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Li Y, Guo Y, Niu F, Gao H, Wang Q, Xu M. Regulation of oxidative stress response and antioxidant modification in Corynebacterium glutamicum. World J Microbiol Biotechnol 2024; 40:267. [PMID: 39004689 DOI: 10.1007/s11274-024-04066-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Accepted: 06/27/2024] [Indexed: 07/16/2024]
Abstract
As an efficient and safe industrial bacterium, Corynebacterium glutamicum has extensive application in amino acid production. However, it often faces oxidative stress induced by reactive oxygen species (ROS), leading to diminished production efficiency. To enhance the robustness of C. glutamicum, numerous studies have focused on elucidating its regulatory mechanisms under various stress conditions such as heat, acid, and sulfur stress. However, a comprehensive review of its defense mechanisms against oxidative stress is needed. This review offers an in-depth overview of the mechanisms C. glutamicum employs to manage oxidative stress. It covers both enzymatic and non-enzymatic systems, including antioxidant enzymes, regulatory protein families, sigma factors involved in transcription, and physiological redox reduction pathways. This review provides insights for advancing research on the antioxidant mechanisms of C. glutamicum and sheds light on its potential applications in industrial production.
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Affiliation(s)
- Yueshu Li
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Yuanyi Guo
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Fangyuan Niu
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Hui Gao
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Qing Wang
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Meijuan Xu
- The Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.
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Busche T, Dostálová H, Rucká L, Holátko J, Barvík I, Štěpánek V, Pátek M, Kalinowski J. Overlapping SigH and SigE sigma factor regulons in Corynebacterium glutamicum. Front Microbiol 2022; 13:1059649. [PMID: 36925999 PMCID: PMC10012870 DOI: 10.3389/fmicb.2022.1059649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 11/15/2022] [Indexed: 03/06/2023] Open
Abstract
The sigma H (σΗ) and sigma E (σE) subunits of Corynebacterium glutamicum RNA polymerase belong to Group 4 of sigma factors, also called extracytoplasmic function (ECF) sigma factors. Genes of the C. glutamicum σΗ regulon that are involved in heat and oxidative stress response have already been defined, whereas the genes of the σE regulon, which is involved in cell surface stress response, have not been explored until now. Using the C. glutamicum RES167 strain and its derivative C. glutamicum ΔcseE with a deletion in the anti-σΕ gene, differential gene expression was analyzed by RNA sequencing. We found 296 upregulated and 398 downregulated genes in C. glutamicum ΔcseE compared to C. glutamicum RES167. To confirm the functional link between σΕ and the corresponding promoters, we tested selected promoters using the in vivo two-plasmid system with gfpuv as a reporter gene and by in vitro transcription. Analyses with RNAP+σΗ and RNAP+σΕ, which were previously shown to recognize similar promoters, proved that the σΗ and σE regulons significantly overlap. The σE-controlled genes were found to be involved for example in protein quality control (dnaK, dnaJ2, clpB, and clpC), the regulation of Clp proteases (clgR), and membrane integrity maintenance. The single-promoter analyses with σΗ and σΕ revealed that there are two groups of promoters: those which are exclusively σΗ-specific, and the other group of promoters, which are σΗ/σE-dependent. No exclusively σE-dependent promoter was detected. We defined the consensus sequences of exclusively σΗ-regulated promotors to be -35 GGAAt and - 10 GTT and σΗ/σE-regulated promoters to be -35 GGAAC and - 10 cGTT. Fifteen genes were found to belong to the σΗ/σΕ regulon. Homology modeling showed that there is a specific interaction between Met170 in σΗ and the nucleotides -31 and - 30 within the non-coding strand (AT or CT) of the σΗ-dependent promoters. In σE, Arg185 was found to interact with the nucleotides GA at the same positions in the σE-dependent promoters.
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Affiliation(s)
- Tobias Busche
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany.,Medical School East Westphalia-Lippe, Bielefeld University, Bielefeld, Germany
| | - Hana Dostálová
- Institute of Microbiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Lenka Rucká
- Institute of Microbiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Jiří Holátko
- Institute of Microbiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Ivan Barvík
- Faculty of Mathematics and Physics, Institute of Physics, Charles University, Prague, Czechia
| | - Václav Štěpánek
- Institute of Microbiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Miroslav Pátek
- Institute of Microbiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
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Toyoda K, Inui M. The ldhA Gene Encoding Fermentative l-Lactate Dehydrogenase in Corynebacterium Glutamicum Is Positively Regulated by the Global Regulator GlxR. Microorganisms 2021; 9:microorganisms9030550. [PMID: 33800875 PMCID: PMC7999487 DOI: 10.3390/microorganisms9030550] [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: 02/01/2021] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 11/24/2022] Open
Abstract
Bacterial metabolism shifts from aerobic respiration to fermentation at the transition from exponential to stationary growth phases in response to limited oxygen availability. Corynebacterium glutamicum, a Gram-positive, facultative aerobic bacterium used for industrial amino acid production, excretes l-lactate, acetate, and succinate as fermentation products. The ldhA gene encoding l-lactate dehydrogenase is solely responsible for l-lactate production. Its expression is repressed at the exponential phase and prominently induced at the transition phase. ldhA is transcriptionally repressed by the sugar-phosphate-responsive regulator SugR and l-lactate-responsive regulator LldR. Although ldhA expression is derepressed even at the exponential phase in the sugR and lldR double deletion mutant, a further increase in its expression is still observed at the stationary phase, implicating the action of additional transcription regulators. In this study, involvement of the cAMP receptor protein-type global regulator GlxR in the regulation of ldhA expression was investigated. The GlxR-binding site found in the ldhA promoter was modified to inhibit or enhance binding of GlxR. The ldhA promoter activity and expression of ldhA were altered in proportion to the binding affinity of GlxR. Similarly, l-lactate production was also affected by the binding site modification. Thus, GlxR was demonstrated to act as a transcriptional activator of ldhA.
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Affiliation(s)
- Koichi Toyoda
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan;
| | - Masayuki Inui
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan;
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
- Correspondence:
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Jojima T, Igari T, Noburyu R, Watanabe A, Suda M, Inui M. Coexistence of the Entner-Doudoroff and Embden-Meyerhof-Parnas pathways enhances glucose consumption of ethanol-producing Corynebacterium glutamicum. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:45. [PMID: 33593398 PMCID: PMC7888142 DOI: 10.1186/s13068-021-01876-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 01/07/2021] [Indexed: 05/09/2023]
Abstract
BACKGROUND It is interesting to modify sugar metabolic pathways to improve the productivity of biocatalysts that convert sugars to value-added products. However, this attempt often fails due to the tight control of the sugar metabolic pathways. Recently, activation of the Entner-Doudoroff (ED) pathway in Escherichia coli has been shown to enhance glucose consumption, though the mechanism underlying this phenomenon is poorly understood. In the present study, we investigated the effect of a functional ED pathway in metabolically engineered Corynebacterium glutamicum that metabolizes glucose via the Embden-Meyerhof-Parnas (EMP) pathway to produce ethanol under oxygen deprivation. This study aims to provide further information on metabolic engineering strategies that allow the Entner-Doudoroff and Embden-Meyerhof-Parnas pathways to coexist. RESULTS Three genes (zwf, edd, and eda) encoding glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydratase, and 2-keto-3-deoxy-6-phosphogluconate aldolase from Zymomonas mobilis were expressed in a genetically modified strain, C. glutamicum CRZ2e, which produces pyruvate decarboxylase and alcohol dehydrogenase from Z. mobilis. A 13C-labeling experiment using [1-13C] glucose indicated a distinctive 13C distribution of ethanol between the parental and the ED-introduced strains, which suggested an alteration of carbon flux as a consequence of ED pathway introduction. The ED-introduced strain, CRZ2e-ED, consumed glucose 1.5-fold faster than the parental strain. A pfkA deletion mutant of CRZ2e-ED (CRZ2e-EDΔpfkA) was also constructed to evaluate the effects of EMP pathway inactivation, which showed an almost identical rate of glucose consumption compared to that of the parental CRZ2e strain. The introduction of the ED pathway did not alter the intracellular NADH/NAD+ ratio, whereas it resulted in a slight increase in the ATP/ADP ratio. The recombinant strains with simultaneous overexpression of the genes for the EMP and ED pathways exhibited the highest ethanol productivity among all C. glutamicum strains ever constructed. CONCLUSIONS The increased sugar consumption observed in ED-introduced strains was not a consequence of cofactor balance alterations, but rather the crucial coexistence of two active glycolytic pathways for enhanced glucose consumption. Coexistence of the ED and EMP pathways is a good strategy for improving biocatalyst productivity even when NADPH supply is not a limiting factor for fermentation.
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Affiliation(s)
- Toru Jojima
- Research Institute of Innovative Technology for the Earth, 9-2, Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan
- Faculty of Agriculture, Department of Environmental Management, Kindai University, 3327-204 Nakamachi, Nara, 631-8505, Japan
| | - Takafumi Igari
- Research Institute of Innovative Technology for the Earth, 9-2, Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan
| | - Ryoji Noburyu
- Research Institute of Innovative Technology for the Earth, 9-2, Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan
| | - Akira Watanabe
- Research Institute of Innovative Technology for the Earth, 9-2, Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan
| | - Masako Suda
- Research Institute of Innovative Technology for the Earth, 9-2, Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan
| | - Masayuki Inui
- Research Institute of Innovative Technology for the Earth, 9-2, Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
- Division of Biological Sciences, Nara Institute of Science and Technology, Takayama, Ikoma, 8916-5, Nara, 630-0101, Japan.
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Jeong H, Lee JH, Kim Y, Lee HS. Thiol-specific oxidant diamide downregulates whiA gene of Corynebacterium glutamicum, thereby suppressing cell division and metabolism. Res Microbiol 2020; 171:331-340. [PMID: 32750493 DOI: 10.1016/j.resmic.2020.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 11/24/2022]
Abstract
The whiA (NCgl1527) gene from Corynebacterium glutamicum plays a crucial role during cell growth, and WhiA is recognized as the transcription factor for genes involved in cell division. In this study, we assessed the regulatory role of the gene in cell physiology. Transcription of the gene was specifically downregulated by the thiol-specific oxidant, diamide, and by heat stress. Cells exposed to diamide showed decreased transcription of genes involved in cell division and these effects were more profound in ΔwhiA cells. In addition, the ΔwhiA cells showed sensitivity to thiol-specific oxidants, DNA-damaging agents, and high temperature. Further, downregulation of sigH (NCgl0733), the central regulator in stress responses, along with master regulatory genes in cell metabolism, was observed in the ΔwhiA strain. Moreover, the amount of cAMP in the ΔwhiA cells in the early stationary phase was only at 30% level of that for the wild-type strain. Collectively, our data indicate that the role of whiA is to downregulate genes associated with cell division in response to heat or thiol-specific oxidative stress, and may suggest a role for the gene in downshifting cell metabolism by downregulating global regulatory genes when growth condition is not optimal for cells.
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Affiliation(s)
- Haeri Jeong
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Republic of Korea.
| | - Jae-Hyun Lee
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Republic of Korea.
| | - Younhee Kim
- Department of Korean Medicine, Semyung University, Jecheon, Chungbuk, Republic of Korea.
| | - Heung-Shick Lee
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Republic of Korea.
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Ruwe M, Persicke M, Busche T, Müller B, Kalinowski J. Physiology and Transcriptional Analysis of (p)ppGpp-Related Regulatory Effects in Corynebacterium glutamicum. Front Microbiol 2019; 10:2769. [PMID: 31849906 PMCID: PMC6892785 DOI: 10.3389/fmicb.2019.02769] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 11/13/2019] [Indexed: 12/20/2022] Open
Abstract
The alarmone species ppGpp and pppGpp are elementary components of bacterial physiology as they both coordinate the bacterial stress response and serve as fine-tuners of general metabolism during conditions of balanced growth. Since the regulation of (p)ppGpp metabolism and the effects of (p)ppGpp on cellular processes are highly complex and show massive differences between bacterial species, the underlying molecular mechanisms have so far only been insufficiently investigated for numerous microorganisms. In this study, (p)ppGpp physiology in the actinobacterial model organism Corynebacterium glutamicum was analyzed by phenotypic characterization and RNAseq-based transcriptome analysis. Total nutrient starvation was identified as the most effective method to induce alarmone production, whereas traditional induction methods such as the addition of serine hydroxamate (SHX) or mupirocin did not show a strong accumulation of (p)ppGpp. The predominant alarmone in C. glutamicum represents guanosine tetraphosphate, whose stress-associated production depends on the presence of the bifunctional RSH enzyme Rel. Interestingly, in addition to ppGpp, another substance yet not identified accumulated strongly under inducing conditions. A C. glutamicum triple mutant (Δrel,ΔrelS,ΔrelH) unable to produce alarmones [(p)ppGpp0 strain] exhibited unstable growth characteristics and interesting features such as an influence of illumination on its physiology, production of amino acids as well as differences in vitamin and carotenoid production. Differential transcriptome analysis using RNAseq provided numerous indications for the molecular basis of the observed phenotype. An evaluation of the (p)ppGpp-dependent transcriptional regulation under total nutrient starvation revealed a complex interplay with the involvement of ribosome-mediated transcriptional attenuation, the stress-responsive sigma factors σB and σH and transcription factors such as McbR, the master regulator of sulfur metabolism. In addition to the differential regulation of genes connected with various cell functions, the transcriptome analysis revealed conserved motifs within the promoter regions of (p)ppGpp-dependently and independently regulated genes. In particular, the representatives of translation-associated genes are both (p)ppGpp-dependent transcriptionally downregulated and show a highly conserved and so far unknown TTTTG motif in the -35 region, which is also present in other actinobacterial genera.
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Affiliation(s)
- Matthias Ruwe
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Marcus Persicke
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Tobias Busche
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | | | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
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7
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Haas T, Graf M, Nieß A, Busche T, Kalinowski J, Blombach B, Takors R. Identifying the Growth Modulon of Corynebacterium glutamicum. Front Microbiol 2019; 10:974. [PMID: 31134020 PMCID: PMC6517550 DOI: 10.3389/fmicb.2019.00974] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 04/18/2019] [Indexed: 12/16/2022] Open
Abstract
The growth rate (μ) of industrially relevant microbes, such as Corynebacterium glutamicum, is a fundamental property that indicates its production capacity. Therefore, understanding the mechanism underlying the growth rate is imperative for improving productivity and performance through metabolic engineering. Despite recent progress in the understanding of global regulatory interactions, knowledge of mechanisms directing cell growth remains fragmented and incomplete. The current study investigated RNA-Seq data of three growth rate transitions, induced by different pre-culture conditions, in order to identify transcriptomic changes corresponding to increasing growth rates. These transitions took place in minimal medium and ranged from 0.02 to 0.4 h-1 μ. This study enabled the identification of 447 genes as components of the growth modulon. Enrichment of genes within the growth modulon revealed 10 regulons exhibiting a significant effect over growth rate transition. In summary, central metabolism was observed to be regulated by a combination of metabolic and transcriptional activities orchestrating control over glycolysis, pentose phosphate pathway, and the tricarboxylic acid cycle. Additionally, major responses to changes in the growth rate were linked to iron uptake and carbon metabolism. In particular, genes encoding glycolytic enzymes and the glucose uptake system showed a positive correlation with the growth rate.
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Affiliation(s)
- Thorsten Haas
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Michaela Graf
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Alexander Nieß
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Tobias Busche
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany.,Institute for Biology-Microbiology, Freie Universität Berlin, Berlin, Germany
| | - Jörn Kalinowski
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Bastian Blombach
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany.,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
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Lange J, Münch E, Müller J, Busche T, Kalinowski J, Takors R, Blombach B. Deciphering the Adaptation of Corynebacterium glutamicum in Transition from Aerobiosis via Microaerobiosis to Anaerobiosis. Genes (Basel) 2018; 9:E297. [PMID: 29899275 PMCID: PMC6027265 DOI: 10.3390/genes9060297] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/31/2018] [Accepted: 06/07/2018] [Indexed: 01/02/2023] Open
Abstract
Zero-growth processes are a promising strategy for the production of reduced molecules and depict a steady transition from aerobic to anaerobic conditions. To investigate the adaptation of Corynebacterium glutamicum to altering oxygen availabilities, we conceived a triple-phase fermentation process that describes a gradual reduction of dissolved oxygen with a shift from aerobiosis via microaerobiosis to anaerobiosis. The distinct process phases were clearly bordered by the bacteria’s physiologic response such as reduced growth rate, biomass substrate yield and altered yield of fermentation products. During the process, sequential samples were drawn at six points and analyzed via RNA-sequencing, for metabolite concentrations and for enzyme activities. We found transcriptional alterations of almost 50% (1421 genes) of the entire protein coding genes and observed an upregulation of fermentative pathways, a rearrangement of respiration, and mitigation of the basic cellular mechanisms such as transcription, translation and replication as a transient response related to the installed oxygen dependent process phases. To investigate the regulatory regime, 18 transcriptionally altered (putative) transcriptional regulators were deleted, but none of the deletion strains showed noticeable growth kinetics under an oxygen restricted environment. However, the described transcriptional adaptation of C. glutamicum resolved to varying oxygen availabilities provides a useful basis for future process and strain engineering.
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Affiliation(s)
- Julian Lange
- Institute of Biochemical Engineering, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany.
| | - Eugenia Münch
- Institute of Biochemical Engineering, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany.
| | - Jan Müller
- Institute of Biochemical Engineering, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany.
| | - Tobias Busche
- Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615 Bielefeld, Germany.
- Institute for Biology-Microbiology, Freie Universität Berlin, Königin-Luise-Str. 12-16, 14195 Berlin, Germany.
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615 Bielefeld, Germany.
| | - Ralf Takors
- Institute of Biochemical Engineering, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany.
| | - Bastian Blombach
- Institute of Biochemical Engineering, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany.
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Dostálová H, Holátko J, Busche T, Rucká L, Rapoport A, Halada P, Nešvera J, Kalinowski J, Pátek M. Assignment of sigma factors of RNA polymerase to promoters in Corynebacterium glutamicum. AMB Express 2017. [PMID: 28651382 PMCID: PMC5483222 DOI: 10.1186/s13568-017-0436-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Corynebacterium glutamicum is an important industrial producer of various amino acids and other metabolites. The C. glutamicum genome encodes seven sigma subunits (factors) of RNA polymerase: the primary sigma factor SigA (σA), the primary-like σB and five alternative sigma factors (σC, σD, σE, σH and σM). We have developed in vitro and in vivo methods to assign particular sigma factors to individual promoters of different classes. In vitro transcription assays and measurements of promoter activity using the overexpression of a single sigma factor gene and the transcriptional fusion of the promoter to the gfpuv reporter gene enabled us to reliably define the sigma factor dependency of promoters. To document the strengths of these methods, we tested examples of respective promoters for each C. glutamicum sigma factor. Promoters of the rshA (anti-sigma for σH) and trxB1 (thioredoxin) genes were found to be σH-dependent, whereas the promoter of the sigB gene (sigma factor σB) was σE- and σH-dependent. It was confirmed that the promoter of the cg2556 gene (iron-regulated membrane protein) is σC-dependent as suggested recently by other authors. The promoter of cmt1 (trehalose corynemycolyl transferase) was found to be clearly σD-dependent. No σM-dependent promoter was identified. The typical housekeeping promoter P2sigA (sigma factor σA) was proven to be σA-dependent but also recognized by σB. Similarly, the promoter of fba (fructose-1,6-bisphosphate aldolase) was confirmed to be σB-dependent but also functional with σA. The study provided demonstrations of the broad applicability of the developed methods and produced original data on the analyzed promoters.
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10
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Yang SS, Hu YB, Wang XD, Gao YR, Li K, Zhang XE, Chen SY, Zhang TY, Gu J, Deng JY. Deletion of sigB Causes Increased Sensitivity to para-Aminosalicylic Acid and Sulfamethoxazole in Mycobacterium tuberculosis. Antimicrob Agents Chemother 2017; 61:e00551-17. [PMID: 28717039 PMCID: PMC5610497 DOI: 10.1128/aac.00551-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/09/2017] [Indexed: 12/18/2022] Open
Abstract
Although the de novo folate biosynthesis pathway has been well studied in bacteria, little is known about its regulation. In the present study, the sigB gene in Mycobacterium tuberculosis was deleted. Subsequent drug susceptibility tests revealed that the M. tuberculosis ΔsigB strain was more sensitive to para-aminosalicylic acid (PAS) and sulfamethoxazole. Comparative transcriptional analysis was performed, and downregulation of pabB was observed in the ΔsigB strain, which was further verified by a quantitative reverse transcription-PCR and Western blot assay. Then, the production levels of para-aminobenzoic acid (pABA) were compared between the sigB deletion mutant and wild-type strain, and the results showed that sigB deletion resulted in decreased production of pABA. In addition, SigB was able to recognize the promoter of pabB in vitro Furthermore, we found that deleting pabC also caused increased susceptibility to PAS. Taken together, our data revealed that, in M. tuberculosis, sigB affects susceptibility to antifolates through multiple ways, primarily by regulating the expression of pabB To our knowledge, this is the first report showing that SigB modulates pABA biosynthesis and thus affecting susceptibility to antifolates, which broadens our understanding of the regulation of bacterial folate metabolism and mechanisms of susceptibility to antifolates.
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Affiliation(s)
- Shan-Shan Yang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yang-Bo Hu
- Key Laboratory of Special Pathogens and Biosafety, Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Xu-De Wang
- School of Stomatology and Medicine, Foshan University, Foshan, China
| | - Yun-Rong Gao
- The Joint Center of Translational Precision Medicine, Guangzhou Institute of Pediatrics, Guangzhou Women and Children Medical Center, Guangzhou, China
| | - Kun Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Xian-En Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Shi-Yun Chen
- Key Laboratory of Special Pathogens and Biosafety, Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Tian-Yu Zhang
- University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Jing Gu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Jiao-Yu Deng
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- Guangdong Province Key Laboratory of TB Systems Biology and Translational Medicine, Foshan, China
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11
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Albersmeier A, Pfeifer-Sancar K, Rückert C, Kalinowski J. Genome-wide determination of transcription start sites reveals new insights into promoter structures in the actinomycete Corynebacterium glutamicum. J Biotechnol 2017; 257:99-109. [PMID: 28412515 DOI: 10.1016/j.jbiotec.2017.04.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 04/06/2017] [Accepted: 04/11/2017] [Indexed: 12/21/2022]
Abstract
The genome-wide identification of transcription start sites, enabled by high-throughput sequencing of a cDNA library enriched for native 5' transcript ends, is ideally suited for the analysis of promoters. Here, the transcriptome of Corynebacterium glutamicum, a non-pathogenic soil bacterium from the actinomycetes branch that is used in industry for the production of amino acids, was analysed by transcriptome sequencing of the 5'-ends of native transcripts. Total RNA samples were harvested from the exponential phase of growth, therefore the study mainly addressed promoters recognized by the main house-keeping sigma factor σA. The identification of 2454 transcription start sites (TSS) allowed the detailed analysis of most promoters recognized by σA and furthermore enabled us to form different promoter groups according to their location relative to protein-coding regions. These groups included leaderless transcripts (546 promoters), short-leadered (<500 bases) transcripts (917), and long-leadered (>500 bases) transcripts (173) as well as intragenic (557) and antisense transcripts (261). All promoters and the individual groups were searched for information, e.g. conserved residues and promoter motifs, and general design features as well as group-specific preferences were identified. A purine was found highly favored as TSS, whereas the -1 position was dominated by pyrimidines. The spacer between TSS and -10 region were consistently 6-7 bases and the -10 promoter motif was generally visible, whereas a recognizable -35 region was only occurring in a smaller fraction of promoters (7.5%) and enriched for leadered and antisense transcripts but depleted for leaderless transcripts. Promoters showing an extended -10 region were especially frequent in case of non-canonical -10 motifs (45.5%). Two bases downstream of the -10 core region, a G was conserved, exceeding 40% abundance in most groups. This fraction reached 74.6% for a group of putative σB-dependent promoters, thus giving a hint to a specific property of these promoters. In addition, the high number of promoters analysed allowed finding of subtle signals only showing up significantly with this large set. This included the observation of a periodically changing A+T-content with maxima spaced by a full turn of the DNA helix. This periodic structure includes the A+T-rich UP-element of bacterial promoters known before but was found to extend up to -100, indicating hitherto unknown constraints influencing promoter architecture and possibly also promoter function.
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Affiliation(s)
- Andreas Albersmeier
- Microbial Genomics Biotechnology, Centrum für Biotechnologie Universität Bielefeld, Sequenz 1, 33615 Bielefeld, Germany
| | - Katharina Pfeifer-Sancar
- Microbial Genomics Biotechnology, Centrum für Biotechnologie Universität Bielefeld, Sequenz 1, 33615 Bielefeld, Germany
| | - Christian Rückert
- Microbial Genomics Biotechnology, Centrum für Biotechnologie Universität Bielefeld, Sequenz 1, 33615 Bielefeld, Germany
| | - Jörn Kalinowski
- Microbial Genomics Biotechnology, Centrum für Biotechnologie Universität Bielefeld, Sequenz 1, 33615 Bielefeld, Germany.
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Enhanced Glucose Consumption and Organic Acid Production by Engineered Corynebacterium glutamicum Based on Analysis of a pfkB1 Deletion Mutant. Appl Environ Microbiol 2017; 83:AEM.02638-16. [PMID: 27881414 DOI: 10.1128/aem.02638-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 11/17/2016] [Indexed: 02/08/2023] Open
Abstract
In the analysis of a carbohydrate metabolite pathway, we found interesting phenotypes in a mutant strain of Corynebacterium glutamicum deficient in pfkB1, which encodes fructose-1-phosphate kinase. After being aerobically cultivated with fructose as a carbon source, this mutant consumed glucose and produced organic acid, predominantly l-lactate, at a level more than 2-fold higher than that of the wild-type grown with glucose under conditions of oxygen deprivation. This considerably higher fermentation capacity was unique for the combination of pfkB1 deletion and cultivation with fructose. In the metabolome and transcriptome analyses of this strain, marked intracellular accumulation of fructose-1-phosphate and significant upregulation of several genes related to the phosphoenolpyruvate:carbohydrate phosphotransferase system, glycolysis, and organic acid synthesis were identified. We then examined strains overexpressing several of the identified genes and demonstrated enhanced glucose consumption and organic acid production by these engineered strains, whose values were found to be comparable to those of the model pfkB1 deletion mutant grown with fructose. l-Lactate production by the ppc deletion mutant of the engineered strain was 2,390 mM (i.e., 215 g/liter) after 48 h under oxygen deprivation, which was a 2.7-fold increase over that of the wild-type strain with a deletion of ppc IMPORTANCE: Enhancement of glycolytic flux is important for improving microbiological production of chemicals, but overexpression of glycolytic enzymes has often resulted in little positive effect. That is presumably because the central carbon metabolism is under the complex and strict regulation not only transcriptionally but also posttranscriptionally, for example, by the ATP/ADP ratio. In contrast, we studied a mutant strain of Corynebacterium glutamicum that showed markedly enhanced glucose consumption and organic acid production and, based on the findings, identified several genes whose overexpression was effective in enhancing glycolytic flux under conditions of oxygen deprivation. These results will further understanding of the regulatory mechanisms of glycolytic flux and can be widely applied to the improvement of the microbial production of useful chemicals.
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Overexpression of the primary sigma factor gene sigA improved carotenoid production by Corynebacterium glutamicum: Application to production of β-carotene and the non-native linear C50 carotenoid bisanhydrobacterioruberin. Metab Eng Commun 2017; 4:1-11. [PMID: 29142827 PMCID: PMC5678898 DOI: 10.1016/j.meteno.2017.01.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 12/14/2016] [Accepted: 01/12/2017] [Indexed: 02/07/2023] Open
Abstract
Corynebacterium glutamicum shows yellow pigmentation due to biosynthesis of the C50 carotenoid decaprenoxanthin and its glycosides. This bacterium has been engineered for production of various non-native cyclic C40 and C50 carotenoids such as β-carotene, astaxanthin or sarcinaxanthin. In this study, the effect of modulating gene expression more broadly by overexpression of sigma factor genes on carotenoid production by C. glutamicum was characterized. Overexpression of the primary sigma factor gene sigA improved lycopene production by recombinant C. glutamicum up to 8-fold. In C. glutamicum wild type, overexpression of sigA led to 2-fold increased accumulation of the native carotenoid decaprenoxanthin in the stationary growth phase. Under these conditions, genes related to thiamine synthesis and aromatic compound degradation showed increased RNA levels and addition of thiamine and the aromatic iron chelator protocatechuic acid to the culture medium enhanced carotenoid production when sigA was overexpressed. Deletion of the gene for the alternative sigma factor SigB, which is expected to replace SigA in RNA polymerase holoenzymes during transition to the stationary growth phase, also increased carotenoid production. The strategy of sigA overexpression could be successfully transferred to production of the non-native carotenoids β-carotene and bisanhydrobacterioruberin (BABR). Production of the latter is the first demonstration that C. glutamicum may accumulate a non-native linear C50 carotenoid instead of the native cyclic C50 carotenoid decaprenoxanthin. Overexpression of the primary sigma factor gene sigA enhanced carotenoid production. Enhanced production of carotenoids in the absence of alternative sigma factor SigB. Production of the linear C50 carotenoid bisanhydrobacterioruberin established.
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14
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Sun Y, Guo W, Wang F, Peng F, Yang Y, Dai X, Liu X, Bai Z. Transcriptome and Multivariable Data Analysis of Corynebacterium glutamicum under Different Dissolved Oxygen Conditions in Bioreactors. PLoS One 2016; 11:e0167156. [PMID: 27907077 PMCID: PMC5132257 DOI: 10.1371/journal.pone.0167156] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 11/09/2016] [Indexed: 12/16/2022] Open
Abstract
Dissolved oxygen (DO) is an important factor in the fermentation process of Corynebacterium glutamicum, which is a widely used aerobic microbe in bio-industry. Herein, we described RNA-seq for C. glutamicum under different DO levels (50%, 30% and 0%) in 5 L bioreactors. Multivariate data analysis (MVDA) models were used to analyze the RNA-seq and metabolism data to investigate the global effect of DO on the transcriptional distinction of the substance and energy metabolism of C. glutamicum. The results showed that there were 39 and 236 differentially expressed genes (DEGs) under the 50% and 0% DO conditions, respectively, compared to the 30% DO condition. Key genes and pathways affected by DO were analyzed, and the result of the MVDA and RNA-seq revealed that different DO levels in the fermenter had large effects on the substance and energy metabolism and cellular redox balance of C. glutamicum. At low DO, the glycolysis pathway was up-regulated, and TCA was shunted by the up-regulation of the glyoxylate pathway and over-production of amino acids, including valine, cysteine and arginine. Due to the lack of electron-acceptor oxygen, 7 genes related to the electron transfer chain were changed, causing changes in the intracellular ATP content at 0% and 30% DO. The metabolic flux was changed to rebalance the cellular redox. This study applied deep sequencing to identify a wealth of genes and pathways that changed under different DO conditions and provided an overall comprehensive view of the metabolism of C. glutamicum. The results provide potential ways to improve the oxygen tolerance of C. glutamicum and to modify the metabolic flux for amino acid production and heterologous protein expression.
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Affiliation(s)
- Yang Sun
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Wenwen Guo
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Fen Wang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Feng Peng
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Yankun Yang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xiaofeng Dai
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xiuxia Liu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Zhonghu Bai
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
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Kogure T, Kubota T, Suda M, Hiraga K, Inui M. Metabolic engineering of Corynebacterium glutamicum for shikimate overproduction by growth-arrested cell reaction. Metab Eng 2016; 38:204-216. [DOI: 10.1016/j.ymben.2016.08.005] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/16/2016] [Accepted: 08/18/2016] [Indexed: 11/30/2022]
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16
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Pahlke J, Dostálová H, Holátko J, Degner U, Bott M, Pátek M, Polen T. The small 6C RNA of Corynebacterium glutamicum is involved in the SOS response. RNA Biol 2016; 13:848-60. [PMID: 27362471 PMCID: PMC5014011 DOI: 10.1080/15476286.2016.1205776] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The 6C RNA family is a class of small RNAs highly conserved in Actinobacteria, including the genera Mycobacterium, Streptomyces and Corynebacterium whose physiological function has not yet been elucidated. We found that strong transcription of the cgb_03605 gene, which encodes 6C RNA in C. glutamicum, was driven by the SigA- and SigB-dependent promoter Pcgb_03605. 6C RNA was detected at high level during exponential growth phase (180 to 240 molcules per cell) which even increased at the entry of the stationary phase. 6C RNA level did not decrease within 240 min after transcription had been stopped with rifampicin, which suggests high 6C RNA stability. The expression of cgb_03605 further increased approximately twofold in the presence of DNA-damaging mitomycin C (MMC) and nearly threefold in the absence of LexA. Deletion of the 6C RNA gene cgb_03605 resulted in a higher sensitivity of C. glutamicum toward MMC and UV radiation. These results indicate that 6C RNA is involved in the DNA damage response. Both 6C RNA level-dependent pausing of cell growth and branched cell morphology in response to MMC suggest that 6C RNA may also be involved in a control of cell division.
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Affiliation(s)
- Jennifer Pahlke
- a Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH , Jülich , Germany
| | - Hana Dostálová
- b Institute of Microbiology of the CAS , v. v. i. Videnska, Czech Republic
| | - Jiří Holátko
- b Institute of Microbiology of the CAS , v. v. i. Videnska, Czech Republic
| | - Ursula Degner
- a Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH , Jülich , Germany
| | - Michael Bott
- a Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH , Jülich , Germany
| | - Miroslav Pátek
- b Institute of Microbiology of the CAS , v. v. i. Videnska, Czech Republic
| | - Tino Polen
- a Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH , Jülich , Germany
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17
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Use of In Vitro Transcription System for Analysis of Corynebacterium glutamicum Promoters Recognized by Two Sigma Factors. Curr Microbiol 2016; 73:401-408. [DOI: 10.1007/s00284-016-1077-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 05/26/2016] [Indexed: 10/21/2022]
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18
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Toyoda K, Inui M. The extracytoplasmic function σ factor σ(C) regulates expression of a branched quinol oxidation pathway in Corynebacterium glutamicum. Mol Microbiol 2016; 100:486-509. [PMID: 26789738 DOI: 10.1111/mmi.13330] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2016] [Indexed: 11/30/2022]
Abstract
Bacteria modify their expression of different terminal oxidases in response to oxygen availability. Corynebacterium glutamicum, a facultative anaerobic bacterium of the phylum Actinobacteria, possesses aa3 -type cytochrome c oxidase and cytochrome bd-type quinol oxidase, the latter of which is induced by oxygen limitation. We report that an extracytoplasmic function σ factor, σ(C) , is responsible for the regulation of this process. Chromatin immunoprecipitation with microarray analysis detected eight σ(C) -binding regions in the genome, facilitating the identification of a consensus promoter sequence for σ(C) recognition. The promoter sequences were found upstream of genes for cytochrome bd, heme a synthesis enzymes and uncharacterized membrane proteins, all of which were upregulated by sigC overexpression. However, one consensus promoter sequence found on the antisense strand upstream of an operon encoding the cytochrome bc1 complex conferred a σ(C) -dependent negative effect on expression of the operon. The σ(C) regulon was induced by cytochrome aa3 deficiency without modifying sigC expression, but not by bc1 complex deficiency. These findings suggest that σ(C) is activated in response to impaired electron transfer via cytochrome aa3 and not directly to a shift in oxygen levels. Our results reveal a new paradigm for transcriptional regulation of the aerobic respiratory system in bacteria.
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Affiliation(s)
- Koichi Toyoda
- Research institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan
| | - Masayuki Inui
- Research institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.,Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara, 630-0101, Japan
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Development of a potential stationary-phase specific gene expression system by engineering of SigB-dependent cg3141 promoter in Corynebacterium glutamicum. Appl Microbiol Biotechnol 2016; 100:4473-83. [PMID: 26782746 DOI: 10.1007/s00253-016-7297-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 12/27/2015] [Accepted: 12/28/2015] [Indexed: 02/03/2023]
Abstract
Corynebacterium glutamicum is a non-pathogenic, non-sporulating Gram-positive soil bacterium that has been used for the industrial production of various proteins and chemicals. To achieve enhanced and economical production of target molecules, the development of strong auto-inducible promoters is desired, which can be activated without expensive inducers and has significant advantages for industrial-scale use. Here, we developed a stationary-phase gene expression system by engineering a sigma factor B (SigB)-dependent promoter that can be activated during the transition phase between exponential and stationary growth phases in C. glutamicum. First, the inducibilities of three well-known SigB-dependent promoters were examined using super-folder green fluorescent protein as a reporter protein, and we found that promoter of cg3141 (P cg3141 ) exhibited the highest inducibility. Next, a synthetic promoter library was constructed by randomizing the flanking and space regions of P cg3141 , and the stationary-phase promoters exhibiting high strengths were isolated via FACS-based high-throughput screening. The isolated synthetic promoter (P4-N14) showed a 3.5-fold inducibility and up to 20-fold higher strength compared to those of the original cg3141 promoter. Finally, the use of the isolated P4-N14 for fed-batch cultivation was verified with the production of glutathione S-transferase as a model protein in a lab-scale (5-L) bioreactor.
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Toyoda K, Inui M. Regulons of global transcription factors in Corynebacterium glutamicum. Appl Microbiol Biotechnol 2015; 100:45-60. [DOI: 10.1007/s00253-015-7074-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 10/03/2015] [Accepted: 10/07/2015] [Indexed: 10/22/2022]
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21
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Taniguchi H, Wendisch VF. Exploring the role of sigma factor gene expression on production by Corynebacterium glutamicum: sigma factor H and FMN as example. Front Microbiol 2015; 6:740. [PMID: 26257719 PMCID: PMC4510997 DOI: 10.3389/fmicb.2015.00740] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 07/06/2015] [Indexed: 12/25/2022] Open
Abstract
Bacteria are known to cope with environmental changes by using alternative sigma factors binding to RNA polymerase core enzyme. Sigma factor is one of the targets to modify transcription regulation in bacteria and to influence production capacities. In this study, the effect of overexpressing each annotated sigma factor gene in Corynebacterium glutamicum WT was assayed using an IPTG inducible plasmid system and different IPTG concentrations. It was revealed that growth was severely decreased when sigD or sigH were overexpressed with IPTG concentrations higher than 50 μM. Overexpression of sigH led to an obvious phenotypic change, a yellow-colored supernatant. High performance liquid chromatography analysis revealed that riboflavin was excreted to the medium when sigH was overexpressed and DNA microarray analysis confirmed increased expression of riboflavin biosynthesis genes. In addition, genes for enzymes related to the pentose phosphate pathway and for enzymes dependent on flavin mononucleotide (FMN), flavin adenine dinucleotide (FAD), or NADPH as cofactor were upregulated when sigH was overexpressed. To test if sigH overexpression can be exploited for production of riboflavin-derived FMN or FAD, the endogenous gene for bifunctional riboflavin kinase/FMN adenyltransferase was co-expressed with sigH from a plasmid. Balanced expression of sigH and ribF improved accumulation of riboflavin (19.8 ± 0.3 μM) and allowed for its conversion to FMN (33.1 ± 1.8 μM) in the supernatant. While a proof-of-concept was reached, conversion was not complete and titers were not high. This study revealed that inducible and gradable overexpression of sigma factor genes is an interesting approach to switch gene expression profiles and to discover untapped potential of bacteria for chemical production.
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Affiliation(s)
- Hironori Taniguchi
- Genetics of Prokaryotes, Faculty of Biology and Center for Biotechnology, Bielefeld University Bielefeld, Germany
| | - Volker F Wendisch
- Genetics of Prokaryotes, Faculty of Biology and Center for Biotechnology, Bielefeld University Bielefeld, Germany
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22
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Nešvera J, Holátko J, Pátek M. Analysis of Corynebacterium glutamicum promoters and their applications. Subcell Biochem 2014; 64:203-21. [PMID: 23080252 DOI: 10.1007/978-94-007-5055-5_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Promoters are DNA sequences which function as regulatory signals of transcription initiation catalyzed by RNA polymerase. Since promoters substantially influence levels of gene expression, they have become powerful tools in metabolic engineering. Methods for their localization used in Corynebacterium glutamicum and techniques for the analysis of their function are described in this review. C. glutamicum promoters can be classified according to the respective σ factors which direct RNA polymerase to these structures. C. glutamicum promoters are recognized by holo-RNA polymerase formed by subunits α(2)ββ'ω + σ. C. glutamicum codes for seven different sigma factors: the principal sigma factor σ(A) and alternative sigma factors σ(B), σ(C), σ(D), σ(E), σ(H) and σ(M), which recognize various classes of promoters. The promoters of housekeeping genes recognized by σ(A), which are active during the exponential growth, form the largest described group. These promoters and their mutant derivatives are the most frequently used elements in modulation of gene expression in C. glutamicum. Promoters recognized by alternative sigma factors and their consensus sequences are gradually emerging.
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Affiliation(s)
- Jan Nešvera
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, CZ-14220, Prague 4, Czech Republic
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Khuat HBT, Kaboré AK, Olmos E, Fick M, Boudrant J, Goergen JL, Delaunay S, Guedon E. Lactate production as representative of the fermentation potential of Corynebacterium glutamicum 2262 in a one-step process. Biosci Biotechnol Biochem 2014; 78:343-9. [PMID: 25036691 DOI: 10.1080/09168451.2014.878219] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The fermentative properties of thermo-sensitive strain Corynebacterium glutamicum 2262 were investigated in processes coupling aerobic cell growth and the anaerobic fermentation phase. In particular, the influence of two modes of fermentation on the production of lactate, the fermentation product model, was studied. In both processes, lactate was produced in significant amount, 27 g/L in batch culture, and up to 55.8 g/L in fed-batch culture, but the specific production rate in the fed-batch culture was four times lower than that in the batch culture. Compared to other investigated fermentation processes, our strategy resulted in the highest yield of lactic acid from biomass. Lactate production by C. glutamicum 2262 thus revealed the capability of the strain to produce various fermentation products from pyruvate.
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Affiliation(s)
- Hoang Bao Truc Khuat
- a Laboratoire Réactions et Génie des Procédés , UMR CNRS 7274, ENSAIA - Université de Lorraine , Vandoeuvre Cedex , France
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Hasegawa S, Suda M, Uematsu K, Natsuma Y, Hiraga K, Jojima T, Inui M, Yukawa H. Engineering of Corynebacterium glutamicum for high-yield L-valine production under oxygen deprivation conditions. Appl Environ Microbiol 2013. [PMID: 23241971 DOI: 10.1128/aεm.02806-12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023] Open
Abstract
We previously demonstrated efficient L-valine production by metabolically engineered Corynebacterium glutamicum under oxygen deprivation. To achieve the high productivity, a NADH/NADPH cofactor imbalance during the synthesis of l-valine was overcome by engineering NAD-preferring mutant acetohydroxy acid isomeroreductase (AHAIR) and using NAD-specific leucine dehydrogenase from Lysinibacillus sphaericus. Lactate as a by-product was largely eliminated by disrupting the lactate dehydrogenase gene ldhA. Nonetheless, a few other by-products, particularly succinate, were still produced and acted to suppress the L-valine yield. Eliminating these by-products therefore was deemed key to improving theL-valine yield. By additionally disrupting the phosphoenolpyruvate carboxylase gene ppc, succinate production was effectively suppressed, but both glucose consumption and L-valine production dropped considerably due to the severely elevated intracellular NADH/NAD(+) ratio. In contrast, this perturbed intracellular redox state was more than compensated for by deletion of three genes associated with NADH-producing acetate synthesis and overexpression of five glycolytic genes, including gapA, encoding NADH-inhibited glyceraldehyde-3-phosphate dehydrogenase. Inserting feedback-resistant mutant acetohydroxy acid synthase and NAD-preferring mutant AHAIR in the chromosome resulted in higher L-valine yield and productivity. Deleting the alanine transaminase gene avtA suppressed alanine production. The resultant strain produced 1,280 mM L-valine at a yield of 88% mol mol of glucose(-1) after 24 h under oxygen deprivation, a vastly improved yield over our previous best.
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Affiliation(s)
- Satoshi Hasegawa
- Research Institute of Innovative Technology for the Earth, Kizugawadai, Kizugawa, Kyoto, Japan
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Pátek M, Holátko J, Busche T, Kalinowski J, Nešvera J. Corynebacterium glutamicum promoters: a practical approach. Microb Biotechnol 2013; 6:103-17. [PMID: 23305350 PMCID: PMC3917453 DOI: 10.1111/1751-7915.12019] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 11/05/2012] [Accepted: 11/08/2012] [Indexed: 11/27/2022] Open
Abstract
Transcription initiation is the key step in gene expression in bacteria, and it is therefore studied for both theoretical and practical reasons. Promoters, the traffic lights of transcription initiation, are used as construction elements in biotechnological efforts to coordinate ‘green waves’ in the metabolic pathways leading to the desired metabolites. Detailed analyses of Corynebacterium glutamicum promoters have already provided large amounts of data on their structures, regulatory mechanisms and practical capabilities in metabolic engineering. In this minireview the main aspects of promoter studies, the methods developed for their analysis and their practical use in C. glutamicum are discussed. These include definitions of the consensus sequences of the distinct promoter classes, promoter localization and characterization, activity measurements, the functions of transcriptional regulators and examples of practical uses of constitutive, inducible and modified promoters in biotechnology. The implications of the introduction of novel techniques, such as in vitro transcription and RNA sequencing, to C. glutamicum promoter studies are outlined.
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Affiliation(s)
- Miroslav Pátek
- Institute of Microbiology AS CR, vvi, Prague 4, Czech Republic.
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Barriuso-Iglesias M, Barreiro C, Sola-Landa A, Martín JF. Transcriptional control of the F0F1-ATP synthase operon of Corynebacterium glutamicum: SigmaH factor binds to its promoter and regulates its expression at different pH values. Microb Biotechnol 2013; 6:178-88. [PMID: 23298179 PMCID: PMC3917460 DOI: 10.1111/1751-7915.12022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 11/03/2012] [Indexed: 12/05/2022] Open
Abstract
Corynebacterium glutamicum used in the amino acid fermentation industries is an alkaliphilic microorganism. Its F0F1-ATPase operon (atpBEFHAGDC) is expressed optimally at pH 9.0 forming a polycistronic (7.5 kb) and a monocistronic (1.2 kb) transcripts both starting upstream of the atpB gene. Expression of this operon is controlled by the SigmaH factor. The sigmaH gene (sigH) was cloned and shown to be co-transcribed with a small gene, cg0877, encoding a putative anti-sigma factor. A mutant deleted in the sigH gene expressed the atpBEFHAGDC operon optimally at pH 7.0 at difference of the wild-type strain (optimal expression at pH 9.0). These results suggested that the SigmaH factor is involved in pH control of expression of the F0F1 ATPase operon. The SigmaH protein was expressed in Escherichia coli fused to the GST (glutathione-S-transferase) and purified to homogeneity by affinity chromatography on a GSTrap HP column. The fused protein was identified by immunodetection with anti-GST antibodies. DNA-binding studies by electrophoretic mobility shift assays showed that the SigH protein binds to a region of the atpB promoter containing the sigmaH recognition sequence (−35)TTGGAT…18nt…GTTA(−10). SigmaH plays an important role in the cascade of control of pH stress in Corynebacterium.
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Pátek M, Nešvera J. Promoters and Plasmid Vectors of Corynebacterium glutamicum. CORYNEBACTERIUM GLUTAMICUM 2013. [DOI: 10.1007/978-3-642-29857-8_2] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Teramoto H, Inui M. Regulation of Sugar Uptake, Glycolysis, and the Pentose Phosphate Pathway in Corynebacterium glutamicum. CORYNEBACTERIUM GLUTAMICUM 2013. [DOI: 10.1007/978-3-642-29857-8_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Engineering of Corynebacterium glutamicum for high-yield L-valine production under oxygen deprivation conditions. Appl Environ Microbiol 2012; 79:1250-7. [PMID: 23241971 DOI: 10.1128/aem.02806-12] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously demonstrated efficient L-valine production by metabolically engineered Corynebacterium glutamicum under oxygen deprivation. To achieve the high productivity, a NADH/NADPH cofactor imbalance during the synthesis of l-valine was overcome by engineering NAD-preferring mutant acetohydroxy acid isomeroreductase (AHAIR) and using NAD-specific leucine dehydrogenase from Lysinibacillus sphaericus. Lactate as a by-product was largely eliminated by disrupting the lactate dehydrogenase gene ldhA. Nonetheless, a few other by-products, particularly succinate, were still produced and acted to suppress the L-valine yield. Eliminating these by-products therefore was deemed key to improving theL-valine yield. By additionally disrupting the phosphoenolpyruvate carboxylase gene ppc, succinate production was effectively suppressed, but both glucose consumption and L-valine production dropped considerably due to the severely elevated intracellular NADH/NAD(+) ratio. In contrast, this perturbed intracellular redox state was more than compensated for by deletion of three genes associated with NADH-producing acetate synthesis and overexpression of five glycolytic genes, including gapA, encoding NADH-inhibited glyceraldehyde-3-phosphate dehydrogenase. Inserting feedback-resistant mutant acetohydroxy acid synthase and NAD-preferring mutant AHAIR in the chromosome resulted in higher L-valine yield and productivity. Deleting the alanine transaminase gene avtA suppressed alanine production. The resultant strain produced 1,280 mM L-valine at a yield of 88% mol mol of glucose(-1) after 24 h under oxygen deprivation, a vastly improved yield over our previous best.
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Abstract
The non-essential Corynebacterium glutamicum sigma factor, sigB, modulates global gene expression during the transition from exponential growth to the stationary phase. Utilizing a signal peptide derived from C. glutamicum R CgR_0949, a sigB disruption mutant able to secrete 3- to 5-fold more green fluorescence protein (GFP) and α-amylase than the wild type strain was isolated. The signal peptide selectively enabled the mutant to produce greater amounts of both proteins, which were in turn secreted in culture medium in greater quantities than previously acknowledged. A peak GFP productivity of 2.8 g/l was attained, representing the highest GFP productivity reported in C. glutamicum to date. CgR_0949 signal sequence length (30 residues), type (Tat) or the target protein identity (GFP or α-amylase) had no measurable effect on the magnitude of the protein accumulation and consequent secretion. It therefore follows that actual experimentation remains the fastest way to identify suitable signal sequences in C. glutamicum. More secretion studies may reveal even greater secretion productivity by C. glutamicum and consequently present an attractive avenue to further enhance the utility of C. glutamicum as an industrial workhorse.
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Busche T, Silar R, Pičmanová M, Pátek M, Kalinowski J. Transcriptional regulation of the operon encoding stress-responsive ECF sigma factor SigH and its anti-sigma factor RshA, and control of its regulatory network in Corynebacterium glutamicum. BMC Genomics 2012; 13:445. [PMID: 22943411 PMCID: PMC3489674 DOI: 10.1186/1471-2164-13-445] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 08/22/2012] [Indexed: 02/02/2023] Open
Abstract
Background The expression of genes in Corynebacterium glutamicum, a Gram-positive non-pathogenic bacterium used mainly for the industrial production of amino acids, is regulated by seven different sigma factors of RNA polymerase, including the stress-responsive ECF-sigma factor SigH. The sigH gene is located in a gene cluster together with the rshA gene, putatively encoding an anti-sigma factor. The aim of this study was to analyze the transcriptional regulation of the sigH and rshA gene cluster and the effects of RshA on the SigH regulon, in order to refine the model describing the role of SigH and RshA during stress response. Results Transcription analyses revealed that the sigH gene and rshA gene are cotranscribed from four sigH housekeeping promoters in C. glutamicum. In addition, a SigH-controlled rshA promoter was found to only drive the transcription of the rshA gene. To test the role of the putative anti-sigma factor gene rshA under normal growth conditions, a C. glutamicum rshA deletion strain was constructed and used for genome-wide transcription profiling with DNA microarrays. In total, 83 genes organized in 61 putative transcriptional units, including those previously detected using sigH mutant strains, exhibited increased transcript levels in the rshA deletion mutant compared to its parental strain. The genes encoding proteins related to disulphide stress response, heat stress proteins, components of the SOS-response to DNA damage and proteasome components were the most markedly upregulated gene groups. Altogether six SigH-dependent promoters upstream of the identified genes were determined by primer extension and a refined consensus promoter consisting of 45 original promoter sequences was constructed. Conclusions The rshA gene codes for an anti-sigma factor controlling the function of the stress-responsive sigma factor SigH in C. glutamicum. Transcription of rshA from a SigH-dependent promoter may serve to quickly shutdown the SigH-dependent stress response after the cells have overcome the stress condition. Here we propose a model of the regulation of oxidative and heat stress response including redox homeostasis by SigH, RshA and the thioredoxin system.
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Affiliation(s)
- Tobias Busche
- Centrum für Biotechnologie, Universität Bielefeld, 33594, Bielefeld, Germany
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Holátko J, Šilar R, Rabatinová A, Šanderová H, Halada P, Nešvera J, Krásný L, Pátek M. Construction of in vitro transcription system for Corynebacterium glutamicum and its use in the recognition of promoters of different classes. Appl Microbiol Biotechnol 2012; 96:521-9. [DOI: 10.1007/s00253-012-4336-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 07/19/2012] [Accepted: 07/21/2012] [Indexed: 11/24/2022]
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Overexpression of genes encoding glycolytic enzymes in Corynebacterium glutamicum enhances glucose metabolism and alanine production under oxygen deprivation conditions. Appl Environ Microbiol 2012; 78:4447-57. [PMID: 22504802 DOI: 10.1128/aem.07998-11] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously reported that Corynebacterium glutamicum strain ΔldhAΔppc+alaD+gapA, overexpressing glyceraldehyde-3-phosphate dehydrogenase-encoding gapA, shows significantly improved glucose consumption and alanine formation under oxygen deprivation conditions (T. Jojima, M. Fujii, E. Mori, M. Inui, and H. Yukawa, Appl. Microbiol. Biotechnol. 87:159-165, 2010). In this study, we employ stepwise overexpression and chromosomal integration of a total of four genes encoding glycolytic enzymes (herein referred to as glycolytic genes) to demonstrate further successive improvements in C. glutamicum glucose metabolism under oxygen deprivation. In addition to gapA, overexpressing pyruvate kinase-encoding pyk and phosphofructokinase-encoding pfk enabled strain GLY2/pCRD500 to realize respective 13% and 20% improved rates of glucose consumption and alanine formation compared to GLY1/pCRD500. Subsequent overexpression of glucose-6-phosphate isomerase-encoding gpi in strain GLY3/pCRD500 further improved its glucose metabolism. Notably, both alanine productivity and yield increased after each overexpression step. After 48 h of incubation, GLY3/pCRD500 produced 2,430 mM alanine at a yield of 91.8%. This was 6.4-fold higher productivity than that of the wild-type strain. Intracellular metabolite analysis showed that gapA overexpression led to a decreased concentration of metabolites upstream of glyceraldehyde-3-phosphate dehydrogenase, suggesting that the overexpression resolved a bottleneck in glycolysis. Changing ratios of the extracellular metabolites by overexpression of glycolytic genes resulted in reduction of the intracellular NADH/NAD(+) ratio, which also plays an important role on the improvement of glucose consumption. Enhanced alanine dehydrogenase activity using a high-copy-number plasmid further accelerated the overall alanine productivity. Increase in glycolytic enzyme activities is a promising approach to make drastic progress in growth-arrested bioprocesses.
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Cho S, Yang S, Rhie H. The gene encoding the alternative thymidylate synthase ThyX is regulated by sigma factor SigB in Corynebacterium glutamicum ATCC 13032. FEMS Microbiol Lett 2012; 328:157-65. [PMID: 22224900 DOI: 10.1111/j.1574-6968.2011.02494.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 12/14/2011] [Accepted: 12/20/2011] [Indexed: 11/27/2022] Open
Abstract
Both ThyA and ThyX proteins catalyze the transfer of the methyl group from methylenetetrahydrofolate (CH(2) H(4) -folate) to dUMP, forming dTMP. To estimate the relative steady state expression levels of ThyA and ThyX, Western blot analysis was performed using ThyA or ThyX antiserum on total protein from the wild-type, ΔthyX, and thyX-complemented strains of Corynebacterium glutamicum. The level of ThyA decreased gradually during the stationary growth phase but that of ThyX was maintained steadily. Whereas the expression level of ThyA in a ΔsigB strain was comparable to that of the wild-type, the level of ThyX was significantly diminished in the deletion mutant and was restored to that of the wild-type in the complemented strain, indicating that the level of ThyX was regulated by SigB. Growth of the C. glutamicum ΔsigB strain was dependent upon coupling activity of dihydrofolate reductase (DHFR) with ThyA for the synthesis of thymidine, and thus showed sensitivity to the inhibition of DHFR by the experimental inhibitor, WR99210-HCl. These results suggested that the relative levels of ThyA and ThyX differ in response to different growth phases and that SigB is necessary for maintenance of the level of ThyX during transition into the stationary growth phase.
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Affiliation(s)
- Sukhyeong Cho
- Department of Biology, Kyung Hee University, Seoul, Korea
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Improvement of the redox balance increases L-valine production by Corynebacterium glutamicum under oxygen deprivation conditions. Appl Environ Microbiol 2011; 78:865-75. [PMID: 22138982 DOI: 10.1128/aem.07056-11] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Production of L-valine under oxygen deprivation conditions by Corynebacterium glutamicum lacking the lactate dehydrogenase gene ldhA and overexpressing the L-valine biosynthesis genes ilvBNCDE was repressed. This was attributed to imbalanced cofactor production and consumption in the overall L-valine synthesis pathway: two moles of NADH was generated and two moles of NADPH was consumed per mole of L-valine produced from one mole of glucose. In order to solve this cofactor imbalance, the coenzyme requirement for L-valine synthesis was converted from NADPH to NADH via modification of acetohydroxy acid isomeroreductase encoded by ilvC and introduction of Lysinibacillus sphaericus leucine dehydrogenase in place of endogenous transaminase B, encoded by ilvE. The intracellular NADH/NAD(+) ratio significantly decreased, and glucose consumption and L-valine production drastically improved. Moreover, L-valine yield increased and succinate formation decreased concomitantly with the decreased intracellular redox state. These observations suggest that the intracellular NADH/NAD(+) ratio, i.e., reoxidation of NADH, is the primary rate-limiting factor for L-valine production under oxygen deprivation conditions. The L-valine productivity and yield were even better and by-products derived from pyruvate further decreased as a result of a feedback resistance-inducing mutation in the acetohydroxy acid synthase encoded by ilvBN. The resultant strain produced 1,470 mM L-valine after 24 h with a yield of 0.63 mol mol of glucose(-1), and the L-valine productivity reached 1,940 mM after 48 h.
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Sigma factors and promoters in Corynebacterium glutamicum. J Biotechnol 2011; 154:101-13. [DOI: 10.1016/j.jbiotec.2011.01.017] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 01/05/2011] [Accepted: 01/18/2011] [Indexed: 11/19/2022]
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Park M, Cho S, Lee H, Sibley CH, Rhie H. Alternative thymidylate synthase, ThyX, involved in Corynebacterium glutamicum ATCC 13032 survival during stationary growth phase. FEMS Microbiol Lett 2010; 307:128-34. [PMID: 20636973 DOI: 10.1111/j.1574-6968.2010.01971.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
A BLASTP search has shown the presence of a gene homologous to an alternative thymidylate synthase (TS), thyX, in Corynebacterium glutamicum ATCC 13032. To determine if thyX is functionally analogous to thyA, thyX was cloned in a plasmid and the resulting construct was transferred by transformation into a thyA mutant of Escherichia coli. The ThyX from C. glutamicum compensated for the defect in TS-deficient E. coli. A functional knockout of the thyX gene was constructed by allelic replacement using a sucrose counter-selectable suicide plasmid and confirmed by PCR and reverse transcriptase-PCR analyses. This mutant was viable without thymidine supplementation, suggesting that thyX is not an essential gene in C. glutamicum. Growth of the thyX mutant was dependent upon coupling activity of dihydrofolate reductase (DHFR) with ThyA for the synthesis of thymidine, and thus showed sensitivity to the inhibition of DHFR by the experimental inhibitor, WR99210. This indicates that thymidine synthesis was at least partially dependent on thyX expression. As it approached stationary phase, the thyX mutant lost viability much more rapidly than the parental wild type and the mutant complemented the thyX gene, suggesting that the activity of the ThyX enzyme is important in that phase of the growth cycle.
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Affiliation(s)
- Mijeong Park
- Department of Biology, Kyung Hee University, Seoul, Korea
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Teramoto H, Inui M, Yukawa H. Regulation of genes involved in sugar uptake, glycolysis and lactate production in Corynebacterium glutamicum. Future Microbiol 2010; 5:1475-81. [DOI: 10.2217/fmb.10.114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Corynebacterium glutamicum is a nonpathogenic, GC-rich, Gram-positive bacterium with a long history in the industrial production of amino acids. Recently, the species has become of increasing interest as a model bacterium for closely related, medically important pathogenic species such as Corynebacterium diphtheriae and Mycobacterium tuberculosis. In this article, recent advances in understanding of the C. glutamicum regulatory network of genes involved in carbohydrate metabolism are reviewed with regards to sugar uptake, glycolysis and lactate production.
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Affiliation(s)
- Haruhiko Teramoto
- Research Institute of Innovative Technology for the Earth, 9–2, Kizugawadai, Kizugawa, Kyoto 619–0292, Japan
| | - Masayuki Inui
- Research Institute of Innovative Technology for the Earth, 9–2, Kizugawadai, Kizugawa, Kyoto 619–0292, Japan
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Schröder J, Tauch A. Transcriptional regulation of gene expression inCorynebacterium glutamicum: the role of global, master and local regulators in the modular and hierarchical gene regulatory network. FEMS Microbiol Rev 2010; 34:685-737. [DOI: 10.1111/j.1574-6976.2010.00228.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Engineering of sugar metabolism of Corynebacterium glutamicum for production of amino acid L-alanine under oxygen deprivation. Appl Microbiol Biotechnol 2010; 87:159-65. [PMID: 20217078 DOI: 10.1007/s00253-010-2493-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 02/01/2010] [Accepted: 02/02/2010] [Indexed: 10/19/2022]
Abstract
Corynebacterium glutamicum was genetically engineered to produce L-alanine from sugar under oxygen deprivation. The genes associated with production of organic acids in C. glutamicum were inactivated and the alanine dehydrogenase gene (alaD) from Lysinibacillus sphaericus was overexpressed to direct carbon flux from organic acids to alanine. Although the alaD-expressing strain produced alanine from glucose under oxygen deprivation, its productivity was relatively low due to retarded glucose consumption. Homologous overexpression of the gapA gene encoding glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in the alaD-expressing strain stimulated glucose consumption and consequently improved alanine productivity. In contrast gapA overexpression did not affect glucose consumption under aerobic conditions, indicating that oxygen deprivation engendered inefficient regeneration of NAD+ resulting in impaired GAPDH activity and reduced glucose consumption in the alanine-producing strains. Inactivation of the alanine racemase gene allowed production of L-alanine with optical purity greater than 99.5%. The resulting strain produced 98 g l(-1) of L-alanine after 32 h in mineral salts medium. Our results show promise for amino acid production under oxygen deprivation.
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Ehira S, Teramoto H, Inui M, Yukawa H. A novel redox-sensing transcriptional regulator CyeR controls expression of an Old Yellow Enzyme family protein in Corynebacterium glutamicum. MICROBIOLOGY-SGM 2010; 156:1335-1341. [PMID: 20110293 DOI: 10.1099/mic.0.036913-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Corynebacterium glutamicum cgR_2930 (cyeR) encodes a transcriptional regulator of the ArsR family. Its gene product, CyeR, was shown here to repress the expression of cyeR and the cgR_2931 (cye1)-cgR_2932 operon, which is located upstream of cyeR in the opposite orientation. The cye1 gene encodes an Old Yellow Enzyme family protein, members of which have been implicated in the oxidative stress response. CyeR binds to the intergenic region between cyeR and cye1. Expression of cyeR and cye1 is induced by oxidative stress, and the DNA-binding activity of CyeR is impaired by oxidants such as diamide and H(2)O(2). CyeR contains two cysteine residues, Cys-36 and Cys-43. Whereas mutation of the former (C36A) has no effect on the redox regulation of CyeR activity, mutating the latter (C43A, C43S) abolishes the DNA-binding activity of CyeR. Cys-43 of CyeR and its C36A derivative are modified upon treatment with diamide, suggesting an important role for Cys-43 in the redox regulation of CyeR activity. It is concluded that CyeR is a redox-sensing transcriptional regulator that controls cye1 expression.
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Affiliation(s)
- Shigeki Ehira
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Haruhiko Teramoto
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Masayuki Inui
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Hideaki Yukawa
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
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Functional genomics of pH homeostasis in Corynebacterium glutamicum revealed novel links between pH response, oxidative stress, iron homeostasis and methionine synthesis. BMC Genomics 2009; 10:621. [PMID: 20025733 PMCID: PMC2807442 DOI: 10.1186/1471-2164-10-621] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Accepted: 12/21/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The maintenance of internal pH in bacterial cells is challenged by natural stress conditions, during host infection or in biotechnological production processes. Comprehensive transcriptomic and proteomic analyses has been conducted in several bacterial model systems, yet questions remain as to the mechanisms of pH homeostasis. RESULTS Here we present the comprehensive analysis of pH homeostasis in C. glutamicum, a bacterium of industrial importance. At pH values between 6 and 9 effective maintenance of the internal pH at 7.5 +/- 0.5 pH units was found. By DNA microarray analyses differential mRNA patterns were identified. The expression profiles were validated and extended by 1D-LC-ESI-MS/MS based quantification of soluble and membrane proteins. Regulators involved were identified and thereby participation of numerous signaling modules in pH response was found. The functional analysis revealed for the first time the occurrence of oxidative stress in C. glutamicum cells at neutral and low pH conditions accompanied by activation of the iron starvation response. Intracellular metabolite pool analysis unraveled inhibition of the TCA and other pathways at low pH. Methionine and cysteine synthesis were found to be activated via the McbR regulator, cysteine accumulation was observed and addition of cysteine was shown to be toxic under acidic conditions. CONCLUSIONS Novel limitations for C. glutamicum at non-optimal pH values were identified by a comprehensive analysis on the level of the transcriptome, proteome, and metabolome indicating a functional link between pH acclimatization, oxidative stress, iron homeostasis, and metabolic alterations. The results offer new insights into bacterial stress physiology and new starting points for bacterial strain design or pathogen defense.
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Hänßler E, Müller T, Palumbo K, Patek M, Brocker M, Krämer R, Burkovski A. A game with many players: Control of gdh transcription in Corynebacterium glutamicum. J Biotechnol 2009; 142:114-22. [DOI: 10.1016/j.jbiotec.2009.04.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 04/09/2009] [Accepted: 04/20/2009] [Indexed: 11/25/2022]
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Ehira S, Teramoto H, Inui M, Yukawa H. Regulation of Corynebacterium glutamicum heat shock response by the extracytoplasmic-function sigma factor SigH and transcriptional regulators HspR and HrcA. J Bacteriol 2009; 191:2964-72. [PMID: 19270092 PMCID: PMC2681815 DOI: 10.1128/jb.00112-09] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Accepted: 02/24/2009] [Indexed: 11/20/2022] Open
Abstract
Heat shock response in Corynebacterium glutamicum was characterized by whole-genome expression analysis using a DNA microarray. It was indicated that heat shock response of C. glutamicum included not only upregulation of heat shock protein (HSP) genes encoding molecular chaperones and ATP-dependent proteases, but it also increased and decreased expression of more than 300 genes related to disparate physiological functions. An extracytoplasmic-function sigma factor, SigH, was upregulated by heat shock. The SigH regulon was defined by gene expression profiling using sigH-disrupted and overexpressing strains in conjunction with mapping of transcription initiation sites. A total of 45 genes, including HSP genes and genes involved in oxidative stress response, were identified as the SigH regulon. Expression of some HSP genes was also upregulated by deletion of the transcriptional regulators HspR and HrcA. HspR represses expression of the clpB and dnaK operons, and HrcA represses expression of groESL1 and groEL2. SigH was shown to play an important role in regulation of heat shock response in concert with HspR and HrcA, but its role is likely restricted to only a part of the regulation of C. glutamicum heat shock response. Upregulation of 18 genes encoding transcriptional regulators by heat shock suggests a complex regulatory network of heat shock response in C. glutamicum.
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Affiliation(s)
- Shigeki Ehira
- Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
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Ehira S, Ogino H, Teramoto H, Inui M, Yukawa H. Regulation of quinone oxidoreductase by the redox-sensing transcriptional regulator QorR in Corynebacterium glutamicum. J Biol Chem 2009; 284:16736-16742. [PMID: 19403527 DOI: 10.1074/jbc.m109.009027] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Corynebacterium glutamicum cgR_1435 (cg1552) encodes a protein of the DUF24 protein family, which is a novel family of transcriptional regulators. CgR1435 (QorR) is a negative regulator of cgR_1436 (qor2), which is located upstream of cgR_1435 (qorR) in the opposite orientation, and its structural gene. QorR binds to the intergenic region between qor2 and qorR to repress their expression, which is induced by the thiol-specific oxidant diamide. The DNA-binding activity of QorR is impaired by oxidants such as diamide, H(2)O(2), and cumene hydroperoxide in vitro, and its lone cysteine residue (Cys-17) is essential for redox-responsive regulation of QorR activity both in vivo and in vitro. Moreover, a disruptant of qor2, which is a homologue of the ytfG gene of Escherichia coli encoding quinone oxidoreductase, shows increased sensitivity to diamide. It is concluded that the redox-sensing transcriptional regulator QorR is involved in disulfide stress response of C. glutamicum by regulating qor2 expression.
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Affiliation(s)
- Shigeki Ehira
- From the Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Hidetaka Ogino
- From the Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Haruhiko Teramoto
- From the Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Masayuki Inui
- From the Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Hideaki Yukawa
- From the Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan.
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