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Gao Y, Zhang X, Xu G, Zhang X, Li H, Shi J, Xu Z. Enhanced L-serine production by Corynebacterium glutamicum based on novel insights into L-serine exporters. Biotechnol J 2024; 19:e2300136. [PMID: 37971189 DOI: 10.1002/biot.202300136] [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: 03/25/2023] [Revised: 10/11/2023] [Accepted: 11/13/2023] [Indexed: 11/19/2023]
Abstract
The L-serine exporters ThrE and SerE play important roles in L-serine production by Corynebacterium glutamicum. Deletion of both thrE and serE decreased L-serine titer by 60%, suggesting the existence of other L-serine exporters. A comparative transcriptomics identified NCgl0254 and NCgl0255 as novel L-serine exporters. Further analysis of the contributions of ThrE, SerE, NCgl0254, and NCgl0255 found that SerE was the major L-serine exporter in C. glutamicum and these four L-serine exporters were responsible for 79.7% of L-serine export. Deletion of one L-serine exporter upregulated the transcription levels of the other three, which might be coursed by increased intracellular concentrations of L-serine. Overexpression of NCgl0254 and NCgl0255 increased L-serine titer by 20.8% in C. glutamicum A36, while overexpression of the four L-serine exporters increased L-serine production by 31.9% (41.1 g·L-1 ) in C. glutamicum A36. The identification of novel L-serine exporters in C. glutamicum will help to improve industrial production of L-serine.
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Affiliation(s)
- Yujie Gao
- Biotechnology of Ministry of Education, Jiangnan University, Wuxi, China
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
| | - Xiaomei Zhang
- Laboratory of Pharmaceutical Engineering, School of Life Science and Health Engineering, Jiangnan University, Wuxi, China
| | - Guoqiang Xu
- Biotechnology of Ministry of Education, Jiangnan University, Wuxi, China
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
| | - Xiaojuan Zhang
- Biotechnology of Ministry of Education, Jiangnan University, Wuxi, China
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
| | - Hui Li
- Laboratory of Pharmaceutical Engineering, School of Life Science and Health Engineering, Jiangnan University, Wuxi, China
| | - Jinsong Shi
- Laboratory of Pharmaceutical Engineering, School of Life Science and Health Engineering, Jiangnan University, Wuxi, China
| | - Zhenghong Xu
- Biotechnology of Ministry of Education, Jiangnan University, Wuxi, China
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
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C-di-AMP Is a Second Messenger in Corynebacterium glutamicum That Regulates Expression of a Cell Wall-Related Peptidase via a Riboswitch. Microorganisms 2023; 11:microorganisms11020296. [PMID: 36838266 PMCID: PMC9960051 DOI: 10.3390/microorganisms11020296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/25/2023] Open
Abstract
Cyclic di-adenosine monophosphate (c-di-AMP) is a bacterial second messenger discovered in Bacillus subtilis and involved in potassium homeostasis, cell wall maintenance and/or DNA stress response. As the role of c-di-AMP has been mostly studied in Firmicutes, we sought to increase the understanding of its role in Actinobacteria, namely in Corynebacterium glutamicum. This organism is a well-known industrial production host and a model organism for pathogens, such as C. diphtheriae or Mycobacterium tuberculosis. Here, we identify and analyze the minimal set of two C. glutamicum enzymes, the diadenylate cyclase DisA and the phosphodiesterase PdeA, responsible for c-di-AMP metabolism. DisA synthesizes c-di-AMP from two molecules of ATP, whereas PdeA degrades c-di-AMP, as well as the linear degradation intermediate phosphoadenylyl-(3'→5')-adenosine (pApA) to two molecules of AMP. Here, we show that a ydaO/kimA-type c-di-AMP-dependent riboswitch controls the expression of the strictly regulated cell wall peptidase gene nlpC in C. glutamicum. In contrast to previously described members of the ydaO/kimA-type riboswitches, our results suggest that the C. glutamicum nlpC riboswitch likely affects the translation instead of the transcription of its downstream gene. Although strongly regulated by different mechanisms, we show that the absence of nlpC, the first known regulatory target of c-di-AMP in C. glutamicum, is not detrimental for this organism under the tested conditions.
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3
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Kranz A, Polen T, Kotulla C, Arndt A, Bosco G, Bussmann M, Chattopadhyay A, Cramer A, Davoudi CF, Degner U, Diesveld R, Freiherr von Boeselager R, Gärtner K, Gätgens C, Georgi T, Geraths C, Haas S, Heyer A, Hünnefeld M, Ishige T, Kabus A, Kallscheuer N, Kever L, Klaffl S, Kleine B, Kočan M, Koch-Koerfges A, Kraxner KJ, Krug A, Krüger A, Küberl A, Labib M, Lange C, Mack C, Maeda T, Mahr R, Majda S, Michel A, Morosov X, Müller O, Nanda AM, Nickel J, Pahlke J, Pfeifer E, Platzen L, Ramp P, Rittmann D, Schaffer S, Scheele S, Spelberg S, Schulte J, Schweitzer JE, Sindelar G, Sorger-Herrmann U, Spelberg M, Stansen C, Tharmasothirajan A, Ooyen JV, van Summeren-Wesenhagen P, Vogt M, Witthoff S, Zhu L, Eikmanns BJ, Oldiges M, Schaumann G, Baumgart M, Brocker M, Eggeling L, Freudl R, Frunzke J, Marienhagen J, Wendisch VF, Bott M. A manually curated compendium of expression profiles for the microbial cell factory Corynebacterium glutamicum. Sci Data 2022; 9:594. [PMID: 36182956 PMCID: PMC9526701 DOI: 10.1038/s41597-022-01706-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 08/18/2022] [Indexed: 11/12/2022] Open
Abstract
Corynebacterium glutamicum is the major host for the industrial production of amino acids and has become one of the best studied model organisms in microbial biotechnology. Rational strain construction has led to an improvement of producer strains and to a variety of novel producer strains with a broad substrate and product spectrum. A key factor for the success of these approaches is detailed knowledge of transcriptional regulation in C. glutamicum. Here, we present a large compendium of 927 manually curated microarray-based transcriptional profiles for wild-type and engineered strains detecting genome-wide expression changes of the 3,047 annotated genes in response to various environmental conditions or in response to genetic modifications. The replicates within the 927 experiments were combined to 304 microarray sets ordered into six categories that were used for differential gene expression analysis. Hierarchical clustering confirmed that no outliers were present in the sets. The compendium provides a valuable resource for future fundamental and applied research with C. glutamicum and contributes to a systemic understanding of this microbial cell factory.Measurement(s) | Gene Expression Analysis | Technology Type(s) | Two Color Microarray | Factor Type(s) | WT condition A vs. WT condition B • Plasmid-based gene overexpression in parental strain vs. parental strain with empty vector control • Deletion mutant vs. parental strain | Sample Characteristic - Organism | Corynebacterium glutamicum | Sample Characteristic - Environment | laboratory environment | Sample Characteristic - Location | Germany |
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Affiliation(s)
- Angela Kranz
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany. .,IBG-4: Bioinformatics, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Tino Polen
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Christian Kotulla
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Annette Arndt
- Institute of Microbiology and Biotechnology, University of Ulm, D-89069, Ulm, Germany
| | - Graziella Bosco
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Michael Bussmann
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Ava Chattopadhyay
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Annette Cramer
- Institute of Microbiology and Biotechnology, University of Ulm, D-89069, Ulm, Germany
| | - Cedric-Farhad Davoudi
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Ursula Degner
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Ramon Diesveld
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | | | - Kim Gärtner
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Cornelia Gätgens
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Tobias Georgi
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Christian Geraths
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Sabine Haas
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Antonia Heyer
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Max Hünnefeld
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Takeru Ishige
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Armin Kabus
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Nicolai Kallscheuer
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Larissa Kever
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Simon Klaffl
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Britta Kleine
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Martina Kočan
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Abigail Koch-Koerfges
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Kim J Kraxner
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Andreas Krug
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Aileen Krüger
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Andreas Küberl
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Mohamed Labib
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Christian Lange
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Christina Mack
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Tomoya Maeda
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Regina Mahr
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Stephan Majda
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Andrea Michel
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Xenia Morosov
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Olga Müller
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Arun M Nanda
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Jens Nickel
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Jennifer Pahlke
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Eugen Pfeifer
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Laura Platzen
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Paul Ramp
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Doris Rittmann
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Steffen Schaffer
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Sandra Scheele
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Stephanie Spelberg
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Julia Schulte
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Jens-Eric Schweitzer
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Georg Sindelar
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Ulrike Sorger-Herrmann
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Markus Spelberg
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Corinna Stansen
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Apilaasha Tharmasothirajan
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Jan van Ooyen
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | | | - Michael Vogt
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Sabrina Witthoff
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Lingfeng Zhu
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Bernhard J Eikmanns
- Institute of Microbiology and Biotechnology, University of Ulm, D-89069, Ulm, Germany
| | - Marco Oldiges
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Georg Schaumann
- SenseUp GmbH, c/o Campus Forschungszentrum, Wilhelm-Johnen-Strasse, D-52425, Jülich, Germany
| | - Meike Baumgart
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Melanie Brocker
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Lothar Eggeling
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Roland Freudl
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Julia Frunzke
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Jan Marienhagen
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Volker F Wendisch
- Genetics of Prokaryotes, Biology & CeBiTec, Bielefeld University, Universitaetsstr. 25, D-33615, Bielefeld, Germany
| | - Michael Bott
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, D-52425, Jülich, Germany.
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Development of a novel platform for recombinant protein production in Corynebacterium glutamicum on ethanol. Synth Syst Biotechnol 2022; 7:765-774. [PMID: 35387228 PMCID: PMC8942793 DOI: 10.1016/j.synbio.2022.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/04/2022] [Accepted: 03/15/2022] [Indexed: 02/03/2023] Open
Abstract
Corynebacterium glutamicum represents an emerging recombinant protein expression factory due to its ideal features for protein secretion, but its applicability is harmed by the lack of an autoinduction system with tight regulation and high yield. Here, we propose a new recombinant protein manufacturing platform that leverages ethanol as both a delayed carbon source and an inducer. First, we reanalysed the native inducible promoter PICL from the acetate uptake operon and found that its limited capacity is the result of the inadequate translation initial architecture. The two strategies of bicistronic design and ribozyme-based insulator can ensure the high activity of this promoter. Next, through transcriptional engineering that alters transcription factor binding sites (TFBSs) and the first transcribed sequence, the truncated promoter PA256 with a dramatically higher transcription level was generated. When producing the superfolder green fluorescent protein (sfGFP) under 1% ethanol conditions, PA256 exhibited substantially lower protein accumulation in prophase but an approximately 2.5-fold greater final yield than the strong promoter PH36. This superior expression mode was further validated using two secreted proteins, camelid antibody fragment (VHH) and endoxylanase (XynA). Furthermore, utilizing CRISPRi technology, ethanol utilization blocking strains were created, and PA256 was shown to be impaired in the phosphotransacetylase (PTA) knockdown strains, indicating that ethanol metabolism into the tricarboxylic acid cycle is required for PA256 upregulation. Finally, this platform was applied to produce the “de novo design” protein NEO-2/15, and by introducing the N-propeptide of CspB, NEO-2/15 was effectively secreted with the accumulation 281 mg/L obtained after 24 h of shake-flask fermentation. To the best of our knowledge, this is the first report of NEO-2/15 secretory overexpression.
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Jeong H, Kim Y, Lee HS. OsnR is an autoregulatory negative transcription factor controlling redox-dependent stress responses in Corynebacterium glutamicum. Microb Cell Fact 2021; 20:203. [PMID: 34663317 PMCID: PMC8524982 DOI: 10.1186/s12934-021-01693-1] [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: 06/17/2021] [Accepted: 10/07/2021] [Indexed: 01/11/2023] Open
Abstract
Background Corynebacterium glutamicum is used in the industrial production of amino acids and nucleotides. During the course of fermentation, C. glutamicum cells face various stresses and employ multiple regulatory genes to cope with the oxidative stress. The osnR gene plays a negative regulatory role in redox-dependent oxidative-stress responses, but the underlying mechanism is not known yet. Results Overexpression of the osnR gene in C. glutamicum affected the expression of genes involved in the mycothiol metabolism. ChIP-seq analysis revealed that OsnR binds to the promoter region of multiple genes, including osnR and cg0026, which seems to function in the membrane-associated redox metabolism. Studies on the role of the osnR gene involving in vitro assays employing purified OsnR proteins and in vivo physiological analyses have identified that OsnR inhibits the transcription of its own gene. Further, oxidant diamide stimulates OsnR-binding to the promoter region of the osnR gene. The genes affected by the overexpression of osnR have been found to be under the control of σH. In the osnR-overexpressing strain, the transcription of sigH is significantly decreased and the stimulation of sigH transcription by external stress is lost, suggesting that osnR and sigH form an intimate regulatory network. Conclusions Our study suggests that OsnR not only functions as a transcriptional repressor of its own gene and of those involved in redox-dependent stress responses but also participates in the global transcriptional regulation by controlling the transcription of other master regulators, such as sigH. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01693-1.
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Affiliation(s)
- Haeri Jeong
- 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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The PhoPR two-component system responds to oxygen deficiency and regulates the pathways for energy supply in Corynebacterium glutamicum. World J Microbiol Biotechnol 2021; 37:160. [PMID: 34436681 DOI: 10.1007/s11274-021-03131-1] [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: 08/05/2020] [Accepted: 08/18/2021] [Indexed: 10/20/2022]
Abstract
The PhoPR two-component system, a highly conserved system in corynebacteria and mycobacteria, is involved in the cellular response to environmental stress. When analysing the transcriptomic data of Corynebacterium glutamicum strains under different dissolved oxygen (DO) levels, PhoPR was found to be the most responsive two-component system to DO changes. Here, we systematically investigated the expression of PhoPR in response to different DO levels and its impact on genes related to global regulation and energy metabolism. Using Green fluorescent protein as a reporter, we confirmed that PhoPR was significantly upregulated upon decrease of DO. Through real-time quantitative PCR and electrophoretic mobility shift assay, we found that the effector protein PhoP directly activated glxR (encoding a global regulator), pfk and gapA (encoding the glycolytic enzymes) and ctaD (encoding cytochrome c in the electron transport chain), while downregulated aceE and gltA (encoding the TCA cycle enzymes). Overexpression of phoP or phoR resulted in a decreased intracellular NAD+/NADH ratio and increased intracellular ATP level, consistent with the gene expression changes regulated by PhoP. These results reveal the PhoPR system respond to oxygen deficiency and is responsible for the regulation of pathways involved in the sustainability of the energy levels required under low oxygen conditions. Our findings in this study not only provide new insights into the adaptation pathways of C. glutamicum in response to low oxygen conditions but also identify new possible genetic targets for the construction of the new cell factories aimed toward industrial applications.
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Hoffmann SL, Kohlstedt M, Jungmann L, Hutter M, Poblete-Castro I, Becker J, Wittmann C. Cascaded valorization of brown seaweed to produce l-lysine and value-added products using Corynebacterium glutamicum streamlined by systems metabolic engineering. Metab Eng 2021; 67:293-307. [PMID: 34314893 DOI: 10.1016/j.ymben.2021.07.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 06/23/2021] [Accepted: 07/22/2021] [Indexed: 12/15/2022]
Abstract
Seaweeds emerge as promising third-generation renewable for sustainable bioproduction. In the present work, we valorized brown seaweed to produce l-lysine, the world's leading feed amino acid, using Corynebacterium glutamicum, which was streamlined by systems metabolic engineering. The mutant C. glutamicum SEA-1 served as a starting point for development because it produced small amounts of l-lysine from mannitol, a major seaweed sugar, because of the deletion of its arabitol repressor AtlR and its engineered l-lysine pathway. Starting from SEA-1, we systematically optimized the microbe to redirect excess NADH, formed on the sugar alcohol, towards NADPH, required for l-lysine synthesis. The mannitol dehydrogenase variant MtlD D75A, inspired by 3D protein homology modelling, partly generated NADPH during the oxidation of mannitol to fructose, leading to a 70% increased l-lysine yield in strain SEA-2C. Several rounds of strain engineering further increased NADPH supply and l-lysine production. The best strain, SEA-7, overexpressed the membrane-bound transhydrogenase pntAB together with codon-optimized gapN, encoding NADPH-dependent glyceraldehyde 3-phosphate dehydrogenase, and mak, encoding fructokinase. In a fed-batch process, SEA-7 produced 76 g L-1l-lysine from mannitol at a yield of 0.26 mol mol-1 and a maximum productivity of 2.1 g L-1 h-1. Finally, SEA-7 was integrated into seaweed valorization cascades. Aqua-cultured Laminaria digitata, a major seaweed for commercial alginate, was extracted and hydrolyzed enzymatically, followed by recovery and clean-up of pure alginate gum. The residual sugar-based mixture was converted to l-lysine at a yield of 0.27 C-mol C-mol-1 using SEA-7. Second, stems of the wild-harvested seaweed Durvillaea antarctica, obtained as waste during commercial processing of the blades for human consumption, were extracted using acid treatment. Fermentation of the hydrolysate using SEA-7 provided l-lysine at a yield of 0.40 C-mol C-mol-1. Our findings enable improvement of the efficiency of seaweed biorefineries using tailor-made C. glutamicum strains.
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Affiliation(s)
- Sarah Lisa Hoffmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Michael Kohlstedt
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Lukas Jungmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Michael Hutter
- Centre for Bioinformatics, Saarland University, Saarbrücken, Germany
| | | | - Judith Becker
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
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8
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Pátek M, Grulich M, Nešvera J. Stress response in Rhodococcus strains. Biotechnol Adv 2021; 53:107698. [PMID: 33515672 DOI: 10.1016/j.biotechadv.2021.107698] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 12/13/2022]
Abstract
Rhodococci are bacteria which can survive under various extreme conditions, in the presence of toxic compounds, and in other hostile habitats. Their tolerance of unfavorable conditions is associated with the structure of their cell wall and their large array of enzymes, which degrade or detoxify harmful compounds. Their physiological and biotechnological properties, together with tools for their genetic manipulation, enable us to apply them in biotransformations, biodegradation and bioremediation. Many such biotechnological applications cause stresses that positively or negatively affect their efficiency. Whereas numerous reviews on rhodococci described their enzyme activities, the optimization of degradation or production processes, and corresponding technological solutions, only a few reviews discussed some specific effects of stresses on the physiology of rhodococci and biotechnological processes. This review aims to comprehensively describe individual stress responses in Rhodococcus strains, the interconnection of different types of stresses and their consequences for cell physiology. We examine here the responses to (1) environmental stresses (desiccation, heat, cold, osmotic and pH stress), (2) the presence of stress-inducing compounds (metals, organic compounds and antibiotics) in the environment (3) starvation and (4) stresses encountered during biotechnological applications. Adaptations of the cell envelope, the formation of multicellular structures and stresses induced by the interactions of hosts with pathogenic rhodococci are also included. The roles of sigma factors of RNA polymerase in the global regulation of stress responses in rhodococci are described as well. Although the review covers a large number of stressful conditions, our intention was to provide an overview of the selected stress responses and their possible connection to biotechnological processes, not an exhaustive survey of the scientific literature. The findings on stress responses summarized in this review and the demonstration of gaps in current knowledge may motivate researchers working to fill these gaps.
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Affiliation(s)
- Miroslav Pátek
- Institute of Microbiology of the CAS, v. v. i., Prague, Czech Republic.
| | - Michal Grulich
- Institute of Microbiology of the CAS, v. v. i., Prague, Czech Republic.
| | - Jan Nešvera
- Institute of Microbiology of the CAS, v. v. i., Prague, Czech Republic.
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9
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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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10
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Sander KB, Chung D, Klingeman DM, Giannone RJ, Rodriguez M, Whitham J, Hettich RL, Davison BH, Westpheling J, Brown SD. Gene targets for engineering osmotolerance in Caldicellulosiruptor bescii. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:50. [PMID: 32190115 PMCID: PMC7071700 DOI: 10.1186/s13068-020-01690-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 02/27/2020] [Indexed: 05/05/2023]
Abstract
BACKGROUND Caldicellulosiruptor bescii, a promising biocatalyst being developed for use in consolidated bioprocessing of lignocellulosic materials to ethanol, grows poorly and has reduced conversion at elevated medium osmolarities. Increasing tolerance to elevated fermentation osmolarities is desired to enable performance necessary of a consolidated bioprocessing (CBP) biocatalyst. RESULTS Two strains of C. bescii showing growth phenotypes in elevated osmolarity conditions were identified. The first strain, ORCB001, carried a deletion of the FapR fatty acid biosynthesis and malonyl-CoA metabolism repressor and had a severe growth defect when grown in high-osmolarity conditions-introduced as the addition of either ethanol, NaCl, glycerol, or glucose to growth media. The second strain, ORCB002, displayed a growth rate over three times higher than its genetic parent when grown in high-osmolarity medium. Unexpectedly, a genetic complement ORCB002 exhibited improved growth, failing to revert the observed phenotype, and suggesting that mutations other than the deleted transcription factor (the fruR/cra gene) are responsible for the growth phenotype observed in ORCB002. Genome resequencing identified several other genomic alterations (three deleted regions, three substitution mutations, one silent mutation, and one frameshift mutation), which may be responsible for the observed increase in osmolarity tolerance in the fruR/cra-deficient strain, including a substitution mutation in dnaK, a gene previously implicated in osmoresistance in bacteria. Differential expression analysis and transcription factor binding site inference indicates that FapR negatively regulates malonyl-CoA and fatty acid biosynthesis, as it does in many other bacteria. FruR/Cra regulates neighboring fructose metabolism genes, as well as other genes in global manner. CONCLUSIONS Two systems able to effect tolerance to elevated osmolarities in C. bescii are identified. The first is fatty acid biosynthesis. The other is likely the result of one or more unintended, secondary mutations present in another transcription factor deletion strain. Though the locus/loci and mechanism(s) responsible remain unknown, candidate mutations are identified, including a mutation in the dnaK chaperone coding sequence. These results illustrate both the promise of targeted regulatory manipulation for osmotolerance (in the case of fapR) and the challenges (in the case of fruR/cra).
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Affiliation(s)
- Kyle B. Sander
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Bredesen Center for Interdisciplinary Graduate Research and Education, University of Tennessee, Knoxville, TN USA
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN USA
- Present Address: Department of Bioengineering, University of California, Berkeley, Berkeley, CA USA
| | - Daehwan Chung
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Department of Genetics, University of Georgia, Athens, GA USA
- Present Address: National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Dawn M. Klingeman
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Richard J. Giannone
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Miguel Rodriguez
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Jason Whitham
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Present Address: Becton Dickinson Diagnostics, Sparks Glencoe, MD USA
| | - Robert L. Hettich
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Brian H. Davison
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Bredesen Center for Interdisciplinary Graduate Research and Education, University of Tennessee, Knoxville, TN USA
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Janet Westpheling
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Department of Genetics, University of Georgia, Athens, GA USA
| | - Steven D. Brown
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Bredesen Center for Interdisciplinary Graduate Research and Education, University of Tennessee, Knoxville, TN USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
- Present Address: LanzaTech, Skokie, IL USA
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11
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Dostálová H, Busche T, Holátko J, Rucká L, Štěpánek V, Barvík I, Nešvera J, Kalinowski J, Pátek M. Overlap of Promoter Recognition Specificity of Stress Response Sigma Factors SigD and SigH in Corynebacterium glutamicum ATCC 13032. Front Microbiol 2019; 9:3287. [PMID: 30687273 PMCID: PMC6338062 DOI: 10.3389/fmicb.2018.03287] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 12/17/2018] [Indexed: 12/27/2022] Open
Abstract
Corynebacterium glutamicum ATCC 13032 harbors five sigma subunits of RNA polymerase belonging to Group IV, also called extracytoplasmic function (ECF) σ factors. These factors σC, σD, σE, σH, and σM are mostly involved in stress responses. The role of σD consists in the control of cell wall integrity. The σD regulon is involved in the synthesis of components of the mycomembrane which is part of the cell wall in C. glutamicum. RNA sequencing of the transcriptome from a strain overexpressing the sigD gene provided 29 potential σD-controlled genes and enabled us to precisely localize their transcriptional start sites. Analysis of the respective promoters by both in vitro transcription and the in vivo two-plasmid assay confirmed that transcription of 11 of the tested genes is directly σD-dependent. The key sequence elements of all these promoters were found to be identical or closely similar to the motifs -35 GTAACA/G and -10 GAT. Surprisingly, nearly all of these σD-dependent promoters were also active to a much lower extent with σHin vivo and one (Pcg0607) also in vitro, although the known highly conserved consensus sequence of the σH-dependent promoters is different (-35 GGAAT/C and -10 GTT). In addition to the activity of σH at the σD-controlled promoters, we discovered separated or overlapping σA- or σB-regulated or σH-regulated promoters within the upstream region of 8 genes of the σD-regulon. We found that phenol in the cultivation medium acts as a stress factor inducing expression of some σD-dependent genes. Computer modeling revealed that σH binds to the promoter DNA in a similar manner as σD to the analogous promoter elements. The homology models together with mutational analysis showed that the key amino acids, Ala 60 in σD and Lys 53 in σH, bind to the second nucleotide within the respective -10 promoter elements (GAT and GTT, respectively). The presented data obtained by integrating in vivo, in vitro and in silico approaches demonstrate that most of the σD-controlled genes also belong to the σH-regulon and are also transcribed from the overlapping or closely located housekeeping (σA-regulated) and/or general stress (σB-regulated) promoters.
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Affiliation(s)
- Hana Dostálová
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
| | - Tobias Busche
- Centrum für Biotechnologie, Universität Bielefeld, Bielefeld, Germany
| | - Jiří Holátko
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
| | - Lenka Rucká
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
| | - Václav Štěpánek
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
| | - Ivan Barvík
- Institute of Physics, Faculty of Mathematics and Physics, Charles University, Prague, Czechia
| | - Jan Nešvera
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
| | - Jörn Kalinowski
- Centrum für Biotechnologie, Universität Bielefeld, Bielefeld, Germany
| | - Miroslav Pátek
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
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12
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Große C, Poehlein A, Blank K, Schwarzenberger C, Schleuder G, Herzberg M, Nies DH. The third pillar of metal homeostasis inCupriavidus metalliduransCH34: preferences are controlled by extracytoplasmic function sigma factors. Metallomics 2019; 11:291-316. [DOI: 10.1039/c8mt00299a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
InC. metallidurans, a network of 11 extracytoplasmic function sigma factors forms the third pillar of metal homeostasis acting in addition to the metal transportome and metal repositories as the first and second pillar.
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Affiliation(s)
- Cornelia Große
- Molecular Microbiology
- Martin-Luther-University Halle-Wittenberg
- Kurt-Mothes-Str. 3
- 06099 Halle (Saale)
- Germany
| | - Anja Poehlein
- Göttingen Genomics Laboratory
- Georg-August-University Göttingen, Grisebachstr. 8
- 37077 Göttingen
- Germany
| | - Kathrin Blank
- Molecular Microbiology
- Martin-Luther-University Halle-Wittenberg
- Kurt-Mothes-Str. 3
- 06099 Halle (Saale)
- Germany
| | - Claudia Schwarzenberger
- Molecular Microbiology
- Martin-Luther-University Halle-Wittenberg
- Kurt-Mothes-Str. 3
- 06099 Halle (Saale)
- Germany
| | - Grit Schleuder
- Molecular Microbiology
- Martin-Luther-University Halle-Wittenberg
- Kurt-Mothes-Str. 3
- 06099 Halle (Saale)
- Germany
| | - Martin Herzberg
- Molecular Microbiology
- Martin-Luther-University Halle-Wittenberg
- Kurt-Mothes-Str. 3
- 06099 Halle (Saale)
- Germany
| | - Dietrich H. Nies
- Molecular Microbiology
- Martin-Luther-University Halle-Wittenberg
- Kurt-Mothes-Str. 3
- 06099 Halle (Saale)
- Germany
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13
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Wei H, Ma Y, Chen Q, Cui Y, Du L, Ma Q, Li Y, Xie X, Chen N. Identification and application of a novel strong constitutive promoter in Corynebacterium glutamicum. ANN MICROBIOL 2018. [DOI: 10.1007/s13213-018-1344-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022] Open
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14
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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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15
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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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16
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Schulte J, Baumgart M, Bott M. Identification of the cAMP phosphodiesterase CpdA as novel key player in cAMP-dependent regulation in Corynebacterium glutamicum. Mol Microbiol 2016; 103:534-552. [PMID: 27862445 DOI: 10.1111/mmi.13574] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2016] [Indexed: 02/03/2023]
Abstract
The second messenger cyclic AMP (cAMP) plays an important role in the metabolism of Corynebacterium glutamicum, as the global transcriptional regulator GlxR requires complex formation with cAMP to become active. Whereas a membrane-bound adenylate cyclase, CyaB, was shown to be involved in cAMP synthesis, enzymes catalyzing cAMP degradation have not been described yet. In this study we identified a class II cAMP phosphodiesterase named CpdA (Cg2761), homologs of which are present in many Actinobacteria. The purified enzyme has a Kmapp value of 2.5 ± 0.3 mM for cAMP and a Vmaxapp of 33.6 ± 4.3 µmol min-1 mg-1 . A ΔcpdA mutant showed a twofold increased cAMP level on glucose and reduced growth rates on all carbon sources tested. A transcriptome comparison revealed 247 genes with a more than twofold altered mRNA level in the ΔcpdA mutant, 82 of which are known GlxR targets. Expression of cpdA was positively regulated by GlxR, thereby creating a negative feedback loop allowing to counteract high cAMP levels. The results show that CpdA plays a key role in the control of the cellular cAMP concentration and GlxR activity and is crucial for optimal metabolism and growth of C. glutamicum.
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Affiliation(s)
- Julia Schulte
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, 52425, Germany
| | - Meike Baumgart
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, 52425, Germany
| | - Michael Bott
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, 52425, Germany
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17
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Shah A, Eikmanns BJ. Transcriptional Regulation of the β-Type Carbonic Anhydrase Gene bca by RamA in Corynebacterium glutamicum. PLoS One 2016; 11:e0154382. [PMID: 27119954 PMCID: PMC4847777 DOI: 10.1371/journal.pone.0154382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 04/12/2016] [Indexed: 11/25/2022] Open
Abstract
Carbonic anhydrase catalyzes the reversible hydration of carbon dioxide to bicarbonate and maintains the balance of CO2/HCO3- in the intracellular environment, specifically for carboxylation/decarboxylation reactions. In Corynebacterium glutamicum, two putative genes, namely the bca (cg2954) and gca (cg0155) genes, coding for β-type and γ-type carbonic anhydrase, respectively, have been identified. We here analyze the transcriptional organization of these genes. The transcriptional start site (TSS) of the bca gene was shown to be the first nucleotide "A" of its putative translational start codon (ATG) and thus, bca codes for a leaderless transcript. The TSS of the gca gene was identified as an "A" residue located at position -20 relative to the first nucleotide of the annotated translational start codon of the cg0154 gene, which is located immediately upstream of gca. Comparative expression analysis revealed carbon source-dependent regulation of the bca gene, with 1.5- to 2-fold lower promoter activity in cells grown on acetate as compared to glucose as sole carbon source. Based on higher expression of bca in a mutant deficient of the regulator of acetate metabolism RamA as compared to the wild-type of C. glutamicum and based on the binding of His-tagged RamA protein to the bca promoter region, we here present evidence that RamA negatively regulates expression of bca in C. glutamicum. Functional characterization of a gca deletion mutant of C. glutamicum revealed the same growth characteristics of C. glutamicum ∆gca as that of wild-type C. glutamicum and no effect on expression of the bca gene.
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Affiliation(s)
- Adnan Shah
- Institute of Microbiology and Biotechnology, University of Ulm, D-89069 Ulm, Germany
| | - Bernhard J. Eikmanns
- Institute of Microbiology and Biotechnology, University of Ulm, D-89069 Ulm, Germany
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18
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Becker J, Gießelmann G, Hoffmann SL, Wittmann C. Corynebacterium glutamicum for Sustainable Bioproduction: From Metabolic Physiology to Systems Metabolic Engineering. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2016; 162:217-263. [DOI: 10.1007/10_2016_21] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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