth on nonfermentable carbon sources. On fermentable carbon sources, the Δmqo mutant exhibited delayed growth and lowered oxygen consumption and secreted malate and fumarate as terminal end products. Furthermore, heterologous expression of Mdh from the pathogenic species Mycobacterium tuberculosis shortened the delayed growth on fermentable carbon sources and restored growth on nonfermentable carbon sources at a reduced growth rate. In M. tuberculosis, CRISPR interference of either mdh or mqo expression resulted in a slower growth rate compared to controls, which was further inhibited when both genes were knocked down simultaneously. These data reveal that exergonic Mqo activity powers mycobacterial growth under nonenergy limiting conditions and that endergonic Mdh activity complements Mqo activity, but at an energetic cost for mycobacterial growth. We propose Mdh is maintained in slow-growing mycobacterial pathogens for use under conditions such as hypoxia that require reductive tricarboxylic acid cycle activity.
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Affiliation(s)
- Liam K Harold
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand.
| | - Adrian Jinich
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Kiel Hards
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Alexandra Cordeiro
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Laura M Keighley
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Alec Cross
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Matthew B McNeil
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Kyu Rhee
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Gregory M Cook
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand.
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6
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Zhang H, Ouyang Z, Zhao N, Han S, Zheng S. Transcriptional Regulation of the Creatine Utilization Genes of Corynebacterium glutamicum ATCC 14067 by AmtR, a Central Nitrogen Regulator. Front Bioeng Biotechnol 2022; 10:816628. [PMID: 35223787 PMCID: PMC8864220 DOI: 10.3389/fbioe.2022.816628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/13/2022] [Indexed: 11/23/2022] Open
Abstract
In the genus Corynebacterium, AmtR is a key component of the nitrogen regulatory system, and it belongs to the TetR family of transcription regulators. There has been much research on AmtR structure, functions, and regulons in the type strain C. glutamicum ATCC 13032, but little research in other C. glutamicum strains. In this study, chromatin immunoprecipitation and massively parallel DNA sequencing (ChIP-seq) was performed to identify the AmtR regulon in C. glutamicum ATCC 14067. Ten peaks were obtained in the C. glutamicum ATCC 14067 genome including two new peaks related to three operons (RS_01910-RS_01915, RS_15995, and RS_16000). The interactions between AmtR and the promoter regions of the three operons were confirmed by electrophoretic mobility shift assays (EMSAs). The RS_01910, RS_01915, RS_15995, and RS_16000 are not present in the type strain C. glutamicum ATCC 13032. Sequence analysis indicates that RS_01910, RS_01915, RS_15995, and RS_16000, are related to the degradation of creatine and creatinine; RS_01910 may encode a protein related to creatine transport. The genes RS_01910, RS_01915, RS_15995, and RS_16000 were given the names crnA, creT, cshA, and hyuB, respectively. Real-time quantitative PCR (RT-qPCR) analysis and sfGFP (superfolder green fluorescent protein) analysis reveal that AmtR directly and negatively regulates the transcription and expression of crnA, creT, cshA, and hyuB. A growth test shows that C. glutamicum ATCC 14067 can use creatine or creatinine as a sole nitrogen source. In comparison, a creT deletion mutant strain is able to grow on creatinine but loses the ability to grow on creatine. This study provides the first genome-wide captures of the dynamics of in vivo AmtR binding events and the regulatory network they define. These elements provide more options for synthetic biology by extending the scope of the AmtR regulon.
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Affiliation(s)
- Hao Zhang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Zhilin Ouyang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Nannan Zhao
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Shuangyan Han
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Suiping Zheng
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
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7
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Hoffmann SL, Kohlstedt M, Jungmann L, Hutter M, Poblete-Castro I, Becker J, Wittmann C. Cascaded valorization of brown seaweed to produce l-lysine and value-added products using Corynebacterium glutamicum streamlined by systems metabolic engineering. Metab Eng 2021; 67:293-307. [PMID: 34314893 DOI: 10.1016/j.ymben.2021.07.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 06/23/2021] [Accepted: 07/22/2021] [Indexed: 12/15/2022]
Abstract
Seaweeds emerge as promising third-generation renewable for sustainable bioproduction. In the present work, we valorized brown seaweed to produce l-lysine, the world's leading feed amino acid, using Corynebacterium glutamicum, which was streamlined by systems metabolic engineering. The mutant C. glutamicum SEA-1 served as a starting point for development because it produced small amounts of l-lysine from mannitol, a major seaweed sugar, because of the deletion of its arabitol repressor AtlR and its engineered l-lysine pathway. Starting from SEA-1, we systematically optimized the microbe to redirect excess NADH, formed on the sugar alcohol, towards NADPH, required for l-lysine synthesis. The mannitol dehydrogenase variant MtlD D75A, inspired by 3D protein homology modelling, partly generated NADPH during the oxidation of mannitol to fructose, leading to a 70% increased l-lysine yield in strain SEA-2C. Several rounds of strain engineering further increased NADPH supply and l-lysine production. The best strain, SEA-7, overexpressed the membrane-bound transhydrogenase pntAB together with codon-optimized gapN, encoding NADPH-dependent glyceraldehyde 3-phosphate dehydrogenase, and mak, encoding fructokinase. In a fed-batch process, SEA-7 produced 76 g L-1l-lysine from mannitol at a yield of 0.26 mol mol-1 and a maximum productivity of 2.1 g L-1 h-1. Finally, SEA-7 was integrated into seaweed valorization cascades. Aqua-cultured Laminaria digitata, a major seaweed for commercial alginate, was extracted and hydrolyzed enzymatically, followed by recovery and clean-up of pure alginate gum. The residual sugar-based mixture was converted to l-lysine at a yield of 0.27 C-mol C-mol-1 using SEA-7. Second, stems of the wild-harvested seaweed Durvillaea antarctica, obtained as waste during commercial processing of the blades for human consumption, were extracted using acid treatment. Fermentation of the hydrolysate using SEA-7 provided l-lysine at a yield of 0.40 C-mol C-mol-1. Our findings enable improvement of the efficiency of seaweed biorefineries using tailor-made C. glutamicum strains.
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Affiliation(s)
- Sarah Lisa Hoffmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Michael Kohlstedt
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Lukas Jungmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Michael Hutter
- Centre for Bioinformatics, Saarland University, Saarbrücken, Germany
| | | | - Judith Becker
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
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8
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Organic Acid Profiles of Phosphate Solubilizing Bacterial Strains in the Presence of Different Insoluble Phosphatic Sources Under In vitro Buffered Conditions. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2021. [DOI: 10.22207/jpam.15.2.59] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The production of weak organic acids by microorganisms has been attributed as the prime reason for the solubilization of insoluble phosphates under both in vitro and soil conditions. Literature seems to be heavily biased towards gluconic acid production by microbes and its subsequent release into the environment as the key factor responsible for phosphate solubilization. This has found credibility since gluconic acid being a product of the Kreb’s cycle is often detected in large quantities in the culture media, when assayed under in vitro conditions. In the present work, the organic acid profiles of four elite phosphate solubilising isolates were determined in the presence of different insoluble sources of phosphates, under in vitro buffered culture conditions by HPLC (High-Performance Liquid Chromatography). While most previous studies did not use a buffered culture media for elucidating the organic acid profile of phosphate solubilizing bacterial isolates, we used a buffered media for estimation of the organic acid profiles. The results revealed that apart from gluconic acid, malic acid is produced in significant levels by phosphate solubilizing bacterial isolates, and there seems to be a differential pattern of production of these two organic acids by the isolates in the presence of different insoluble phosphate sources.
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9
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Harding CJ, Cadby IT, Moynihan PJ, Lovering AL. A rotary mechanism for allostery in bacterial hybrid malic enzymes. Nat Commun 2021; 12:1228. [PMID: 33623032 PMCID: PMC7902834 DOI: 10.1038/s41467-021-21528-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 02/01/2021] [Indexed: 01/31/2023] Open
Abstract
Bacterial hybrid malic enzymes (MaeB grouping, multidomain) catalyse the transformation of malate to pyruvate, and are a major contributor to cellular reducing power and carbon flux. Distinct from other malic enzyme subtypes, the hybrid enzymes are regulated by acetyl-CoA, a molecular indicator of the metabolic state of the cell. Here we solve the structure of a MaeB protein, which reveals hybrid enzymes use the appended phosphotransacetylase (PTA) domain to form a hexameric sensor that communicates acetyl-CoA occupancy to the malic enzyme active site, 60 Å away. We demonstrate that allostery is governed by a large-scale rearrangement that rotates the catalytic subunits 70° between the two states, identifying MaeB as a new model enzyme for the study of ligand-induced conformational change. Our work provides the mechanistic basis for metabolic control of hybrid malic enzymes, and identifies inhibition-insensitive variants that may find utility in synthetic biology.
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Affiliation(s)
- Christopher John Harding
- grid.6572.60000 0004 1936 7486Department of Biosciences, University of Birmingham, Birmingham, UK
| | - Ian Thomas Cadby
- grid.6572.60000 0004 1936 7486Department of Biosciences, University of Birmingham, Birmingham, UK
| | - Patrick Joseph Moynihan
- grid.6572.60000 0004 1936 7486Department of Biosciences, University of Birmingham, Birmingham, UK
| | - Andrew Lee Lovering
- grid.6572.60000 0004 1936 7486Department of Biosciences, University of Birmingham, Birmingham, UK
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10
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Kappelmann J, Klein B, Papenfuß M, Lange J, Blombach B, Takors R, Wiechert W, Polen T, Noack S. Comprehensive Analysis of C. glutamicum Anaplerotic Deletion Mutants Under Defined d-Glucose Conditions. Front Bioeng Biotechnol 2021; 8:602936. [PMID: 33553115 PMCID: PMC7855459 DOI: 10.3389/fbioe.2020.602936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 12/17/2020] [Indexed: 01/07/2023] Open
Abstract
Wild-type C. glutamicum ATCC 13032 is known to possess two enzymes with anaplerotic (C4-directed) carboxylation activity, namely phosphoenolpyruvate carboxylase (PEPCx) and pyruvate carboxylase (PCx). On the other hand, C3-directed decarboxylation can be catalyzed by the three enzymes phosphoenolpyruvate carboxykinase (PEPCk), oxaloacetate decarboxylase (ODx), and malic enzyme (ME). The resulting high metabolic flexibility at the anaplerotic node compromises the unambigous determination of its carbon and energy flux in C. glutamicum wild type. To circumvent this problem we performed a comprehensive analysis of selected single or double deletion mutants in the anaplerosis of wild-type C. glutamicum under defined d-glucose conditions. By applying well-controlled lab-scale bioreactor experiments in combination with untargeted proteomics, quantitative metabolomics and whole-genome sequencing hitherto unknown, and sometimes counter-intuitive, genotype-phenotype relationships in these mutants could be unraveled. In comparison to the wild type the four mutants C. glutamiucm Δpyc, C. glutamiucm Δpyc Δodx, C. glutamiucm Δppc Δpyc, and C. glutamiucm Δpck showed lowered specific growth rates and d-glucose uptake rates, underlining the importance of PCx and PEPCk activity for a balanced carbon and energy flux at the anaplerotic node. Most interestingly, the strain C. glutamiucm Δppc Δpyc could be evolved to grow on d-glucose as the only source of carbon and energy, whereas this combination was previously considered lethal. The prevented anaplerotic carboxylation activity of PEPCx and PCx was found in the evolved strain to be compensated by an up-regulation of the glyoxylate shunt, potentially in combination with the 2-methylcitrate cycle.
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Affiliation(s)
- Jannick Kappelmann
- Institute of Bio- and Geosciences 1, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Bianca Klein
- Institute of Bio- and Geosciences 1, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Mathias Papenfuß
- Institute of Biochemical Engineering, Braunschweig University of Technology, Braunschweig, Germany
| | - Julian Lange
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Bastian Blombach
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Straubing, Germany
| | - Ralf Takors
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Wolfgang Wiechert
- Institute of Bio- and Geosciences 1, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Tino Polen
- Institute of Bio- and Geosciences 1, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Stephan Noack
- Institute of Bio- and Geosciences 1, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
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11
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Ryabchenko LE, Leonova TE, Shustikova TE, Gerasimova TV, Ivankova TA, Sidorenko KV, Yanenko AS. Expression of the NADPH+-Dependent Formate-Dehydrogenase Gene from Pseudomonas Increases Lysine Production in Corynebacterium glutamicum. APPL BIOCHEM MICRO+ 2020. [DOI: 10.1134/s0003683820080086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Llamas-Ramírez R, Takahashi-Iñiguez T, Flores ME. The phosphoenolpyruvate-pyruvate-oxaloacetate node genes and enzymes in Streptomyces coelicolor M-145. Int Microbiol 2020; 23:429-439. [PMID: 31900743 DOI: 10.1007/s10123-019-00116-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/11/2019] [Accepted: 12/15/2019] [Indexed: 01/19/2023]
Abstract
The phosphoenolpyruvate-pyruvate-oxaloacetate node is a major branch within the central carbon metabolism and acts as a connection point between glycolysis, gluconeogenesis, and the TCA cycle. Phosphoenolpyruvate carboxylase, pyruvate carboxylase, phosphoenolpyruvate carboxykinase, malic enzymes, and pyruvate kinase, among others, are enzymes included in this node. We determined the mRNA levels and specific activity profiles of some of these genes and enzymes in Streptomyces coelicolor M-145. The results obtained in the presence of glucose demonstrated that all genes studied of the phosphoenolpyruvate-pyruvate-oxaloacetate node were expressed, although at different levels, with 10- to 100-fold differences. SCO3127 (phosphoenolpyruvate carboxylase gene) and SCO5261 (NADP+-dependent malic enzyme gene) showed the highest expression in the rapid growth phase, and the mRNA levels corresponding to SCO5896 (phosphoenolpyruvate-utilizing enzyme gene), and SCO0546 (pyruvate carboxylase gene) increased 5- to 10-fold towards the stationary phase. In casamino acids, in general mRNA levels of S. coelicolor were lower than in glucose, however, results showed greater mRNA expression of SCO4979 (PEP carboxykinase), SCO0208 (pyruvate phosphate dikinase gene), and SCO5261 (NADP+-dependent malic enzyme). These results suggest that PEP carboxylase (SCO3127) is an important enzyme during glucose catabolism and oxaloacetate replenishment. On the other hand, phosphoenolpyruvate carboxykinase, pyruvate phosphate dikinase, and NADP+-malic enzyme could have an important role in gluconeogenesis in S. coelicolor.
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Affiliation(s)
- Reneé Llamas-Ramírez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico.,Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
| | - Toshiko Takahashi-Iñiguez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
| | - María Elena Flores
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico.
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13
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Role of the malic enzyme in metabolism of the halotolerant methanotroph Methylotuvimicrobium alcaliphilum 20Z. PLoS One 2019; 14:e0225054. [PMID: 31738793 PMCID: PMC6860931 DOI: 10.1371/journal.pone.0225054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 10/28/2019] [Indexed: 01/10/2023] Open
Abstract
The bacteria utilizing methane as a growth substrate (methanotrophs) are important constituents of the biosphere. Methanotrophs mitigate the emission of anthropogenic and natural greenhouse gas methane to the environment and are the promising agents for future biotechnologies. Many aspects of CH4 bioconversion by methanotrophs require further clarification. This study was aimed at characterizing the biochemical properties of the malic enzyme (Mae) from the halotolerant obligate methanotroph Methylotuvimicrobium alcaliphilum 20Z. The His6-tagged Mae was obtained by heterologous expression in Escherichia coli BL21 (DE3) and purified by affinity metal chelating chromatography. As determined by gel filtration and non-denaturating gradient gel electrophoresis, the molecular mass of the native enzyme is 260 kDa. The homotetrameric Mae (65x4 kDa) catalyzed an irreversible NAD+-dependent reaction of L-malate decarboxylation into pyruvate with a specific activity of 32 ± 2 units mg-1 and Km value of 5.5 ± 0.8 mM for malate and 57 ± 5 μM for NAD+. The disruption of the mae gene by insertion mutagenesis resulted in a 20-fold increase in intracellular malate level in the mutant compared to the wild type strain. Based on both enzyme and mutant properties, we conclude that the malic enzyme is involved in the control of intracellular L-malate level in Mtm. alcaliphilum 20Z. Genomic analysis has revealed that Maes present in methanotrophs fall into two different clades in the amino acid-based phylogenetic tree, but no correlation of the division with taxonomic affiliations of the host bacteria was observed.
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14
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Rozova ON, Khmelenina VN, Mustakhimov II, But SY, Trotsenko YA. Properties of Malic Enzyme from the Aerobic Methanotroph Methylosinus trichosporium. BIOCHEMISTRY (MOSCOW) 2019; 84:390-397. [PMID: 31228930 DOI: 10.1134/s0006297919040060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recombinant malic enzyme from the aerobic methanotroph Methylosinus trichosporium was obtained by heterologous expression in Escherichia coli and purified by affinity metal-chelating chromatography. The homohexameric enzyme of 6×80 kDa catalyzed the reversible reaction of oxidative decarboxylation of malate to pyruvate in the presence of mono- and divalent cations and NADP+ as a cofactor. The kcat/Km ratio indicated much higher catalytic efficiency of the malate decarboxylation reaction as compared with the pyruvate carboxylation reaction. Analysis of the protein sequence revealed that the C-region of the enzyme contains a large domain homologous to phosphoacetyltransferase, but no phosphoacetyltransferase activity was detected either for a full chimeric malic enzyme or for the C-end fragment obtained as a separate protein. This C-end domain promoted activity of the malic enzyme.
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Affiliation(s)
- O N Rozova
- G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow Region, 142290, Russia
| | - V N Khmelenina
- G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow Region, 142290, Russia.
| | - I I Mustakhimov
- G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow Region, 142290, Russia
| | - S Y But
- G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow Region, 142290, Russia
| | - Yu A Trotsenko
- G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow Region, 142290, Russia
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15
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Hünnefeld M, Persicke M, Kalinowski J, Frunzke J. The MarR-Type Regulator MalR Is Involved in Stress-Responsive Cell Envelope Remodeling in Corynebacterium glutamicum. Front Microbiol 2019; 10:1039. [PMID: 31164873 PMCID: PMC6536590 DOI: 10.3389/fmicb.2019.01039] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/25/2019] [Indexed: 12/03/2022] Open
Abstract
It is the enormous adaptive capacity of microorganisms, which is key to their competitive success in nature, but also challenges antibiotic treatment of human diseases. To deal with a diverse set of stresses, bacteria are able to reprogram gene expression using a wide variety of transcription factors. Here, we focused on the MarR-type regulator MalR conserved in the Corynebacterineae, including the prominent pathogens Corynebacterium diphtheriae and Mycobacterium tuberculosis. In several corynebacterial species, the malR gene forms an operon with a gene encoding a universal stress protein (uspA). Chromatin affinity purification and sequencing (ChAP-Seq) analysis revealed that MalR binds more than 60 target promoters in the C. glutamicum genome as well as in the large cryptic prophage CGP3. Overproduction of MalR caused severe growth defects and an elongated cell morphology. ChAP-Seq data combined with a global transcriptome analysis of the malR overexpression strain emphasized a central role of MalR in cell envelope remodeling in response to environmental stresses. For example, prominent MalR targets are involved in peptidoglycan biosynthesis and synthesis of branched-chain fatty acids. Phenotypic microarrays suggested an altered sensitivity of a ΔmalR mutant toward several β-lactam antibiotics. Furthermore, we revealed MalR as a repressor of several prophage genes, suggesting that MalR may be involved in the control of stress-responsive induction of the large CGP3 element. In conclusion, our results emphasize MalR as a regulator involved in stress-responsive remodeling of the cell envelope of C. glutamicum and suggest a link between cell envelope stress and the control of phage gene expression.
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Affiliation(s)
- Max Hünnefeld
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Marcus Persicke
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Julia Frunzke
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
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16
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Hernández MA, Alvarez HM. Increasing lipid production using an NADP +-dependent malic enzyme from Rhodococcus jostii. MICROBIOLOGY-SGM 2018; 165:4-14. [PMID: 30372408 DOI: 10.1099/mic.0.000736] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The occurrence of NADP+-dependent malic enzymes (NADP+-MEs) in several Rhodococcus strains was analysed. The NADP+-ME number in Rhodococcus genomes seemed to be a strain-dependent property. Total NADP+-ME activity increased by 1.8- and 2.6-fold in the oleaginous Rhodococcus jostii RHA1 and Rhodococcus opacus PD630 strains during cultivation under nitrogen-limiting conditions. Total NADP+-ME activity inhibition by sesamol resulted in a significant decrease of the cellular biomass and lipid production in oleaginous rhodococci. A non-redundant ME coded by the RHA1_RS44255 gene located in a megaplasmid (pRHL3) of R. jostii RHA1 was characterized and its heterologous expression in Escherichia coli resulted in a twofold increase in ME activity in an NADP+-dependent manner. The overexpression of RHA1_RS44255 in RHA1 and PD630 strains grown on glucose promoted an increase in total NADP+-ME activity and an up to 1.9-foldincrease in total fatty acid production without sacrificing cellular biomass. On the other hand, its expression in Rhodococcus fascians F7 grown on glycerol resulted in a 1.3-1.4-foldincrease in total fatty acid content. The results of this study confirmed the contribution of NADP+-MEs to TAG accumulation in oleaginous rhodococci and the utility of these enzymes as an alternative approach to increase bacterial oil production from different carbon sources.
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Affiliation(s)
- Martín A Hernández
- Facultad de Ciencias Naturales, Instituto de Biociencias de la Patagonia, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de la Patagonia San Juan Bosco, Ruta Provincial no. 1, Km 4-Ciudad Universitaria, 9000 Comodoro Rivadavia, Chubut, Argentina
| | - Héctor M Alvarez
- Facultad de Ciencias Naturales, Instituto de Biociencias de la Patagonia, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de la Patagonia San Juan Bosco, Ruta Provincial no. 1, Km 4-Ciudad Universitaria, 9000 Comodoro Rivadavia, Chubut, Argentina
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17
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Lange A, Becker J, Schulze D, Cahoreau E, Portais JC, Haefner S, Schröder H, Krawczyk J, Zelder O, Wittmann C. Bio-based succinate from sucrose: High-resolution 13C metabolic flux analysis and metabolic engineering of the rumen bacterium Basfia succiniciproducens. Metab Eng 2017; 44:198-212. [PMID: 29037780 DOI: 10.1016/j.ymben.2017.10.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 09/10/2017] [Accepted: 10/04/2017] [Indexed: 01/12/2023]
Abstract
Succinic acid is a platform chemical of recognized industrial value and accordingly faces a continuous challenge to enable manufacturing from most attractive raw materials. It is mainly produced from glucose, using microbial fermentation. Here, we explore and optimize succinate production from sucrose, a globally applied substrate in biotechnology, using the rumen bacterium Basfia succiniciproducens DD1. As basis of the strain optimization, the yet unknown sucrose metabolism of the microbe was studied, using 13C metabolic flux analyses. When grown in batch culture on sucrose, the bacterium exhibited a high succinate yield of 1molmol-1 and a by-product spectrum, which did not match the expected PTS-mediated sucrose catabolism. This led to the discovery of a fructokinase, involved in sucrose catabolism. The flux approach unraveled that the fructokinase and the fructose PTS both contribute to phosphorylation of the fructose part of sucrose. The contribution of the fructokinase reduces the undesired loss of the succinate precursor PEP into pyruvate and into pyruvate-derived by-products and enables increased succinate production, exclusively via the reductive TCA cycle branch. These findings were used to design superior producers. Mutants, which (i) overexpress the beneficial fructokinase, (II) lack the competing fructose PTS, and (iii) combine both traits, produce significantly more succinate. In a fed-batch process, B. succiniciproducens ΔfruA achieved a titer of 71gL-1 succinate and a yield of 2.5molmol-1 from sucrose.
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Affiliation(s)
- Anna Lange
- Institute of Systems Biotechnology, Saarland University, Germany
| | - Judith Becker
- Institute of Systems Biotechnology, Saarland University, Germany
| | - Dennis Schulze
- Institute of Systems Biotechnology, Saarland University, Germany
| | - Edern Cahoreau
- Université de Toulouse, INSA, UPS, INP, Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France
| | - Jean-Charles Portais
- Université de Toulouse, INSA, UPS, INP, Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France
| | - Stefan Haefner
- BASF SE, Fine Chemicals and Biotechnology, Ludwigshafen, Germany
| | - Hartwig Schröder
- BASF SE, Fine Chemicals and Biotechnology, Ludwigshafen, Germany
| | - Joanna Krawczyk
- BASF SE, Fine Chemicals and Biotechnology, Ludwigshafen, Germany
| | - Oskar Zelder
- BASF SE, Fine Chemicals and Biotechnology, Ludwigshafen, Germany
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18
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Kappelmann J, Wiechert W, Noack S. Cutting the Gordian Knot: Identifiability of anaplerotic reactions in Corynebacterium glutamicum by means of (13) C-metabolic flux analysis. Biotechnol Bioeng 2015; 113:661-74. [PMID: 26375179 DOI: 10.1002/bit.25833] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/04/2015] [Accepted: 09/09/2015] [Indexed: 12/20/2022]
Abstract
Corynebacterium glutamicum is the major workhorse for the microbial production of several amino and organic acids. As long as these derive from tricarboxylic acid cycle intermediates, the activity of anaplerotic reactions is pivotal for a high biosynthetic yield. To determine single anaplerotic activities (13) C-Metabolic Flux Analysis ((13) C-MFA) has been extensively used for C. glutamicum, however with different network topologies, inconsistent or poorly determined anaplerotic reaction rates. Therefore, in this study we set out to investigate whether a focused isotopomer model of the anaplerotic node can at all admit a unique solution for all fluxes. By analyzing different scenarios of active anaplerotic reactions, we show in full generality that for C. glutamicum only certain anaplerotic deletion mutants allow to uniquely determine the anaplerotic fluxes from (13) C-isotopomer data. We stress that the result of this analysis for different assumptions on active enzymes is directly transferable to other compartment-free organisms. Our results demonstrate that there exist biologically relevant metabolic network topologies for which the flux distribution cannot be inferred by classical (13) C-MFA.
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Affiliation(s)
- Jannick Kappelmann
- Institute of Bio- and Geosciences, IBG-1:Biotechnology, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Wolfgang Wiechert
- Institute of Bio- and Geosciences, IBG-1:Biotechnology, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Stephan Noack
- Institute of Bio- and Geosciences, IBG-1:Biotechnology, Forschungszentrum Jülich, D-52425, Jülich, Germany.
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19
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Anaerobic growth of Corynebacterium glutamicum via mixed-acid fermentation. Appl Environ Microbiol 2015; 81:7496-508. [PMID: 26276118 DOI: 10.1128/aem.02413-15] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 08/11/2015] [Indexed: 01/01/2023] Open
Abstract
Corynebacterium glutamicum, a model organism in microbial biotechnology, is known to metabolize glucose under oxygen-deprived conditions to l-lactate, succinate, and acetate without significant growth. This property is exploited for efficient production of lactate and succinate. Our detailed analysis revealed that marginal growth takes place under anaerobic conditions with glucose, fructose, sucrose, or ribose as a carbon and energy source but not with gluconate, pyruvate, lactate, propionate, or acetate. Supplementation of glucose minimal medium with tryptone strongly enhanced growth up to a final optical density at 600 nm (OD600) of 12, whereas tryptone alone did not allow growth. Amino acids with a high ATP demand for biosynthesis and amino acids of the glutamate family were particularly important for growth stimulation, indicating ATP limitation and a restricted carbon flux into the oxidative tricarboxylic acid cycle toward 2-oxoglutarate. Anaerobic cultivation in a bioreactor with constant nitrogen flushing disclosed that CO2 is required to achieve maximal growth and that the pH tolerance is reduced compared to that under aerobic conditions, reflecting a decreased capability for pH homeostasis. Continued growth under anaerobic conditions indicated the absence of an oxygen-requiring reaction that is essential for biomass formation. The results provide an improved understanding of the physiology of C. glutamicum under anaerobic conditions.
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20
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Spaans SK, Weusthuis RA, van der Oost J, Kengen SWM. NADPH-generating systems in bacteria and archaea. Front Microbiol 2015; 6:742. [PMID: 26284036 PMCID: PMC4518329 DOI: 10.3389/fmicb.2015.00742] [Citation(s) in RCA: 197] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 07/06/2015] [Indexed: 12/22/2022] Open
Abstract
Reduced nicotinamide adenine dinucleotide phosphate (NADPH) is an essential electron donor in all organisms. It provides the reducing power that drives numerous anabolic reactions, including those responsible for the biosynthesis of all major cell components and many products in biotechnology. The efficient synthesis of many of these products, however, is limited by the rate of NADPH regeneration. Hence, a thorough understanding of the reactions involved in the generation of NADPH is required to increase its turnover through rational strain improvement. Traditionally, the main engineering targets for increasing NADPH availability have included the dehydrogenase reactions of the oxidative pentose phosphate pathway and the isocitrate dehydrogenase step of the tricarboxylic acid (TCA) cycle. However, the importance of alternative NADPH-generating reactions has recently become evident. In the current review, the major canonical and non-canonical reactions involved in the production and regeneration of NADPH in prokaryotes are described, and their key enzymes are discussed. In addition, an overview of how different enzymes have been applied to increase NADPH availability and thereby enhance productivity is provided.
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Affiliation(s)
| | - Ruud A. Weusthuis
- Bioprocess Engineering, Wageningen UniversityWageningen, Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands
| | - Servé W. M. Kengen
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands
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21
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Reassessment of the transhydrogenase/malate shunt pathway in Clostridium thermocellum ATCC 27405 through kinetic characterization of malic enzyme and malate dehydrogenase. Appl Environ Microbiol 2015; 81:2423-32. [PMID: 25616802 DOI: 10.1128/aem.03360-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Clostridium thermocellum produces ethanol as one of its major end products from direct fermentation of cellulosic biomass. Therefore, it is viewed as an attractive model for the production of biofuels via consolidated bioprocessing. However, a better understanding of the metabolic pathways, along with their putative regulation, could lead to improved strategies for increasing the production of ethanol. In the absence of an annotated pyruvate kinase in the genome, alternate means of generating pyruvate have been sought. Previous proteomic and transcriptomic work detected high levels of a malate dehydrogenase and malic enzyme, which may be used as part of a malate shunt for the generation of pyruvate from phosphoenolpyruvate. The purification and characterization of the malate dehydrogenase and malic enzyme are described in order to elucidate their putative roles in malate shunt and their potential role in C. thermocellum metabolism. The malate dehydrogenase catalyzed the reduction of oxaloacetate to malate utilizing NADH or NADPH with a kcat of 45.8 s(-1) or 14.9 s(-1), respectively, resulting in a 12-fold increase in catalytic efficiency when using NADH over NADPH. The malic enzyme displayed reversible malate decarboxylation activity with a kcat of 520.8 s(-1). The malic enzyme used NADP(+) as a cofactor along with NH4 (+) and Mn(2+) as activators. Pyrophosphate was found to be a potent inhibitor of malic enzyme activity, with a Ki of 0.036 mM. We propose a putative regulatory mechanism of the malate shunt by pyrophosphate and NH4 (+) based on the characterization of the malate dehydrogenase and malic enzyme.
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22
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Liang YJ, Jiang JG. Characterization of malic enzyme and the regulation of its activity and metabolic engineering on lipid production. RSC Adv 2015. [DOI: 10.1039/c5ra04635a] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Nowadays, microbial lipids are employed as the feedstock for biodiesel production, which has attracted great attention across the whole world.
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Affiliation(s)
- Ying-Jie Liang
- School of Biological Science & Engineering
- South China University of Technology
- Guangzhou
- China
| | - Jian-Guo Jiang
- School of Biological Science & Engineering
- South China University of Technology
- Guangzhou
- China
- College of Food Science and Engineering
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23
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Adler P, Frey LJ, Berger A, Bolten CJ, Hansen CE, Wittmann C. The key to acetate: metabolic fluxes of acetic acid bacteria under cocoa pulp fermentation-simulating conditions. Appl Environ Microbiol 2014; 80:4702-16. [PMID: 24837393 PMCID: PMC4148806 DOI: 10.1128/aem.01048-14] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 05/14/2014] [Indexed: 11/20/2022] Open
Abstract
Acetic acid bacteria (AAB) play an important role during cocoa fermentation, as their main product, acetate, is a major driver for the development of the desired cocoa flavors. Here, we investigated the specialized metabolism of these bacteria under cocoa pulp fermentation-simulating conditions. A carefully designed combination of parallel 13C isotope labeling experiments allowed the elucidation of intracellular fluxes in the complex environment of cocoa pulp, when lactate and ethanol were included as primary substrates among undefined ingredients. We demonstrate that AAB exhibit a functionally separated metabolism during coconsumption of two-carbon and three-carbon substrates. Acetate is almost exclusively derived from ethanol, while lactate serves for the formation of acetoin and biomass building blocks. Although this is suboptimal for cellular energetics, this allows maximized growth and conversion rates. The functional separation results from a lack of phosphoenolpyruvate carboxykinase and malic enzymes, typically present in bacteria to interconnect metabolism. In fact, gluconeogenesis is driven by pyruvate phosphate dikinase. Consequently, a balanced ratio of lactate and ethanol is important for the optimum performance of AAB. As lactate and ethanol are individually supplied by lactic acid bacteria and yeasts during the initial phase of cocoa fermentation, respectively, this underlines the importance of a well-balanced microbial consortium for a successful fermentation process. Indeed, AAB performed the best and produced the largest amounts of acetate in mixed culture experiments when lactic acid bacteria and yeasts were both present.
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Affiliation(s)
- Philipp Adler
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
| | - Lasse Jannis Frey
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
| | - Antje Berger
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
| | | | - Carl Erik Hansen
- Nestlé Research Center, Vers-Chez-Les-Blanc, Lausanne, Switzerland
| | - Christoph Wittmann
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
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24
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Genome-wide analysis of the role of global transcriptional regulator GntR1 in Corynebacterium glutamicum. J Bacteriol 2014; 196:3249-58. [PMID: 24982307 DOI: 10.1128/jb.01860-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The transcriptional regulator GntR1 downregulates the genes for gluconate catabolism and pentose phosphate pathway in Corynebacterium glutamicum. Gluconate lowers the DNA binding affinity of GntR1, which is probably the mechanism of gluconate-dependent induction of these genes. In addition, GntR1 positively regulates ptsG, a gene encoding a major glucose transporter, and pck, a gene encoding phosphoenolpyruvate carboxykinase. Here, we searched for the new target of GntR1 on a genome-wide scale by chromatin immunoprecipitation in conjunction with microarray (ChIP-chip) analysis. This analysis identified 56 in vivo GntR1 binding sites, of which 7 sites were previously reported. The newly identified GntR1 sites include the upstream regions of carbon metabolism genes such as pyk, maeB, gapB, and icd, encoding pyruvate kinase, malic enzyme, glyceraldehyde 3-phosphate dehydrogenase B, and isocitrate dehydrogenase, respectively. Binding of GntR1 to the promoter region of these genes was confirmed by electrophoretic mobility shift assay. The activity of the icd, gapB, and maeB promoters was reduced by the mutation at the GntR1 binding site, in contrast to the pyk promoter activity, which was increased, indicating that GntR1 is a transcriptional activator of icd, gapB, and maeB and is a repressor of pyk. Thus, it is likely that GntR1 stimulates glucose uptake by inducing the phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS) gene while repressing pyk to increase PEP availability in the absence of gluconate. Repression of zwf and gnd may reduce the NADPH supply, which may be compensated by the induction of maeB and icd. Upregulation of icd, gapB, and maeB and downregulation of pyk by GntR1 probably support gluconeogenesis.
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25
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Carbon flux analysis by 13C nuclear magnetic resonance to determine the effect of CO2 on anaerobic succinate production by Corynebacterium glutamicum. Appl Environ Microbiol 2014; 80:3015-24. [PMID: 24610842 DOI: 10.1128/aem.04189-13] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Wild-type Corynebacterium glutamicum produces a mixture of lactic, succinic, and acetic acids from glucose under oxygen deprivation. We investigated the effect of CO2 on the production of organic acids in a two-stage process: cells were grown aerobically in glucose, and subsequently, organic acid production by nongrowing cells was studied under anaerobic conditions. The presence of CO2 caused up to a 3-fold increase in the succinate yield (1 mol per mol of glucose) and about 2-fold increase in acetate, both at the expense of l-lactate production; moreover, dihydroxyacetone formation was abolished. The redistribution of carbon fluxes in response to CO2 was estimated by using (13)C-labeled glucose and (13)C nuclear magnetic resonance (NMR) analysis of the labeling patterns in end products. The flux analysis showed that 97% of succinate was produced via the reductive part of the tricarboxylic acid cycle, with the low activity of the oxidative branch being sufficient to provide the reducing equivalents needed for the redox balance. The flux via the pentose phosphate pathway was low (~5%) regardless of the presence or absence of CO2. Moreover, there was significant channeling of carbon to storage compounds (glycogen and trehalose) and concomitant catabolism of these reserves. The intracellular and extracellular pools of lactate and succinate were measured by in vivo NMR, and the stoichiometry (H(+):organic acid) of the respective exporters was calculated. This study shows that it is feasible to take advantage of natural cellular regulation mechanisms to obtain high yields of succinate with C. glutamicum without genetic manipulation.
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Blombach B, Buchholz J, Busche T, Kalinowski J, Takors R. Impact of different CO2/HCO3− levels on metabolism and regulation in Corynebacterium glutamicum. J Biotechnol 2013; 168:331-40. [DOI: 10.1016/j.jbiotec.2013.10.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 09/30/2013] [Accepted: 10/04/2013] [Indexed: 01/26/2023]
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Phosphotransferase system-mediated glucose uptake is repressed in phosphoglucoisomerase-deficient Corynebacterium glutamicum strains. Appl Environ Microbiol 2013; 79:2588-95. [PMID: 23396334 DOI: 10.1128/aem.03231-12] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Corynebacterium glutamicum is particularly known for its industrial application in the production of amino acids. Amino acid overproduction comes along with a high NADPH demand, which is covered mainly by the oxidative part of the pentose phosphate pathway (PPP). In previous studies, the complete redirection of the carbon flux toward the PPP by chromosomal inactivation of the pgi gene, encoding the phosphoglucoisomerase, has been applied for the improvement of C. glutamicum amino acid production strains, but this was accompanied by severe negative effects on the growth characteristics. To investigate these effects in a genetically defined background, we deleted the pgi gene in the type strain C. glutamicum ATCC 13032. The resulting strain, C. glutamicum Δpgi, lacked detectable phosphoglucoisomerase activity and grew poorly with glucose as the sole substrate. Apart from the already reported inhibition of the PPP by NADPH accumulation, we detected a drastic reduction of the phosphotransferase system (PTS)-mediated glucose uptake in C. glutamicum Δpgi. Furthermore, Northern blot analyses revealed that expression of ptsG, which encodes the glucose-specific EII permease of the PTS, was abolished in this mutant. Applying our findings, we optimized l-lysine production in the model strain C. glutamicum DM1729 by deletion of pgi and overexpression of plasmid-encoded ptsG. l-Lysine yields and productivity with C. glutamicum Δpgi(pBB1-ptsG) were significantly higher than those with C. glutamicum Δpgi(pBB1). These results show that ptsG overexpression is required to overcome the repressed activity of PTS-mediated glucose uptake in pgi-deficient C. glutamicum strains, thus enabling efficient as well as fast l-lysine production.
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Pathways at Work: Metabolic Flux Analysis of the Industrial Cell Factory Corynebacterium glutamicum. CORYNEBACTERIUM GLUTAMICUM 2013. [DOI: 10.1007/978-3-642-29857-8_7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Ye X, Honda K, Morimoto Y, Okano K, Ohtake H. Direct conversion of glucose to malate by synthetic metabolic engineering. J Biotechnol 2012; 164:34-40. [PMID: 23246984 DOI: 10.1016/j.jbiotec.2012.11.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 11/22/2012] [Accepted: 11/27/2012] [Indexed: 11/28/2022]
Abstract
Synthetic metabolic engineering enables us to construct an in vitro artificial synthetic pathways specialized for chemical manufacturing through the simple heat-treatment of the recombinant mesophiles having thermophilic enzymes, followed by rational combination of those biocatalytic modules. In this work, we constructed a synthetic pathway capable of direct conversion of glucose to malate. The reversible carboxylation of pyruvate catalyzed by a malic enzyme derived from Thermococcus kodakarensis (TkME) (ΔG°'=+7.3kJmol(-1)) was coupled with a thermodynamically favorable non-ATP-forming Embden-Meyerhof pathway to balance the consumption and regeneration of redox cofactors and to shift the overall equilibrium toward malate production (glucose+2HCO3(-)+2H→2 malate+2H2O; ΔG°'=-121.4kJmol(-1)). TkME exhibited both pyruvate carboxylation (malate-forming) and pyruvate reduction (lactate-forming) activities. By increasing HCO3(-) concentration, the reaction specificity could be redirected to malate production. As a result, the direct conversion of glucose to malate was achieved with a molar yield of 60%.
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Affiliation(s)
- Xiaoting Ye
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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The Gluconeogenic Pathway in a Soil Mycobacterium Isolate with Bioremediation Ability. Curr Microbiol 2012; 66:122-31. [DOI: 10.1007/s00284-012-0248-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Accepted: 09/23/2012] [Indexed: 11/26/2022]
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Regulation of the malic enzyme gene malE by the transcriptional regulator MalR in Corynebacterium glutamicum. J Biotechnol 2012; 159:204-15. [DOI: 10.1016/j.jbiotec.2012.01.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 12/22/2011] [Accepted: 01/04/2012] [Indexed: 11/18/2022]
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Impact of malic enzymes on antibiotic and triacylglycerol production in Streptomyces coelicolor. Appl Environ Microbiol 2012; 78:4571-9. [PMID: 22544242 DOI: 10.1128/aem.00838-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this paper, we have characterized two malic enzymes (ME), SCO2951 and SCO5261, from Streptomyces coelicolor and analyzed their role in antibiotic and triacylglycerol (TAG) production. Biochemical studies have demonstrated that Sco2951 and Sco5261 genes encode NAD(+)- and NADP(+)-dependent malic enzymes, respectively. Single or double mutants in the ME-encoding genes show no effect on growth rate compared to the parental M145 strain. However, the single Sco2951 and the double Sco2951 Sco5261 mutants display a strong reduction in the production of the polyketide antibiotic actinorhodin; additionally, the Sco2951 Sco5261 mutant shows a decrease in stored TAGs during exponential growth. The lower production of actinorhodin in the double mutant occurs as a consequence of a decrease in the expression of actII-ORF4, the transcriptional activator of the actinorhodin gene cluster. On the other hand, the reduced TAG accumulation is not due to reduced transcript levels of fatty acid biosynthetic genes nor to changes in the amount of the precursor acetyl coenzyme A (acetyl-CoA). This mutant accumulates intermediates of the tricarboxylic acid (TCA) cycle that could alter the regulation of the actinorhodin biosynthetic pathway, suggesting that MEs are important anaplerotic enzymes that redirect C4 intermediates from the TCA cycle to maintain secondary metabolism and TAG production in Streptomyces.
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Abstract
L-threonine, one of the three major amino acids produced throughout the world, has a wide application in industry, as an additive or as a precursor for the biosynthesis of other chemicals. It is predominantly produced through microbial fermentation the efficiency of which largely depends on the quality of strains. Metabolic engineering based on a cogent understanding of the metabolic pathways of L-threonine biosynthesis and regulation provides an effective alternative to the traditional breeding for strain development. Continuing efforts have been made in revealing the mechanisms and regulation of L-threonine producing strains, as well as in metabolic engineering of suitable organisms whereby genetically-defined, industrially competitive L-threonine producing strains have been successfully constructed. This review focuses on the global metabolic and regulatory networks responsible for L-threonine biosynthesis, the molecular mechanisms of regulation, and the strategies employed in strain engineering.
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Affiliation(s)
- Xunyan Dong
- Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, JiangnanUniversity, Wuxi, 214122, China
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Biochemical properties and physiological roles of NADP-dependent malic enzyme in Escherichia coli. J Microbiol 2011; 49:797-802. [PMID: 22068497 DOI: 10.1007/s12275-011-0487-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 04/25/2011] [Indexed: 10/15/2022]
Abstract
Malic enzymes catalyze the reversible oxidative decarboxylation of L-malate using NAD(P)(+) as a cofactor. NADP-dependent malic enzyme (MaeB) from Escherichia coli MG1655 was expressed and purified as a fusion protein. The molecular weight of MaeB was about 83 kDa, as determined by SDS-PAGE. The recombinant MaeB showed a maximum activity at pH 7.8 and 46°C. MaeB activity was dependent on the presence of Mn(2+) but was strongly inhibited by Zn(2+). In order to understand the physiological roles, recombinant E. coli strains (icd (NADP)/ΔmaeB and icd (NAD)/ΔmaeB) containing NADP-dependent isocitrate dehydrogenase (IDH), or engineered NAD-dependent IDH with the deletion of the maeB gene, were constructed using homologous recombination. During growth on acetate, icd (NAD)/ΔmaeB grew poorly, having a growth rate only 60% that of the wild-type strain (icd (NADP)). Furthermore, icd (NADP)/ΔmaeB exhibited a 2-fold greater adaptability to acetate than icd (NAD)/ΔmaeB, which may be explained by more NADPH production for biosynthesis in icd (NADP)/ΔmaeB due to its NADP-dependent IDH. These results indicated that MaeB was important for NADPH production for bacterial growth on acetate. We also observed that MaeB activity was significantly enhanced (7.83-fold) in icd (NAD), which was about 3-fold higher than that in icd (NADP), when switching from glucose to acetate. The marked increase of MaeB activity was probably induced by the shortage of NADPH in icd (NAD). Evidently, MaeB contributed to the NADPH generation needed for bacterial growth on two carbon compounds.
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Lira-Silva E, Ramírez-Lima IS, Olín-Sandoval V, García-García JD, García-Contreras R, Moreno-Sánchez R, Jasso-Chávez R. Removal, accumulation and resistance to chromium in heterotrophic Euglena gracilis. JOURNAL OF HAZARDOUS MATERIALS 2011; 193:216-224. [PMID: 21831522 DOI: 10.1016/j.jhazmat.2011.07.056] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 06/16/2011] [Accepted: 07/13/2011] [Indexed: 05/31/2023]
Abstract
The removal, uptake and toxicity of chromium in Euglena gracilis cultured in absence and presence of malate with Cr(VI) or Cr(III) was evaluated. The malate extrusion and the extra- and intracellular Cr(VI) reduction capacity were determined and the contents of molecules with thiol group and ascorbate were also evaluated. Absence of malate in the medium decreased cell growth, increased Cr(III) toxicity, induced faster Cr(VI) disappearance from medium, and increased intracellular and intramitochondrial chromium accumulation. Both chromium species induced soluble and particulate ascorbate-dependent chromate reductase activities. Cells also secreted large amounts of malate and increased intracellular contents of thiol-molecules to bind extracellular and intracellular Cr(III), respectively. The former process was supported by significant increase in malate-producing enzyme activities and the assessment of the Cr-complexes indicated the in situ formation with thiol-molecules. The present results establish new paradigms regarding chromium stress on algae-like microorganisms: (i) Cr(III) may be more toxic than Cr(VI), depending on the culture (or environmental) conditions; (ii) several simultaneous mechanisms are turned on to inactivate chromium species and their toxic effects. These mechanisms, now well understood may further optimize, by genetically modifying E. gracilis, and facilitate the development of strategies for using this protist as potential bio-remediator of chromium-polluted water systems.
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Affiliation(s)
- Elizabeth Lira-Silva
- Departamento de Bioquímica, Instituto Nacional de Cardiología, Juan Badiano # 1, Sección XVI, Tlalpan, México DF 14080, Mexico
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Beste DJV, Bonde B, Hawkins N, Ward JL, Beale MH, Noack S, Nöh K, Kruger NJ, Ratcliffe RG, McFadden J. ¹³C metabolic flux analysis identifies an unusual route for pyruvate dissimilation in mycobacteria which requires isocitrate lyase and carbon dioxide fixation. PLoS Pathog 2011; 7:e1002091. [PMID: 21814509 PMCID: PMC3141028 DOI: 10.1371/journal.ppat.1002091] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 04/13/2011] [Indexed: 11/19/2022] Open
Abstract
Mycobacterium tuberculosis requires the enzyme isocitrate lyase (ICL) for growth and virulence in vivo. The demonstration that M. tuberculosis also requires ICL for survival during nutrient starvation and has a role during steady state growth in a glycerol limited chemostat indicates a function for this enzyme which extends beyond fat metabolism. As isocitrate lyase is a potential drug target elucidating the role of this enzyme is of importance; however, the role of isocitrate lyase has never been investigated at the level of in vivo fluxes. Here we show that deletion of one of the two icl genes impairs the replication of Mycobacterium bovis BCG at slow growth rate in a carbon limited chemostat. In order to further understand the role of isocitrate lyase in the central metabolism of mycobacteria the effect of growth rate on the in vivo fluxes was studied for the first time using ¹³C-metabolic flux analysis (MFA). Tracer experiments were performed with steady state chemostat cultures of BCG or M. tuberculosis supplied with ¹³C labeled glycerol or sodium bicarbonate. Through measurements of the ¹³C isotopomer labeling patterns in protein-derived amino acids and enzymatic activity assays we have identified the activity of a novel pathway for pyruvate dissimilation. We named this the GAS pathway because it utilizes the Glyoxylate shunt and Anapleurotic reactions for oxidation of pyruvate, and Succinyl CoA synthetase for the generation of succinyl CoA combined with a very low flux through the succinate--oxaloacetate segment of the tricarboxylic acid cycle. We confirm that M. tuberculosis can fix carbon from CO₂ into biomass. As the human host is abundant in CO₂ this finding requires further investigation in vivo as CO₂ fixation may provide a point of vulnerability that could be targeted with novel drugs. This study also provides a platform for further studies into the metabolism of M. tuberculosis using ¹³C-MFA.
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Affiliation(s)
- Dany J. V. Beste
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, United Kingdom
| | - Bhushan Bonde
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, United Kingdom
| | - Nathaniel Hawkins
- Rothamsted Research, National Centre for Plant and Microbial Metabolomics, Harpenden, Herts, United Kingdom
| | - Jane L. Ward
- Rothamsted Research, National Centre for Plant and Microbial Metabolomics, Harpenden, Herts, United Kingdom
| | - Michael H. Beale
- Rothamsted Research, National Centre for Plant and Microbial Metabolomics, Harpenden, Herts, United Kingdom
| | - Stephan Noack
- Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences 1: Biotechnology 2, Jülich, Germany
| | - Katharina Nöh
- Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences 1: Biotechnology 2, Jülich, Germany
| | - Nicholas J. Kruger
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
| | | | - Johnjoe McFadden
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, United Kingdom
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Lindner SN, Seibold GM, Henrich A, Krämer R, Wendisch VF. Phosphotransferase system-independent glucose utilization in corynebacterium glutamicum by inositol permeases and glucokinases. Appl Environ Microbiol 2011; 77:3571-81. [PMID: 21478323 PMCID: PMC3127631 DOI: 10.1128/aem.02713-10] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Accepted: 03/26/2011] [Indexed: 12/30/2022] Open
Abstract
Phosphoenolpyruvate-dependent glucose phosphorylation via the phosphotransferase system (PTS) is the major path of glucose uptake in Corynebacterium glutamicum, but some growth from glucose is retained in the absence of the PTS. The growth defect of a deletion mutant lacking the general PTS component HPr in glucose medium could be overcome by suppressor mutations leading to the high expression of inositol utilization genes or by the addition of inositol to the growth medium if a glucokinase is overproduced simultaneously. PTS-independent glucose uptake was shown to require at least one of the inositol transporters IolT1 and IolT2 as a mutant lacking IolT1, IolT2, and the PTS component HPr could not grow with glucose as the sole carbon source. Efficient glucose utilization in the absence of the PTS necessitated the overexpression of a glucokinase gene in addition to either iolT1 or iolT2. IolT1 and IolT2 are low-affinity glucose permeases with K(s) values of 2.8 and 1.9 mM, respectively. As glucose uptake and phosphorylation via the PTS differs from glucose uptake via IolT1 or IolT2 and phosphorylation via glucokinase by the requirement for phosphoenolpyruvate, the roles of the two pathways for l-lysine production were tested. The l-lysine yield by C. glutamicum DM1729, a rationally engineered l-lysine-producing strain, was lower than that by its PTS-deficient derivate DM1729Δhpr, which, however, showed low production rates. The combined overexpression of iolT1 or iolT2 with ppgK, the gene for PolyP/ATP-dependent glucokinase, in DM1729Δhpr enabled l-lysine production as fast as that by the parent strain DM1729 but with 10 to 20% higher l-lysine yield.
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Affiliation(s)
- Steffen N. Lindner
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, D-33501 Bielefeld, Germany
| | - Gerd M. Seibold
- Institute of Biochemistry, University of Cologne, D-50674 Cologne, Germany
| | - Alexander Henrich
- Institute of Biochemistry, University of Cologne, D-50674 Cologne, Germany
| | - Reinhard Krämer
- Institute of Biochemistry, University of Cologne, D-50674 Cologne, Germany
| | - Volker F. Wendisch
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, D-33501 Bielefeld, Germany
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Corynebacterium glutamicum tailored for efficient isobutanol production. Appl Environ Microbiol 2011; 77:3300-10. [PMID: 21441331 DOI: 10.1128/aem.02972-10] [Citation(s) in RCA: 215] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We recently engineered Corynebacterium glutamicum for aerobic production of 2-ketoisovalerate by inactivation of the pyruvate dehydrogenase complex, pyruvate:quinone oxidoreductase, transaminase B, and additional overexpression of the ilvBNCD genes, encoding acetohydroxyacid synthase, acetohydroxyacid isomeroreductase, and dihydroxyacid dehydratase. Based on this strain, we engineered C. glutamicum for the production of isobutanol from glucose under oxygen deprivation conditions by inactivation of l-lactate and malate dehydrogenases, implementation of ketoacid decarboxylase from Lactococcus lactis, alcohol dehydrogenase 2 (ADH2) from Saccharomyces cerevisiae, and expression of the pntAB transhydrogenase genes from Escherichia coli. The resulting strain produced isobutanol with a substrate-specific yield (Y(P/S)) of 0.60 ± 0.02 mol per mol of glucose. Interestingly, a chromosomally encoded alcohol dehydrogenase rather than the plasmid-encoded ADH2 from S. cerevisiae was involved in isobutanol formation with C. glutamicum, and overexpression of the corresponding adhA gene increased the Y(P/S) to 0.77 ± 0.01 mol of isobutanol per mol of glucose. Inactivation of the malic enzyme significantly reduced the Y(P/S), indicating that the metabolic cycle consisting of pyruvate and/or phosphoenolpyruvate carboxylase, malate dehydrogenase, and malic enzyme is responsible for the conversion of NADH + H+ to NADPH + H+. In fed-batch fermentations with an aerobic growth phase and an oxygen-depleted production phase, the most promising strain, C. glutamicum ΔaceE Δpqo ΔilvE ΔldhA Δmdh(pJC4ilvBNCD-pntAB)(pBB1kivd-adhA), produced about 175 mM isobutanol, with a volumetric productivity of 4.4 mM h⁻¹, and showed an overall Y(P/S) of about 0.48 mol per mol of glucose in the production phase.
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Neuner A, Heinzle E. Mixed glucose and lactate uptake by Corynebacterium glutamicum through metabolic engineering. Biotechnol J 2011; 6:318-29. [DOI: 10.1002/biot.201000307] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Tang W, Zhang S, Tan H, Zhao ZK. Molecular cloning and characterization of a malic enzyme gene from the oleaginous yeast Lipomyces starkeyi. Mol Biotechnol 2010; 45:121-8. [PMID: 20217282 DOI: 10.1007/s12033-010-9255-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The malic enzyme-encoding cDNA (GQ372891) from the oleaginous yeast Lipomyces starkeyi AS 2.1560 was isolated, which has an 1719-bp open reading frame flanked by a 290-bp 5' untranslated sequence and a 92-bp 3' untranslated sequence. The proposed gene, LsME1, encoded a protein with 572 amino acid residues. The protein presented 58% sequence identity with the malic enzymes from Yarrowia lipolytica CLIB122 and Aspergillus fumigatus Af293. The LsME1 gene was cloned into the vector pMAL-p4x to express a fusion protein (MBP-LsME1) in Escherichia coli TB1. The fusion protein was purified and then cleaved by Factor Xa to give the recombinant LsME1. This purified enzyme took either NAD(+) or NADP(+) as the coenzyme but preferred NAD(+). The K (m) values for malic acid, NAD(+) and NADP(+) were 0.85 +/- 0.05 mM, 0.34 +/- 0.08 mM, and 7.4 +/- 0.32 mM, respectively, at pH 7.3.
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Affiliation(s)
- Wei Tang
- Dalian Institute of Chemical Physics, CAS, Dalian 116023, People's Republic of China
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Bartek T, Blombach B, Zönnchen E, Makus P, Lang S, Eikmanns BJ, Oldiges M. Importance of NADPH supply for improved L-valine formation in Corynebacterium glutamicum. Biotechnol Prog 2010; 26:361-71. [PMID: 20014412 DOI: 10.1002/btpr.345] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cofactor recycling is known to be crucial for amino acid synthesis. Hence, cofactor supply was now analyzed for L-valine to identify new targets for an improvement of production. The central carbon metabolism was analyzed by stoichiometric modeling to estimate the influence of cofactors and to quantify the theoretical yield of L-valine on glucose. Three different optimal routes for L-valine biosynthesis were identified by elementary mode (EM) analysis. The modes differed mainly in the manner of NADPH regeneration, substantiating that the cofactor supply may be crucial for efficient L-valine production. Although the isocitrate dehydrogenase as an NADPH source within the tricarboxylic acid cycle only enables an L-valine yield of Y(Val/Glc) = 0.5 mol L-valine/mol glucose (mol Val/mol Glc), the pentose phosphate pathway seems to be the most promising NADPH source. Based on the theoretical calculation of EMs, the gene encoding phosphoglucoisomerase (PGI) was deleted to achieve this EM with a theoretical yield Y(Val/Glc) = 0.86 mol Val/mol Glc during the production phase. The intracellular NADPH concentration was significantly increased in the PGI-deficient mutant. L-Valine yield increased from 0.49 +/- 0.13 to 0.67 +/- 0.03 mol Val/mol Glc, and, concomitantly, the formation of by-products such as pyruvate was reduced.
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Affiliation(s)
- Tobias Bartek
- Institute of Biotechnology 2, Forschungszentrum Jülich, Jülich 52425, Germany
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Klaffl S, Eikmanns BJ. Genetic and functional analysis of the soluble oxaloacetate decarboxylase from Corynebacterium glutamicum. J Bacteriol 2010; 192:2604-12. [PMID: 20233922 PMCID: PMC2863558 DOI: 10.1128/jb.01678-09] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Accepted: 03/07/2010] [Indexed: 11/20/2022] Open
Abstract
Soluble, divalent cation-dependent oxaloacetate decarboxylases (ODx) catalyze the irreversible decarboxylation of oxaloacetate to pyruvate and CO(2). Although these enzymes have been characterized in different microorganisms, the genes that encode them have not been identified, and their functions have been only poorly analyzed so far. In this study, we purified a soluble ODx from wild-type C. glutamicum about 65-fold and used matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analysis and peptide mass fingerprinting for identification of the corresponding odx gene. Inactivation and overexpression of odx led to an absence of ODx activity and to a 30-fold increase in ODx specific activity, respectively; these findings unequivocally confirmed that this gene encodes a soluble ODx. Transcriptional analysis of odx indicated that there is a leaderless transcript that is organized in an operon together with a putative S-adenosylmethionine-dependent methyltransferase gene. Biochemical analysis of ODx revealed that the molecular mass of the native enzyme is about 62 +/- 1 kDa and that the enzyme is composed of two approximately 29-kDa homodimeric subunits and has a K(m) for oxaloacetate of 1.4 mM and a V(max) of 201 micromol of oxaloacetate converted per min per mg of protein, resulting in a k(cat) of 104 s(-1). Introduction of plasmid-borne odx into a pyruvate kinase-deficient C. glutamicum strain restored growth of this mutant on acetate, indicating that a high level of ODx activity redirects the carbon flux from oxaloacetate to pyruvate in vivo. Consistently, overexpression of the odx gene in an L-lysine-producing strain of C. glutamicum led to accumulation of less L-lysine. However, inactivation of the odx gene did not improve L-lysine production under the conditions tested.
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Affiliation(s)
- Simon Klaffl
- Institute of Microbiology and Biotechnology, University of Ulm, D-89069 Ulm, Germany
| | - Bernhard J. Eikmanns
- Institute of Microbiology and Biotechnology, University of Ulm, D-89069 Ulm, Germany
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Lindner SN, Niederholtmeyer H, Schmitz K, Schoberth SM, Wendisch VF. Polyphosphate/ATP-dependent NAD kinase of Corynebacterium glutamicum: biochemical properties and impact of ppnK overexpression on lysine production. Appl Microbiol Biotechnol 2010; 87:583-93. [PMID: 20180116 DOI: 10.1007/s00253-010-2481-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 01/28/2010] [Accepted: 01/28/2010] [Indexed: 11/24/2022]
Abstract
Nicotinamide adenine dinucleotide phosphate (NADP) is synthesized by phosphorylation of either oxidized or reduced nicotinamide adenine dinucleotide (NAD/NADH). Here, the cg1601/ppnK gene product from Corynebacterium glutamicum genome was purified from recombinant Escherichia coli and enzymatic characterization revealed its activity as a polyphosphate (PolyP)/ATP-dependent NAD kinase (PPNK). PPNK from C. glutamicum was shown to be active as homotetramer accepting PolyP, ATP, and even ADP for phosphorylation of NAD. The catalytic efficiency with ATP as phosphate donor for phosphorylation of NAD was higher than with PolyP. With respect to the chain length of PolyP, PPNK was active with short-chain PolyPs. PPNK activity was independent of bivalent cations when using ATP, but was enhanced by manganese and in particular by magnesium ions. When using PolyP, PPNK required bivalent cations, preferably manganese ions, for activity. PPNK was inhibited by NADP and NADH at concentrations below millimolar. Overexpression of ppnK in C. glutamicum wild type slightly reduced growth and ppnK overexpression in the lysine producing strain DM1729 resulted in a lysine product yield on glucose of 0.136 +/- 0.006 mol lysine (mol glucose)(-1), which was 12% higher than that of the empty vector control strain.
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Affiliation(s)
- Steffen N Lindner
- Institute of Molecular Microbiology and Biotechnology, Westfalian Wilhelms University Muenster, 48149, Muenster, Germany
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Wittmann C. Analysis and engineering of metabolic pathway fluxes in Corynebacterium glutamicum. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2010; 120:21-49. [PMID: 20140657 DOI: 10.1007/10_2009_58] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The Gram-positive soil bacterium Corynebacterium glutamicum was discovered as a natural overproducer of glutamate about 50 years ago. Linked to the steadily increasing economical importance of this microorganism for production of glutamate and other amino acids, the quest for efficient production strains has been an intense area of research during the past few decades. Efficient production strains were created by applying classical mutagenesis and selection and especially metabolic engineering strategies with the advent of recombinant DNA technology. Hereby experimental and computational approaches have provided fascinating insights into the metabolism of this microorganism and directed strain engineering. Today, C. glutamicum is applied to the industrial production of more than 2 million tons of amino acids per year. The huge achievements in recent years, including the sequencing of the complete genome and efficient post genomic approaches, now provide the basis for a new, fascinating era of research - analysis of metabolic and regulatory properties of C. glutamicum on a global scale towards novel and superior bioprocesses.
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Affiliation(s)
- Christoph Wittmann
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Gaussstrasse 17, 38106, Braunschweig, Germany,
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Permeabilization of Corynebacterium glutamicum for NAD(P)H-dependent intracellular enzyme activity measurement. CR CHIM 2009. [DOI: 10.1016/j.crci.2009.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Buchinger S, Strösser J, Rehm N, Hänssler E, Hans S, Bathe B, Schomburg D, Krämer R, Burkovski A. A combination of metabolome and transcriptome analyses reveals new targets of the Corynebacterium glutamicum nitrogen regulator AmtR. J Biotechnol 2008; 140:68-74. [PMID: 19041910 DOI: 10.1016/j.jbiotec.2008.10.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 09/30/2008] [Accepted: 10/21/2008] [Indexed: 10/21/2022]
Abstract
The effects of a deletion of the amtR gene, encoding the master regulator of nitrogen control in Corynebacterium glutamicum, were investigated by metabolome and transcriptome analyses. Compared to the wild type, different metabolite patterns were observed in respect to glycolysis, pentose phosphate pathway, citric acid cycle, and most amino acid pools. Not all of these alterations could be attributed to changes at the level of mRNA and must be caused by posttranscriptional regulatory processes. However, subsequently carried out transcriptome analyses, which were confirmed by gel retardation experiments, revealed two new targets of AmtR, the dapD gene, encoding succinylase involved in m-diaminopimelate synthesis, and the mez gene, coding for malic enzyme. The regulation of dapD connects the AmtR-dependent nitrogen control with l-lysine biosynthesis, the regulation of mez with carbon metabolism. An increased l-glutamine pool in the amtR mutant compared to the wild type was correlated with deregulated expression of the AmtR-regulated glnA gene and an increased glutamine synthetase activity. The glutamate pool was decreased in the mutant and also glutamate excretion was impaired.
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Blombach B, Schreiner ME, Bartek T, Oldiges M, Eikmanns BJ. Corynebacterium glutamicum tailored for high-yield L-valine production. Appl Microbiol Biotechnol 2008; 79:471-9. [DOI: 10.1007/s00253-008-1444-z] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 02/29/2008] [Accepted: 03/02/2008] [Indexed: 10/22/2022]
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Han SO, Inui M, Yukawa H. Expression of Corynebacterium glutamicum glycolytic genes varies with carbon source and growth phase. MICROBIOLOGY-SGM 2007; 153:2190-2202. [PMID: 17600063 DOI: 10.1099/mic.0.2006/004366-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A basic pattern of gene expression and of relative expression levels during different growth phases was obtained for Corynebacterium glutamicum R grown on different carbon sources. The gapA-pgk-tpi-ppc gene cluster was transcribed as a mono- or polycistronic mRNA, depending on the growth phase. The 1.4 kb (gapA) and 2.3 kb (pgk-tip) mRNAs were expressed in the early through late exponential phases, whereas the 3.7 kb (gapA-pgk-tpi) and 5.4 kb (pgk-tpi-ppc) mRNAs were only detected in the mid-exponential phase. All other glycolytic genes except pps, glk and pgi were transcribed as monocistronic mRNAs under all tested conditions. Identification and alignment of the promoter regions of the transcriptional start sites of glycolytic genes revealed strong similarities to the sigma(A) consensus promoter sequences of Gram-positive bacteria. All genes involved in glycolysis were coordinately expressed in medium containing glucose. Growth in the presence of glucose gave rise to abundant expression of most glycolytic genes, with the level of gapA transcript being the highest. Glucose depletion led to a rapid repression of most glycolytic genes and a corresponding two- to fivefold increased expression of the gluconeogenic genes pps, pck and malE, which are induced by pyruvate, lactate, acetate and/or other organic acids.
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Affiliation(s)
- Sung Ok Han
- School of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-gu, Seoul, Republic of Korea
- Research Institute of Innovative Technology for the Earth, Kyoto 619-0292, Japan
| | - Masayuki Inui
- Research Institute of Innovative Technology for the Earth, Kyoto 619-0292, Japan
| | - Hideaki Yukawa
- Research Institute of Innovative Technology for the Earth, Kyoto 619-0292, Japan
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Growth characteristics of Brevibacterium, Corynebacterium, Microbacterium, and Staphylococcus spp. isolated from surface-ripened cheese. Appl Environ Microbiol 2007; 73:7732-9. [PMID: 17921266 DOI: 10.1128/aem.01260-07] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The growth characteristics of five bacteria, Brevibacterium aurantiacum 1-16-58, Corynebacterium casei DPC 5298(T), Corynebacterium variabile DPC 5310, Microbacterium gubbeenense DPC 5286(T), and Staphylococcus saprophyticus 4E61, all of which were isolated from the surface of smear cheese, were studied in complex and chemically defined media. All of the coryneforms, except M. gubbeenense, grew in 12% salt, while B. aurantiacum and S. saprophyticus grew in 15% salt. All five bacteria assimilated lactate in a semisynthetic medium, and none of the coryneform bacteria assimilated lactose. Glucose assimilation was poor, except by S. saprophyticus and C. casei. Five to seven amino acids were assimilated by the coryneforms and 12 by S. saprophyticus. Glutamate, phenylalanine, and proline were utilized by all five bacteria, whereas utilization of serine, threonine, aspartate, histidine, alanine, arginine, leucine, isoleucine, and glycine depended on the organism. Growth of C. casei restarted after addition of glutamate, proline, serine, and lactate at the end of the exponential phase, indicating that these amino acids and lactate can be used as energy sources. Pantothenic acid was essential for the growth of C. casei and M. gubbeenense. Omission of biotin reduced the growth of B. aurantiacum, C. casei, and M. gubbeenense. All of the bacteria contained lactate dehydrogenase activity (with both pyruvate and lactate as substrates) and glutamate pyruvate transaminase activity but not urease activity.
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Shirai T, Fujimura K, Furusawa C, Nagahisa K, Shioya S, Shimizu H. Study on roles of anaplerotic pathways in glutamate overproduction of Corynebacterium glutamicum by metabolic flux analysis. Microb Cell Fact 2007; 6:19. [PMID: 17587457 PMCID: PMC1919393 DOI: 10.1186/1475-2859-6-19] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Accepted: 06/23/2007] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Corynebacterium glutamicum has several anaplerotic pathways (anaplerosis), which are essential for the productions of amino acids, such as lysine and glutamate. It is still not clear how flux changes in anaplerotic pathways happen when glutamate production is induced by triggers, such as biotin depletion and the addition of the detergent material, Tween 40. In this study, we quantitatively analyzed which anaplerotic pathway flux most markedly changes the glutamate overproduction induced by Tween 40 addition. RESULTS We performed a metabolic flux analysis (MFA) with [1-13C]- and [U-13C]-labeled glucose in the glutamate production phase of C. glutamicum, based on the analysis of the time courses of 13C incorporation into proteinogenic amino acids by gas chromatography-mass spectrometry (GC-MS). The flux from phosphoenolpyruvate (PEP) to oxaloacetate (Oxa) catalyzed by phosphoenolpyruvate carboxylase (PEPc) was active in the growth phase not producing glutamate, whereas that from pyruvate to Oxa catalyzed by pyruvate carboxylase (Pc) was inactive. In the glutamate overproduction phase induced by the addition of the detergent material Tween 40, the reaction catalyzed by Pc also became active in addition to the reaction catalyzed by PEPc. CONCLUSION It was clarified by a quantitative 13C MFA that the reaction catalyzed by Pc is most markedly increased, whereas other fluxes of PEPc and PEPck remain constant in the glutamate overproduction induced by Tween 40. This result is consistent with the previous results obtained in a comparative study on the glutamate productions of genetically recombinant Pc- and PEPc-overexpressing strains. The importance of a specific reaction in an anaplerotic pathway was elucidated at a metabolic level by MFA.
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Affiliation(s)
- Tomokazu Shirai
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Japan
| | - Koki Fujimura
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Japan
| | - Chikara Furusawa
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Japan
| | - Keisuke Nagahisa
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Japan
| | - Suteaki Shioya
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Japan
| | - Hiroshi Shimizu
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Japan
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