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Loi VV, Busche T, Kuropka B, Müller S, Methling K, Lalk M, Kalinowski J, Antelmann H. Staphylococcus aureus adapts to the immunometabolite itaconic acid by inducing acid and oxidative stress responses including S-bacillithiolations and S-itaconations. Free Radic Biol Med 2023; 208:859-876. [PMID: 37793500 DOI: 10.1016/j.freeradbiomed.2023.09.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/21/2023] [Accepted: 09/26/2023] [Indexed: 10/06/2023]
Abstract
Staphylococcus aureus is a major pathogen, which has to defend against reactive oxygen and electrophilic species encountered during infections. Activated macrophages produce the immunometabolite itaconate as potent electrophile and antimicrobial upon pathogen infection. In this work, we used transcriptomics, metabolomics and shotgun redox proteomics to investigate the specific stress responses, metabolic changes and redox modifications caused by sublethal concentrations of itaconic acid in S. aureus. In the RNA-seq transcriptome, itaconic acid caused the induction of the GlnR, KdpDE, CidR, SigB, GraRS, PerR, CtsR and HrcA regulons and the urease-encoding operon, revealing an acid and oxidative stress response and impaired proteostasis. Neutralization using external urea as ammonium source improved the growth and decreased the expression of the glutamine synthetase-controlling GlnR regulon, indicating that S. aureus experienced ammonium starvation upon itaconic acid stress. In the extracellular metabolome, the amounts of acetate and formate were decreased, while secretion of pyruvate and the neutral product acetoin were strongly enhanced to avoid intracellular acidification. Exposure to itaconic acid affected the amino acid uptake and metabolism as revealed by the strong intracellular accumulation of lysine, threonine, histidine, aspartate, alanine, valine, leucine, isoleucine, cysteine and methionine. In the proteome, itaconic acid caused widespread S-bacillithiolation and S-itaconation of redox-sensitive antioxidant and metabolic enzymes, ribosomal proteins and translation factors in S. aureus, supporting its oxidative and electrophilic mode of action in S. aureus. In phenotype analyses, the catalase KatA, the low molecular weight thiol bacillithiol and the urease provided protection against itaconic acid-induced oxidative and acid stress in S. aureus. Altogether, our results revealed that under physiological infection conditions, such as in the acidic phagolysome, itaconic acid is a highly effective antimicrobial against multi-resistant S. aureus isolates, which acts as weak acid causing an acid, oxidative and electrophilic stress response, leading to S-bacillithiolation and itaconation.
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Affiliation(s)
- Vu Van Loi
- Freie Universität Berlin, Institute of Biology-Microbiology, D-14195, Berlin, Germany
| | - Tobias Busche
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, D-33615, Bielefeld, Germany
| | - Benno Kuropka
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, D-14195, Berlin, Germany
| | - Susanne Müller
- Freie Universität Berlin, Institute of Biology-Microbiology, D-14195, Berlin, Germany
| | - Karen Methling
- Department of Cellular Biochemistry and Metabolomics, University of Greifswald, 17487, Greifswald, Germany
| | - Michael Lalk
- Department of Cellular Biochemistry and Metabolomics, University of Greifswald, 17487, Greifswald, Germany
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, D-33615, Bielefeld, Germany
| | - Haike Antelmann
- Freie Universität Berlin, Institute of Biology-Microbiology, D-14195, Berlin, Germany.
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Luo Z, Li Y, Chen B, Lei M, Zhang N, Zhang X, Li J. Effect of free ammonia on partial denitrification: Long-term performance, mechanism, and feasibility of PD/Anammox-FBBR for mature landfill leachate treatment. WATER RESEARCH 2023; 243:120238. [PMID: 37506632 DOI: 10.1016/j.watres.2023.120238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/25/2023] [Accepted: 06/16/2023] [Indexed: 07/30/2023]
Abstract
As a stable and effective approach for NO2--N accumulation, partial denitrification (PD) could significantly cut down operation cost, and PD/Anammox (PD/A) is a promising nitrogen removal process in wastewater treatment. The biotoxicity of free ammonia (FA) to nitrifying bacteria and anammox bacteria has been demonstrated, while whether FA affects PD bacteria is an open question. Here, long-term operation of PD-fixed bed biofilm reactor (PD-FBBR) treating synthetic wastewater and mature landfill leachate was conducted to reveal the mechanism concerning the effect of FA on PD bacteria. Stable NO2--N accumulation was achieved with NO3--N to NO2--N transformation ratio (NTR) of 60-70% during 280-day operation with FA ranged from 0 to 20.71 ± 0.23 mg/L, while NTR decreased and maintained at ∼30% when FA reached 40.59 ± 0.19 mg/L. Specific NOx--N reduction rate improved at low FA concentration (< 12 mg/L), while high FA level (> 25 mg/L) had inhibitory effect on PD bacteria. Under FA stress, more extracellular polymeric substances (EPS) were secreted, and the glnA gene abundance, glutamine synthase concentration, and glutamine concentration in cell and EPS significantly increased, indicating the enhancement of glutamine biosynthesis in PD bacteria for ammonia assimilation played an important role in response to FA stress. Metagenomic sequencing showed that FA stimulated the upregulation of narK (NO3--N/NO2--N antiporter) gene abundance and enhanced uptake of NO3--N and extrusion of NO2--N. Comamonas, unclassified_f__Comamonadaceae and Thauera were highly enriched in biofilm, which played a key role in the stable NO2--N accumulation. Furthermore, a novel two stage PD/A-FBBR was applied to mature landfill leachate treatment, and satisfactory total inorganic nitrogen removal efficiency ranged from 81.38 ± 3.56% to 89.16 ± 1.57% was obtained at relatively low COD/NO3--N of 2.57-2.84. Overall, these findings demonstrated how PD bacteria respond to FA stress and confirmed the feasibility of PD/A process in high FA wastewater treatment.
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Affiliation(s)
- Zhizhan Luo
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Yong Li
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Bohan Chen
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Mengen Lei
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Naixin Zhang
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Xiaolei Zhang
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Ji Li
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China; Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
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He H, Li Y, Zhang L, Ding Z, Shi G. Understanding and application of Bacillus nitrogen regulation: A synthetic biology perspective. J Adv Res 2022:S2090-1232(22)00205-3. [PMID: 36103961 DOI: 10.1016/j.jare.2022.09.003] [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: 12/13/2021] [Revised: 08/22/2022] [Accepted: 09/05/2022] [Indexed: 10/14/2022] Open
Abstract
BACKGROUND Nitrogen sources play an essential role in maintaining the physiological and biochemical activity of bacteria. Nitrogen metabolism, which is the core of microorganism metabolism, makes bacteria able to autonomously respond to different external nitrogen environments by exercising complex internal regulatory networks to help them stay in an ideal state. Although various studies have been put forth to better understand this regulation in Bacillus, and many valuable viewpoints have been obtained, these views need to be presented systematically and their possible applications need to be specified. AIM OF REVIEW The intention is to provide a deep and comprehensive understanding of nitrogen metabolism in Bacillus, an important industrial microorganism, and thereby apply this regulatory logic to synthetic biology to improve biosynthesis competitiveness. In addition, the potential researches in the future are also discussed. KEY SCIENTIFIC CONCEPT OF REVIEW Understanding the meticulous regulation process of nitrogen metabolism in Bacillus not only could facilitate research on metabolic engineering but also could provide constructive insights and inspiration for studies of other microorganisms.
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Affiliation(s)
- Hehe He
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu Province 214122, PR China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu Province 214122, PR China
| | - Youran Li
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu Province 214122, PR China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu Province 214122, PR China.
| | - Liang Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu Province 214122, PR China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu Province 214122, PR China
| | - Zhongyang Ding
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu Province 214122, PR China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu Province 214122, PR China
| | - Guiyang Shi
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu Province 214122, PR China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu Province 214122, PR China.
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Iskhakova ZI, Zhuravleva DE, Heim C, Hartmann MD, Laykov AV, Forchhammer K, Kayumov AR. PotN represents a novel energy‐state sensing PII subfamily, occurring in firmicutes. FEBS J 2022; 289:5305-5321. [DOI: 10.1111/febs.16431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 02/19/2022] [Accepted: 03/10/2022] [Indexed: 01/19/2023]
Affiliation(s)
| | | | - Christopher Heim
- Department of Protein Evolution Max Planck Institute for Developmental Biology Tübingen Germany
| | - Marcus D. Hartmann
- Department of Protein Evolution Max Planck Institute for Developmental Biology Tübingen Germany
| | | | - Karl Forchhammer
- Institut für Mikrobiologie Eberhard‐Karls‐Universität Tübingen Germany
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Lv Q, Hu M, Tian L, Liu F, Wang Q, Xu M, Rao Z. Enhancing l-glutamine production in Corynebacterium glutamicum by rational metabolic engineering combined with a two-stage pH control strategy. BIORESOURCE TECHNOLOGY 2021; 341:125799. [PMID: 34425465 DOI: 10.1016/j.biortech.2021.125799] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
l-glutamine is a semi-essential amino acid widely used in the food and pharmaceutical industries. The microbial synthesis of l-glutamine is limited by lack of effective strains with high titer and safety. First, ARTP mutagenesis combined with high-throughput screening generated an l-glutamine-producing strain of Corynebacterium glutamicum with titer of 25.7 ± 2.7 g/L. Subsequently, a series of rational metabolic approaches were used to further improve l-glutamine production, which included increasing the carbon flow to l-glutamine (proB and NCgl1221 knockout), enhancing the catalytic efficiency of the key enzyme (glnE knockout and glnA screening and overexpression) and reinforcement of ATP regeneration (ppk overexpression and RBS optimization). Finally, we proposed a two-stage pH control strategy to address the inconsistent effect of pH on cell growth and l-glutamine production. These combined strategies led to a 186.0% increase of l-glutamine titer compared to that of the initial strain, reaching 73.5 ± 3.1 g/L with a yield of 0.368 ± 0.034 g/g glucose.
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Affiliation(s)
- Qinglan Lv
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China
| | - Mengkai Hu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China
| | - Lingzhi Tian
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China
| | - Fei Liu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China
| | - Qing Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China
| | - Meijuan Xu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China
| | - Zhiming Rao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, PR China.
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Frare R, Stritzler M, Pascuan C, Liebrenz K, Galindo-Sotomonte L, Soto G, Nikel PI, Ayub N. Elimination of GlnKAmtB affects serine biosynthesis and improves growth and stress tolerance of Escherichia coli under nutrient-rich conditions. FEMS Microbiol Lett 2021; 367:6006877. [PMID: 33242092 DOI: 10.1093/femsle/fnaa197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/24/2020] [Indexed: 12/16/2022] Open
Abstract
Nitrogen is a most important nutrient resource for Escherichia coli and other bacteria that harbor the glnKamtB operon, a high-affinity ammonium uptake system highly interconnected with cellular metabolism. Although this system confers an advantage to bacteria when growing under nitrogen-limiting conditions, little is known about the impact of these genes on microbial fitness under nutrient-rich conditions. Here, the genetically tractable E. coli BW25113 strain and its glnKamtB-null mutant (JW0441) were used to analyze the impact of GlnK-AmtB on growth rates and oxidative stress tolerance. Strain JW0441 showed a shorter initial lag phase, higher growth rate, higher citrate synthase activity, higher oxidative stress tolerance and lower expression of serA than strain BW25113 under nutrient-rich conditions, suggesting a fitness cost to increase metabolic plasticity associated with serine metabolism. The overexpression of serA in strain JW0441 resulted in a decreased growth rate and stress tolerance in nutrient-rich conditions similar to that of strain BW25113, suggesting that the negative influence on bacterial fitness imposed by GlnK-AmtB can be traced to the control of serine biosynthesis. Finally, we discuss the potential applications of glnKamtB mutants in bioproduction processes.
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Affiliation(s)
- Romina Frare
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto de Genética (IGEAF), INTA-CONICET, Buenos Aires, Argentina
| | - Margarita Stritzler
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto de Genética (IGEAF), INTA-CONICET, Buenos Aires, Argentina
| | - Cecilia Pascuan
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto de Genética (IGEAF), INTA-CONICET, Buenos Aires, Argentina
| | - Karen Liebrenz
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto de Genética (IGEAF), INTA-CONICET, Buenos Aires, Argentina
| | - Luisa Galindo-Sotomonte
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto de Genética (IGEAF), INTA-CONICET, Buenos Aires, Argentina
| | - Gabriela Soto
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto de Genética (IGEAF), INTA-CONICET, Buenos Aires, Argentina
| | - Pablo Iván Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Nicolás Ayub
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto de Genética (IGEAF), INTA-CONICET, Buenos Aires, Argentina
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7
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Benda M, Woelfel S, Faßhauer P, Gunka K, Klumpp S, Poehlein A, Kálalová D, Šanderová H, Daniel R, Krásný L, Stülke J. Quasi-essentiality of RNase Y in Bacillus subtilis is caused by its critical role in the control of mRNA homeostasis. Nucleic Acids Res 2021; 49:7088-7102. [PMID: 34157109 PMCID: PMC8266666 DOI: 10.1093/nar/gkab528] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 05/28/2021] [Accepted: 06/08/2021] [Indexed: 01/18/2023] Open
Abstract
RNA turnover is essential in all domains of life. The endonuclease RNase Y (rny) is one of the key components involved in RNA metabolism of the model organism Bacillus subtilis. Essentiality of RNase Y has been a matter of discussion, since deletion of the rny gene is possible, but leads to severe phenotypic effects. In this work, we demonstrate that the rny mutant strain rapidly evolves suppressor mutations to at least partially alleviate these defects. All suppressor mutants had acquired a duplication of an about 60 kb long genomic region encompassing genes for all three core subunits of the RNA polymerase—α, β, β′. When the duplication of the RNA polymerase genes was prevented by relocation of the rpoA gene in the B. subtilis genome, all suppressor mutants carried distinct single point mutations in evolutionary conserved regions of genes coding either for the β or β’ subunits of the RNA polymerase that were not tolerated by wild type bacteria. In vitro transcription assays with the mutated polymerase variants showed a severe decrease in transcription efficiency. Altogether, our results suggest a tight cooperation between RNase Y and the RNA polymerase to establish an optimal RNA homeostasis in B. subtilis cells.
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Affiliation(s)
- Martin Benda
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Simon Woelfel
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Patrick Faßhauer
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Katrin Gunka
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Stefan Klumpp
- Institute for the Dynamics of Complex Systems, Georg-August-University Göttingen, Göttingen, Germany
| | - Anja Poehlein
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Debora Kálalová
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Hana Šanderová
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Libor Krásný
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jörg Stülke
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
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Shen P, Niu D, Permaul K, Tian K, Singh S, Wang Z. Exploitation of ammonia-inducible promoters for enzyme overexpression in Bacillus licheniformis. J Ind Microbiol Biotechnol 2021; 48:6298226. [PMID: 34124759 PMCID: PMC9113418 DOI: 10.1093/jimb/kuab037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/07/2021] [Indexed: 12/13/2022]
Abstract
Ammonium hydroxide is conventionally used as an alkaline reagent and cost-effective nitrogen source in enzyme manufacturing processes. However, few ammonia-inducible enzyme expression systems have been described thus far. In this study, genomic-wide transcriptional changes in Bacillus licheniformis CBBD302 cultivated in media supplemented with ammonia were analyzed, resulting in identification of 1443 differently expressed genes, of which 859 genes were upregulated and 584 downregulated. Subsequently, the nucleotide sequences of ammonia-inducible promoters were analyzed and their functionally-mediated expression of amyL, encoding an α-amylase, was shown. TRNA_RS39005 (copA), TRNA_RS41250 (sacA), TRNA_RS23130 (pdpX), TRNA_RS42535 (ald), TRNA_RS31535 (plp), and TRNA_RS23240 (dfp) were selected out of the 859 upregulated genes and each showed higher transcription levels (FPKM values) in the presence of ammonia and glucose than that of the control. The promoters, PcopA from copA, PsacA from sacA, PpdpX from pdpX, Pald from ald, and Pplp from plp, except Pdfp from dfp, were able to mediate amyL expression and were significantly induced by ammonia. The highest enzyme expression level was mediated by Pplp and represented 23% more α-amylase activity after induction by ammonia in a 5-L fermenter. In conclusion, B. licheniformis possesses glucose-independent ammonia-inducible promoters, which can be used to mediate enzyme expression and therefore enhance the enzyme yield in fermentations conventionally fed with ammonia for pH adjustment and nitrogen supply.
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Affiliation(s)
- Peili Shen
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Dandan Niu
- Department of Biological Chemical Engineering, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Kugen Permaul
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, P. O. Box 1334, Durban 4001, South Africa
| | - Kangming Tian
- Department of Biological Chemical Engineering, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Suren Singh
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, P. O. Box 1334, Durban 4001, South Africa
| | - Zhengxiang Wang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.,Department of Biological Chemical Engineering, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin 300457, China
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Zhang H, Song L, Chen X, Li P. An Exploration of Seaweed Polysaccharides Stimulating Denitrifying Bacteria for Safer Nitrate Removal. Molecules 2021; 26:molecules26113390. [PMID: 34205200 PMCID: PMC8200018 DOI: 10.3390/molecules26113390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 11/16/2022] Open
Abstract
Excessive use of nitrogen fertilizer in intensively managed agriculture has resulted in abundant accumulation of nitrate in soil, which limits agriculture sustainability. How to reduce nitrate content is the key to alleviate secondary soil salinization. However, the microorganisms used in soil remediation cause some problems such as weak efficiency and short survival time. In this study, seaweed polysaccharides were used as stimulant to promote the rapid growth and safer nitrate removal of denitrifying bacteria. Firstly, the growth rate and NO3−-N removal capacity of three kinds of denitrifying bacteria, Bacillus subtilis (BS), Pseudomonas stutzeri (PS) and Pseudomonas putida (PP), were compared. The results showed that Bacillus subtilis (BS) had a faster growth rate and stronger nitrate removal ability. We then studied the effects of Enteromorpha linza polysaccharides (EP), carrageenan (CA), and sodium alginate (AL) on growth and denitrification performance of Bacillus subtilis (BS). The results showed that seaweed polysaccharides obviously promoted the growth of Bacillus subtilis (BS), and accelerated the reduction of NO3−-N. More importantly, the increased NH4+-N content could avoid excessive loss of nitrogen, and less NO2−-N accumulation could avoid toxic effects on plants. This new strategy of using denitrifying bacteria for safely remediating secondary soil salinization has a great significance.
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Affiliation(s)
- Hui Zhang
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao 266042, China; (H.Z.); (L.S.)
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lin Song
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao 266042, China; (H.Z.); (L.S.)
| | - Xiaolin Chen
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), No. 1 Wenhai Road, Qingdao 266237, China
- Correspondence: (X.C.); (P.L.); Tel.: +86-0532-82898702 (X.C.); +86-0532-82898707 (P.L.)
| | - Pengcheng Li
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), No. 1 Wenhai Road, Qingdao 266237, China
- Correspondence: (X.C.); (P.L.); Tel.: +86-0532-82898702 (X.C.); +86-0532-82898707 (P.L.)
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10
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Perin G, Fletcher T, Sagi-Kiss V, Gaboriau DCA, Carey MR, Bundy JG, Jones PR. Calm on the surface, dynamic on the inside. Molecular homeostasis of Anabaena sp. PCC 7120 nitrogen metabolism. PLANT, CELL & ENVIRONMENT 2021; 44:1885-1907. [PMID: 33608943 DOI: 10.1111/pce.14034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/12/2021] [Accepted: 02/13/2021] [Indexed: 06/12/2023]
Abstract
Nitrogen sources are all converted into ammonium/ia as a first step of assimilation. It is reasonable to expect that molecular components involved in the transport of ammonium/ia across biological membranes connect with the regulation of both nitrogen and central metabolism. We applied both genetic (i.e., Δamt mutation) and environmental treatments to a target biological system, the cyanobacterium Anabaena sp PCC 7120. The aim was to both perturb nitrogen metabolism and induce multiple inner nitrogen states, respectively, followed by targeted quantification of key proteins, metabolites and enzyme activities. The absence of AMT transporters triggered a substantial whole-system response, affecting enzyme activities and quantity of proteins and metabolites, spanning nitrogen and carbon metabolisms. Moreover, the Δamt strain displayed a molecular fingerprint indicating nitrogen deficiency even under nitrogen replete conditions. Contrasting with such dynamic adaptations was the striking near-complete lack of an externally measurable altered phenotype. We conclude that this species evolved a highly robust and adaptable molecular network to maintain homeostasis, resulting in substantial internal but minimal external perturbations. This analysis provides evidence for a potential role of AMT transporters in the regulatory/signalling network of nitrogen metabolism and the existence of a novel fourth regulatory mechanism controlling glutamine synthetase activity.
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Affiliation(s)
- Giorgio Perin
- Department of Life Sciences, Imperial College London, London, UK
| | - Tyler Fletcher
- Complex Carbohydrate Research Center and Department of Chemistry, University of Georgia, Athens, Georgia, USA
| | - Virag Sagi-Kiss
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - David C A Gaboriau
- Facility for Imaging by Light Microscopy, NHLI, Imperial College London, London, UK
| | - Mathew R Carey
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Jacob G Bundy
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Patrik R Jones
- Department of Life Sciences, Imperial College London, London, UK
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11
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Richts B, Lentes S, Poehlein A, Daniel R, Commichau FM. A Bacillus subtilis ΔpdxT mutant suppresses vitamin B6 limitation by acquiring mutations enhancing pdxS gene dosage and ammonium assimilation. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:218-233. [PMID: 33559288 DOI: 10.1111/1758-2229.12936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/03/2021] [Indexed: 06/12/2023]
Abstract
Pyridoxal-5'-phosphate (PLP), the biologically active form of vitamin B6, serves as a cofactor for many enzymes. The Gram-positive model bacterium Bacillus subtilis synthesizes PLP via the PdxST enzyme complex, consisting of the PdxT glutaminase and the PdxS PLP synthase subunits, respectively. PdxT converts glutamine to glutamate and ammonia of which the latter is channelled to PdxS. At high extracellular ammonium concentrations, the PdxS PLP synthase subunit does not depend on PdxT. Here, we assessed the potential of a B. subtilis ΔpdxT mutant to adapt to PLP limitation at the genome level. The majority of ΔpdxT suppressors had amplified a genomic region containing the pdxS gene. We also identified mutants having acquired as yet undescribed mutations in ammonium assimilation genes, indicating that the overproduction of PdxS and the NrgA ammonium transporter partially relieve vitamin B6 limitation in a ΔpdxT mutant when extracellular ammonium is scarce. Furthermore, we found that PdxS positively affects complex colony formation in B. subtilis. The catalytic mechanism of the PdxS PLP synthase subunit could be the reason for the limited evolution of the enzyme and why we could not identify a PdxS variant producing PLP independently of PdxT at low ammonium concentrations.
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Affiliation(s)
- Björn Richts
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Sabine Lentes
- Department of General Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Anja Poehlein
- Department of Genomic and Applied Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology, Institute for Microbiology and Genetics, University of Goettingen, Göttingen, 37077, Germany
| | - Fabian M Commichau
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
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12
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Buetti-Dinh A, Ruinelli M, Czerski D, Scapozza C, Martignier A, Roman S, Caminada A, Tonolla M. Geochemical and metagenomics study of a metal-rich, green-turquoise-coloured stream in the southern Swiss Alps. PLoS One 2021; 16:e0248877. [PMID: 33784327 PMCID: PMC8009434 DOI: 10.1371/journal.pone.0248877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 03/07/2021] [Indexed: 12/02/2022] Open
Abstract
The Swiss Alpine environments are poorly described from a microbiological perspective. Near the Greina plateau in the Camadra valley in Ticino (southern Swiss Alps), a green-turquoise-coloured water spring streams off the mountain cliffs. Geochemical profiling revealed naturally elevated concentrations of heavy metals such as copper, lithium, zinc and cadmium, which are highly unusual for the geomorphology of the region. Of particular interest, was the presence of a thick biofilm, that was revealed by microscopic analysis to be mainly composed of Cyanobacteria. A metagenome was further assembled to detail the genes found in this environment. A multitude of genes for resistance/tolerance to high heavy metal concentrations were indeed found, such as, various transport systems, and genes involved in the synthesis of extracellular polymeric substances (EPS). EPS have been evoked as a central component in photosynthetic environments rich in heavy metals, for their ability to drive the sequestration of toxic, positively-charged metal ions under high regimes of cyanobacteria-driven photosynthesis. The results of this study provide a geochemical and microbiological description of this unusual environment in the southern Swiss Alps, the role of cyanobacterial photosynthesis in metal resistance, and the potential role of such microbial community in bioremediation of metal-contaminated environments.
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Affiliation(s)
- Antoine Buetti-Dinh
- Laboratory of Applied Microbiology (LMA), Department of Environment, Constructions and Design (DACD), University of Applied Sciences of Southern Switzerland (SUPSI), Bellinzona, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- * E-mail: (ABD); (MT)
| | - Michela Ruinelli
- Laboratory of Applied Microbiology (LMA), Department of Environment, Constructions and Design (DACD), University of Applied Sciences of Southern Switzerland (SUPSI), Bellinzona, Switzerland
| | - Dorota Czerski
- Institute of Earth Sciences, University of Applied Sciences of Southern Switzerland (SUPSI), Trevano, Canobbio, Switzerland
| | - Cristian Scapozza
- Institute of Earth Sciences, University of Applied Sciences of Southern Switzerland (SUPSI), Trevano, Canobbio, Switzerland
| | - Agathe Martignier
- Department of Earth Sciences, University of Geneva, Geneva, Switzerland
| | - Samuele Roman
- Laboratory of Applied Microbiology (LMA), Department of Environment, Constructions and Design (DACD), University of Applied Sciences of Southern Switzerland (SUPSI), Bellinzona, Switzerland
- Alpine Biology Center Foundation, Bellinzona, Switzerland
| | - Annapaola Caminada
- Laboratory of Applied Microbiology (LMA), Department of Environment, Constructions and Design (DACD), University of Applied Sciences of Southern Switzerland (SUPSI), Bellinzona, Switzerland
| | - Mauro Tonolla
- Laboratory of Applied Microbiology (LMA), Department of Environment, Constructions and Design (DACD), University of Applied Sciences of Southern Switzerland (SUPSI), Bellinzona, Switzerland
- Alpine Biology Center Foundation, Bellinzona, Switzerland
- Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
- * E-mail: (ABD); (MT)
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13
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Role of GlnR in Controlling Expression of Nitrogen Metabolism Genes in Listeria monocytogenes. J Bacteriol 2020; 202:JB.00209-20. [PMID: 32690554 DOI: 10.1128/jb.00209-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 07/10/2020] [Indexed: 01/27/2023] Open
Abstract
Listeria monocytogenes is a fastidious bacterial pathogen that can utilize only a limited number of nitrogen sources for growth. Both glutamine and ammonium are common nitrogen sources used in listerial defined growth media, but little is known about the regulation of their uptake or utilization. The functional role of L. monocytogenes GlnR, the transcriptional regulator of nitrogen metabolism genes in low-G+C Gram-positive bacteria, was determined using transcriptome sequencing and real-time reverse transcription-PCR experiments. The GlnR regulon included transcriptional units involved in ammonium transport (amtB glnK) and biosynthesis of glutamine (glnRA) and glutamate (gdhA) from ammonium. As in other bacteria, GlnR proved to be an autoregulatory repressor of the glnRA operon. Unexpectedly, GlnR was most active during growth with ammonium as the nitrogen source and less active in the glutamine medium, apparently because listerial cells perceive growth with glutamine as a nitrogen-limiting condition. Therefore, paradoxically, expression of the glnA gene, encoding glutamine synthetase, was highest in the glutamine medium. For the amtB glnK operon, GlnR served as both a negative regulator in the presence of ammonium and a positive regulator in the glutamine medium. The gdhA gene was subject to a third mode of regulation that apparently required an elevated level of GlnR for repression. Finally, activity of glutamate dehydrogenase encoded by the gdhA gene appeared to correlate inversely with expression of gltAB, the operon that encodes the other major glutamate-synthesizing enzyme, glutamate synthase. Both gdhA and amtB were also regulated, in a negative manner, by the global transcriptional regulator CodY.IMPORTANCE L. monocytogenes is a widespread foodborne pathogen. Nitrogen-containing compounds, such as the glutamate-containing tripeptide, glutathione, and glutamine, have been shown to be important for expression of L. monocytogenes virulence genes. In this work, we showed that a transcriptional regulator, GlnR, controls expression of critical listerial genes of nitrogen metabolism that are involved in ammonium uptake and biosynthesis of glutamine and glutamate. A different mode of GlnR-mediated regulation was found for each of these three pathways.
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14
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Liu G, Vijayaraman SB, Dong Y, Li X, Andongmaa BT, Zhao L, Tu J, He J, Lin L. Bacillus velezensis LG37: transcriptome profiling and functional verification of GlnK and MnrA in ammonia assimilation. BMC Genomics 2020; 21:215. [PMID: 32143571 PMCID: PMC7060608 DOI: 10.1186/s12864-020-6621-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 02/25/2020] [Indexed: 11/14/2022] Open
Abstract
Background In recent years, interest in Bacillus velezensis has increased significantly due to its role in many industrial water bioremediation processes. In this study, we isolated and assessed the transcriptome of Bacillus velezensis LG37 (from an aquaculture pond) under different nitrogen sources. Since Bacillus species exhibit heterogeneity, it is worth investigating the molecular mechanism of LG37 through ammonia nitrogen assimilation, where nitrogen in the form of molecular ammonia is considered toxic to aquatic organisms. Results Here, a total of 812 differentially expressed genes (DEGs) from the transcriptomic sequencing of LG37 grown in minimal medium supplemented with ammonia (treatment) or glutamine (control) were obtained, from which 56 had Fold Change ≥2. BLAST-NCBI and UniProt databases revealed 27 out of the 56 DEGs were potentially involved in NH4+ assimilation. Among them, 8 DEGs together with the two-component regulatory system GlnK/GlnL were randomly selected for validation by quantitative real-time RT-PCR, and the results showed that expression of all the 8 DEGs are consistent with the RNA-seq data. Moreover, the transcriptome and relative expression analysis were consistent with the transporter gene amtB and it is not involved in ammonia transport, even in the highest ammonia concentrations. Besides, CRISPR-Cas9 knockout and overexpression glnK mutants further evidenced the exclusion of amtB regulation, suggesting the involvement of alternative transporter. Additionally, in the transcriptomic data, a novel ammonium transporter mnrA was expressed significantly in increased ammonia concentrations. Subsequently, OEmnrA and ΔmnrA LG37 strains showed unique expression pattern of specific genes compared to that of wild-LG37 strain. Conclusion Based on the transcriptome data, regulation of nitrogen related genes was determined in the newly isolated LG37 strain to analyse the key regulating factors during ammonia assimilation. Using genomics tools, the novel MnrA transporter of LG37 became apparent in ammonia transport instead of AmtB, which transports ammonium nitrogen in other Bacillus strains. Collectively, this study defines heterogeneity of B. velezensis LG37 through comprehensive transcriptome analysis and subsequently, by genome editing techniques, sheds light on the enigmatic mechanisms controlling the functional genes under different nitrogen sources also reveals the need for further research.
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Affiliation(s)
- Guangxin Liu
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China.,Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, Guangdong Provincial Key Laboratory of Waterfowl Healthy Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, Guangdong, China
| | - Sarath Babu Vijayaraman
- Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, Guangdong Provincial Key Laboratory of Waterfowl Healthy Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, Guangdong, China
| | - Yanjun Dong
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Xinfeng Li
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Binda Tembeng Andongmaa
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Lijuan Zhao
- Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, Guangdong Provincial Key Laboratory of Waterfowl Healthy Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, Guangdong, China
| | - Jiagang Tu
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China.
| | - Li Lin
- State Key Laboratory of Agricultural Microbiology, College of Fisheries and College of Life Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China. .,Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, Guangdong Provincial Key Laboratory of Waterfowl Healthy Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, Guangdong, China. .,Laboratory for Marine Fisheries Science and Food Production Processes, National Laboratory for Marine Science and Technology, Qingdao, 266071, Shandong, China.
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15
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Niu T, Lv X, Liu Z, Li J, Du G, Liu L. Synergetic engineering of central carbon and nitrogen metabolism for the production ofN‐acetylglucosamine inBacillus subtilis. Biotechnol Appl Biochem 2020; 67:123-132. [DOI: 10.1002/bab.1845] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 10/23/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Tengfei Niu
- Key Laboratory of Carbohydrate Chemistry and BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
- Key Laboratory of Industrial BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
| | - Xueqin Lv
- Key Laboratory of Carbohydrate Chemistry and BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
- Key Laboratory of Industrial BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
| | - Zhenmin Liu
- State Key Laboratory of Dairy BiotechnologyShanghai Engineering Research Center of Dairy BiotechnologyDairy Research InstituteBright Dairy & Food Co., Ltd. Shanghai People's Republic of China
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
- Key Laboratory of Industrial BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
- Key Laboratory of Industrial BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
- Key Laboratory of Industrial BiotechnologyMinistry of EducationJiangnan University Wuxi People's Republic of China
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16
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Gundlach J, Krüger L, Herzberg C, Turdiev A, Poehlein A, Tascón I, Weiss M, Hertel D, Daniel R, Hänelt I, Lee VT, Stülke J. Sustained sensing in potassium homeostasis: Cyclic di-AMP controls potassium uptake by KimA at the levels of expression and activity. J Biol Chem 2019; 294:9605-9614. [PMID: 31061098 DOI: 10.1074/jbc.ra119.008774] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/01/2019] [Indexed: 12/29/2022] Open
Abstract
The signaling nucleotide cyclic di-AMP (c-di-AMP) is the only known essential second messenger in bacteria. Recently, c-di-AMP has been identified as being essential for controlling potassium uptake in the model organism Bacillus subtilis and several other bacteria. A B. subtilis strain lacking c-di-AMP is not viable at high potassium concentrations, unless the bacteria acquire suppressor mutations. In this study, we isolated such suppressor mutants and found mutations that reduced the activities of the potassium transporters KtrCD and KimA. Although c-di-AMP-mediated control of KtrCD has previously been demonstrated, it is unknown how c-di-AMP affects KimA activity. Using the DRaCALA screening assay, we tested for any interactions of KimA and other potential target proteins in B. subtilis with c-di-AMP. This assay identified KimA, as well as the K+/H+ antiporter KhtT, the potassium exporter CpaA (YjbQ), the osmoprotectant transporter subunit OpuCA, the primary Mg2+ importer MgtE, and DarB (YkuL), a protein of unknown function, as bona fide c-di-AMP-binding proteins. Further, binding of c-di-AMP to KimA inhibited potassium uptake. Our results indicate that c-di-AMP controls KimA-mediated potassium transport at both kimA gene expression and KimA activity levels. Moreover, the discovery that potassium exporters are c-di-AMP targets indicates that this second messenger controls potassium homeostasis in B. subtilis at a global level by binding to riboswitches and to different classes of transport proteins involved in potassium uptake and export.
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Affiliation(s)
- Jan Gundlach
- From the Departments of General Microbiology and
| | | | | | - Asan Turdiev
- the Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742, and
| | - Anja Poehlein
- Genomic and Applied Microbiology, Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, 37077 Göttingen, Germany, and
| | - Igor Tascón
- the Institute of Biochemistry, Goethe University Frankfurt, 60323 Frankfurt, Germany
| | - Martin Weiss
- From the Departments of General Microbiology and
| | - Dietrich Hertel
- the Department of Plant Ecology and Ecosystems Research, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Rolf Daniel
- Genomic and Applied Microbiology, Göttingen Center for Molecular Biosciences, Georg-August-University Göttingen, 37077 Göttingen, Germany, and
| | - Inga Hänelt
- the Institute of Biochemistry, Goethe University Frankfurt, 60323 Frankfurt, Germany
| | - Vincent T Lee
- the Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742, and
| | - Jörg Stülke
- From the Departments of General Microbiology and
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17
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Zhao H, Roistacher DM, Helmann JD. Aspartate deficiency limits peptidoglycan synthesis and sensitizes cells to antibiotics targeting cell wall synthesis in Bacillus subtilis. Mol Microbiol 2018; 109:826-844. [PMID: 29995990 DOI: 10.1111/mmi.14078] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 07/02/2018] [Accepted: 07/05/2018] [Indexed: 12/31/2022]
Abstract
Peptidoglycan synthesis is an important target for antibiotics and relies on intermediates derived from central metabolism. As a result, alterations of metabolism may affect antibiotic sensitivity. An aspB mutant is auxotrophic for aspartate (Asp) and asparagine (Asn) and lyses when grown in Difco sporulation medium (DSM), but not in LB medium. Genetic and physiological studies, supported by amino acid analysis, reveal that cell lysis in DSM results from Asp limitation due to a relatively low Asp and high glutamate (Glu) concentrations, with Glu functioning as a competitive inhibitor of Asp uptake by the major Glu/Asp transporter GltT. Lysis can be specifically suppressed by supplementation with 2,6-diaminopimelate (DAP), which is imported by two different cystine uptake systems. These studies suggest that aspartate limitation depletes the peptidoglycan precursor meso-2,6-diaminopimelate (mDAP), inhibits peptidoglycan synthesis, upregulates the cell envelope stress response mediated by σM and eventually leads to cell lysis. Aspartate limitation sensitizes cells to antibiotics targeting late steps of PG synthesis, but not steps prior to the addition of mDAP into the pentapeptide sidechain. This work highlights the ability of perturbations of central metabolism to sensitize cells to peptidoglycan synthesis inhibitors.
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Affiliation(s)
- Heng Zhao
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | | | - John D Helmann
- Department of Microbiology, Cornell University, Ithaca, NY, USA
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18
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Xu D, Yao H, Cao C, Xu Z, Li S, Xu Z, Zhou J, Feng X, Xu H. Enhancement of ε-poly-l-lysine production by overexpressing the ammonium transporter gene in Streptomyces albulus PD-1. Bioprocess Biosyst Eng 2018; 41:1337-1345. [DOI: 10.1007/s00449-018-1961-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/28/2018] [Indexed: 12/11/2022]
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19
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Zhang JJ, Hu WL, Yang Y, Li H, Picardeau M, Yan J, Yang XF. The sigma factor σ 54 is required for the long-term survival of Leptospira biflexa in water. Mol Microbiol 2018; 109:10.1111/mmi.13967. [PMID: 29633391 PMCID: PMC6174002 DOI: 10.1111/mmi.13967] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2018] [Indexed: 12/21/2022]
Abstract
Leptospira spp. comprise both pathogenic and free-living saprophytic species. Little is known about the environmental adaptation and survival mechanisms of Leptospira. Alternative sigma factor, σ54 (RpoN) is known to play an important role in environmental and host adaptation in many bacteria. In this study, we constructed an rpoN mutant by allele exchange, and the complemented strain in saprophytic L. biflexa. Transcriptome analysis revealed that expression of several genes involved in nitrogen uptake and metabolism, including amtB1, glnB-amtB2, ntrX and narK, were controlled by σ54 . While wild-type L. biflexa could not grow under nitrogen-limiting conditions but was able to survive under such conditions and recover rapidly, the rpoN mutant was not. The rpoN mutant also had dramatically reduced ability to survive long-term in water. σ54 appears to regulate expression of amtB1, glnK-amtB2, ntrX and narK in an indirect manner. However, we identified a novel nitrogen-related gene, LEPBI_I1011, whose expression was directly under the control of σ54 (herein renamed as rcfA for RpoN-controlled factor A). Taken together, our data reveal that the σ54 regulatory network plays an important role in the long-term environmental survival of Leptospira spp.
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Affiliation(s)
- Jun-Jie Zhang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Wei-Lin Hu
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Youyun Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Hongxia Li
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | | | - Jie Yan
- Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - X. Frank Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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20
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Tödter D, Gunka K, Stülke J. The Highly Conserved Asp23 Family Protein YqhY Plays a Role in Lipid Biosynthesis in Bacillus subtilis. Front Microbiol 2017; 8:883. [PMID: 28579978 PMCID: PMC5437119 DOI: 10.3389/fmicb.2017.00883] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 05/02/2017] [Indexed: 01/22/2023] Open
Abstract
In most bacteria, fatty acid biosynthesis is an essential process that must be controlled by the availability of precursors and by the needs of cell division. So far, no mechanisms controlling synthesis of malonyl-coenzyme A (CoA), the committed step in fatty acid synthesis, have been identified in the Gram-positive model bacterium Bacillus subtilis. We have studied the localization and function of two highly expressed proteins of unknown function, YqhY and YloU. Both proteins are members of the conserved and widespread Asp23 family. While the deletion of yloU had no effect, loss of the yqhY gene induced the rapid acquisition of suppressor mutations. The vast majority of these mutations affect subunits of the acetyl-CoA carboxylase (ACCase) complex, the enzyme that catalyzes the formation of malonyl-CoA. Moreover, lack of yqhY is accompanied by the formation of lipophilic clusters in the polar regions of the cells indicating an increased activity of ACCase. Our results suggest that YqhY controls the activity of ACCase and that this control results in inhibition of ACCase activity. Hyperactivity of the enzyme complex in the absence of YqhY does then provoke mutations that cause reduced ACCase activity.
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Affiliation(s)
- Dominik Tödter
- Department of General Microbiology, Institute of Microbiology and Genetics, University of GöttingenGöttingen, Germany
| | - Katrin Gunka
- Department of General Microbiology, Institute of Microbiology and Genetics, University of GöttingenGöttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute of Microbiology and Genetics, University of GöttingenGöttingen, Germany
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21
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Yu W, Chen Z, Ye H, Liu P, Li Z, Wang Y, Li Q, Yan S, Zhong CJ, He N. Effect of glucose on poly-γ-glutamic acid metabolism in Bacillus licheniformis. Microb Cell Fact 2017; 16:22. [PMID: 28178965 PMCID: PMC5299652 DOI: 10.1186/s12934-017-0642-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 01/28/2017] [Indexed: 11/23/2022] Open
Abstract
Background Poly-gamma-glutamic acid (γ-PGA) is a promising macromolecule with potential as a replacement for chemosynthetic polymers. γ-PGA can be produced by many microorganisms, including Bacillus species. Bacillus licheniformis CGMCC2876 secretes γ-PGA when using glycerol and trisodium citrate as its optimal carbon sources and secretes polysaccharides when using glucose as the sole carbon source. To better understand the metabolic mechanism underlying the secretion of polymeric substances, SWATH was applied to investigate the effect of glucose on the production of polysaccharides and γ-PGA at the proteome level. Results The addition of glucose at 5 or 10 g/L of glucose decreased the γ-PGA concentration by 31.54 or 61.62%, respectively, whereas the polysaccharide concentration increased from 5.2 to 43.47%. Several proteins playing related roles in γ-PGA and polysaccharide synthesis were identified using the SWATH acquisition LC–MS/MS method. CcpA and CcpN co-enhanced glycolysis and suppressed carbon flux into the TCA cycle, consequently slowing glutamic acid synthesis. On the other hand, CcpN cut off the carbon flux from glycerol metabolism and further reduced γ-PGA production. CcpA activated a series of operons (glm and epsA-O) to reallocate the carbon flux to polysaccharide synthesis when glucose was present. The production of γ-PGA was influenced by NrgB, which converted the major nitrogen metabolic flux between NH4+ and glutamate. Conclusion The mechanism by which B. licheniformis regulates two macromolecules was proposed for the first time in this paper. This genetic information will facilitate the engineering of bacteria for practicable strategies for the fermentation of γ-PGA and polysaccharides for diverse applications. Electronic supplementary material The online version of this article (doi:10.1186/s12934-017-0642-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Wencheng Yu
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.,The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Zhen Chen
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.,The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Hong Ye
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.,The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Peize Liu
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.,The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Zhipeng Li
- Fujian Provincial Key Laboratory of Fire Retardant Materials, College of Materials, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Yuanpeng Wang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.,The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Qingbiao Li
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.,The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China
| | - Shan Yan
- Department of Chemistry, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Chuan-Jian Zhong
- Department of Chemistry, State University of New York at Binghamton, Binghamton, NY, 13902, USA
| | - Ning He
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China. .,The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China.
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22
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Rudakova NL, Sabirova AR, Balaban NP, Tikhonova AO, Sharipova MR. Features of Gene Expression of Bacillus pumilus Metalloendopeptidase. BIOCHEMISTRY. BIOKHIMIIA 2016; 81:884-891. [PMID: 27677556 DOI: 10.1134/s0006297916080095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Features of gene expression of the secreted Bacillus pumilus metalloendopeptidase belonging to the adamalysin/reprolysin family were investigated. In the regulatory region of the gene, we identified hypothetical binding sites for transcription factors CcpA and TnrA. We found that the expression of the metalloendopeptidase gene is controlled by mechanisms of carbon and nitrogen catabolite repression. In experiments involving nitrogen metabolism regulatory protein mutant strains, we found that the control of the metalloendopeptidase gene expression involves proteins of ammonium transport GlnK and AmtB interacting with the TnrA-regulator.
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Affiliation(s)
- N L Rudakova
- Kazan (Volga Region) Federal University, Kazan, 420008, Russia.
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23
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Kröber M, Verwaaijen B, Wibberg D, Winkler A, Pühler A, Schlüter A. Comparative transcriptome analysis of the biocontrol strain Bacillus amyloliquefaciens FZB42 as response to biofilm formation analyzed by RNA sequencing. J Biotechnol 2016; 231:212-223. [PMID: 27312701 DOI: 10.1016/j.jbiotec.2016.06.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 05/23/2016] [Accepted: 06/12/2016] [Indexed: 10/21/2022]
Abstract
The strain Bacillus amyloliquefaciens FZB42 is a plant growth promoting rhizobacterium (PGPR) and biocontrol agent known to keep infections of lettuce (Lactuca sativa) by the phytopathogen Rhizoctonia solani down. Several mechanisms, including the production of secondary metabolites possessing antimicrobial properties and induction of the host plant's systemic resistance (ISR), were proposed to explain the biocontrol effect of the strain. B. amyloliquefaciens FZB42 is able to form plaques (biofilm-like structures) on plant roots and this feature was discussed to be associated with its biocontrol properties. For this reason, formation of B. amyloliquefaciens biofilms was studied at the transcriptional level using high-throughput sequencing of whole transcriptome cDNA libraries from cells grown under biofilm-forming conditions vs. planktonic growth. Comparison of the transcriptional profiles of B. amyloliquefaciens FZB42 under these growth conditions revealed a common set of highly transcribed genes mostly associated with basic cellular functions. The lci gene, encoding an antimicrobial peptide (AMP), was among the most highly transcribed genes of cells under both growth conditions suggesting that AMP production may contribute to biocontrol. In contrast, gene clusters coding for synthesis of secondary metabolites with antimicrobial properties were only moderately transcribed and not induced in biofilm-forming cells. Differential gene expression revealed that 331 genes were significantly up-regulated and 230 genes were down-regulated in the transcriptome of B. amyloliquefaciens FZB42 under biofilm-forming conditions in comparison to planktonic cells. Among the most highly up-regulated genes, the yvqHI operon, coding for products involved in nisin (class I bacteriocin) resistance, was identified. In addition, an operon whose products play a role in fructosamine metabolism was enhanced in its transcription. Moreover, genes involved in the production of the extracellular biofilm matrix including exopolysaccharide genes (eps) and the yqxM-tasA-sipW operon encoding amyloid fiber synthesis were up-regulated in the B. amyloliquefaciens FZB42 biofilm. On the other hand, highly down-regulated genes in biofilms are associated with synthesis, assembly and regulation of the flagellar apparatus, the degradation of aromatic compounds and the export of copper. The obtained transcriptional profile for B. amyloliquefaciens biofilm cells uncovered genes involved in its development and enabled the assessment that synthesis of secondary metabolites among other factors may contribute to the biocontrol properties of the strain.
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Affiliation(s)
- Magdalena Kröber
- Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Bart Verwaaijen
- Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Daniel Wibberg
- Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Anika Winkler
- Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Alfred Pühler
- Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Andreas Schlüter
- Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Bielefeld, Germany.
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24
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Hauf K, Kayumov A, Gloge F, Forchhammer K. The Molecular Basis of TnrA Control by Glutamine Synthetase in Bacillus subtilis. J Biol Chem 2015; 291:3483-95. [PMID: 26635369 DOI: 10.1074/jbc.m115.680991] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Indexed: 12/16/2022] Open
Abstract
TnrA is a master regulator of nitrogen assimilation in Bacillus subtilis. This study focuses on the mechanism of how glutamine synthetase (GS) inhibits TnrA function in response to key metabolites ATP, AMP, glutamine, and glutamate. We suggest a model of two mutually exclusive GS conformations governing the interaction with TnrA. In the ATP-bound state (A-state), GS is catalytically active but unable to interact with TnrA. This conformation was stabilized by phosphorylated L-methionine sulfoximine (MSX), fixing the enzyme in the transition state. When occupied by glutamine (or its analogue MSX), GS resides in a conformation that has high affinity for TnrA (Q-state). The A- and Q-state are mutually exclusive, and in agreement, ATP and glutamine bind to GS in a competitive manner. At elevated concentrations of glutamine, ATP is no longer able to bind GS and to bring it into the A-state. AMP efficiently competes with ATP and prevents formation of the A-state, thereby favoring GS-TnrA interaction. Surface plasmon resonance analysis shows that TnrA bound to a positively regulated promoter fragment binds GS in the Q-state, whereas it rapidly dissociates from a negatively regulated promoter fragment. These data imply that GS controls TnrA activity at positively controlled promoters by shielding the transcription factor in the DNA-bound state. According to size exclusion and multiangle light scattering analysis, the dodecameric GS can bind three TnrA dimers. The highly interdependent ligand binding properties of GS reveal this enzyme as a sophisticated sensor of the nitrogen and energy state of the cell to control the activity of DNA-bound TnrA.
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Affiliation(s)
- Ksenia Hauf
- From the Interfaculty Institute for Microbiology and Infection Medicine, University of Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany
| | - Airat Kayumov
- the Department of Genetics, Kazan Federal University, Kremlevskaya 18, 420008, Kazan, Russia, and
| | - Felix Gloge
- Wyatt Technology Europe, Hochstrasse 12a, 56307 Dernbach, Germany
| | - Karl Forchhammer
- From the Interfaculty Institute for Microbiology and Infection Medicine, University of Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany,
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25
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An Essential Poison: Synthesis and Degradation of Cyclic Di-AMP in Bacillus subtilis. J Bacteriol 2015; 197:3265-74. [PMID: 26240071 DOI: 10.1128/jb.00564-15] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 07/29/2015] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Gram-positive bacteria synthesize the second messenger cyclic di-AMP (c-di-AMP) to control cell wall and potassium homeostasis and to secure the integrity of their DNA. In the firmicutes, c-di-AMP is essential for growth. The model organism Bacillus subtilis encodes three diadenylate cyclases and two potential phosphodiesterases to produce and degrade c-di-AMP, respectively. Among the three cyclases, CdaA is conserved in nearly all firmicutes, and this enzyme seems to be responsible for the c-di-AMP that is required for cell wall homeostasis. Here, we demonstrate that CdaA localizes to the membrane and forms a complex with the regulatory protein CdaR and the glucosamine-6-phosphate mutase GlmM. Interestingly, cdaA, cdaR, and glmM form a gene cluster that is conserved throughout the firmicutes. This conserved arrangement and the observed interaction between the three proteins suggest a functional relationship. Our data suggest that GlmM and GlmS are involved in the control of c-di-AMP synthesis. These enzymes convert glutamine and fructose-6-phosphate to glutamate and glucosamine-1-phosphate. c-di-AMP synthesis is enhanced if the cells are grown in the presence of glutamate compared to that in glutamine-grown cells. Thus, the quality of the nitrogen source is an important signal for c-di-AMP production. In the analysis of c-di-AMP-degrading phosphodiesterases, we observed that both phosphodiesterases, GdpP and PgpH (previously known as YqfF), contribute to the degradation of the second messenger. Accumulation of c-di-AMP in a gdpP pgpH double mutant is toxic for the cells, and the cells respond to this accumulation by inactivation of the diadenylate cyclase CdaA. IMPORTANCE Bacteria use second messengers for signal transduction. Cyclic di-AMP (c-di-AMP) is the only second messenger known so far that is essential for a large group of bacteria. We have studied the regulation of c-di-AMP synthesis and the role of the phosphodiesterases that degrade this second messenger. c-di-AMP synthesis strongly depends on the nitrogen source: glutamate-grown cells produce more c-di-AMP than glutamine-grown cells. The accumulation of c-di-AMP in a strain lacking both phosphodiesterases is toxic and results in inactivation of the diadenylate cyclase CdaA. Our results suggest that CdaA is the critical diadenylate cyclase that produces the c-di-AMP that is both essential and toxic upon accumulation.
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26
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Abstract
Cells that reside within a community can cooperate and also compete with each other for resources. It remains unclear how these opposing interactions are resolved at the population level. Here we investigate such an internal conflict within a microbial (Bacillus subtilis) biofilm community: cells in the biofilm periphery not only protect interior cells from external attack but also starve them through nutrient consumption. We discover that this conflict between protection and starvation is resolved through emergence of long-range metabolic co-dependence between peripheral and interior cells. As a result, biofilm growth halts periodically, increasing nutrient availability for the sheltered interior cells. We show that this collective oscillation in biofilm growth benefits the community in the event of a chemical attack. These findings indicate that oscillations support population-level conflict resolution by coordinating competing metabolic demands in space and time, suggesting new strategies to control biofilm growth.
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27
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Müller B, Manzoor S, Niazi A, Bongcam-Rudloff E, Schnürer A. Genome-guided analysis of physiological capacities of Tepidanaerobacter acetatoxydans provides insights into environmental adaptations and syntrophic acetate oxidation. PLoS One 2015; 10:e0121237. [PMID: 25811859 PMCID: PMC4374699 DOI: 10.1371/journal.pone.0121237] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/30/2015] [Indexed: 11/21/2022] Open
Abstract
This paper describes the genome-based analysis of Tepidanaerobacter acetatoxydans strain Re1, a syntrophic acetate-oxidising bacterium (SAOB). Principal issues such as environmental adaptations, metabolic capacities, and energy conserving systems have been investigated and the potential consequences for syntrophic acetate oxidation discussed. Briefly, in pure culture, T. acetatoxydans grows with different organic compounds and produces acetate as the main product. In a syntrophic consortium with a hydrogenotrophic methanogen, it can also reverse its metabolism and instead convert acetate to formate/H2 and CO2. It can only proceed if the product formed is continuously removed. This process generates a very small amount of energy that is scarcely enough for growth, which makes this particular syntrophy of special interest. As a crucial member of the biogas-producing community in ammonium-rich engineered AD processes, genomic features conferring ammonium resistance, bacterial defense, oxygen and temperature tolerance were found, as well as attributes related to biofilm formation and flocculation. It is likely that T. acetatoxydans can form an electrochemical gradient by putative electron-bifurcating Rnf complex and [Fe-Fe] hydrogenases, as observed in other acetogens. However, genomic deficiencies related to acetogenic metabolism and anaerobic respiration were discovered, such as the lack of formate dehydrogenase and F1F0 ATP synthase. This has potential consequences for the metabolic pathways used under SAO and non-SAO conditions. The two complete sets of bacteriophage genomes, which were found to be encoded in the genome, are also worthy of mention.
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Affiliation(s)
- Bettina Müller
- Department of Microbiology, Swedish University of Agricultural Sciences, BioCenter, Uppsala, Sweden
- * E-mail:
| | - Shahid Manzoor
- Department of Animal Breeding and Genetics Science, Swedish University of Agricultural Science, SLU-Global Bioinformatics Centre, Uppsala, Sweden
- University of the Punjab, Lahore, Pakistan
| | - Adnan Niazi
- Department of Animal Breeding and Genetics Science, Swedish University of Agricultural Science, SLU-Global Bioinformatics Centre, Uppsala, Sweden
| | - Erik Bongcam-Rudloff
- Department of Animal Breeding and Genetics Science, Swedish University of Agricultural Science, SLU-Global Bioinformatics Centre, Uppsala, Sweden
| | - Anna Schnürer
- Department of Microbiology, Swedish University of Agricultural Sciences, BioCenter, Uppsala, Sweden
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28
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Chatterjee J, Giri S, Maity S, Sinha A, Ranjan A, Rajshekhar , Gupta S. Production and characterization of thermostable alkaline protease ofBacillus subtilis(ATCC 6633) from optimized solid-state fermentation. Biotechnol Appl Biochem 2015; 62:709-18. [DOI: 10.1002/bab.1309] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 10/13/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Joyee Chatterjee
- Department of Biotechnology; Haldia Institute of Technology, HIT Campus; Purba Medinipur India
| | - Sudipta Giri
- Department of Biotechnology; Haldia Institute of Technology, HIT Campus; Purba Medinipur India
| | - Sujan Maity
- Department of Biotechnology; Haldia Institute of Technology, HIT Campus; Purba Medinipur India
| | - Ankan Sinha
- Department of Biotechnology; Haldia Institute of Technology, HIT Campus; Purba Medinipur India
| | - Ashish Ranjan
- Department of Biotechnology; Haldia Institute of Technology, HIT Campus; Purba Medinipur India
| | - Rajshekhar
- Department of Biotechnology; Haldia Institute of Technology, HIT Campus; Purba Medinipur India
| | - Suvroma Gupta
- Department of Biotechnology; Haldia Institute of Technology, HIT Campus; Purba Medinipur India
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29
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Inhibition of biofilm formation in Bacillus subtilis by new halogenated furanones. J Antibiot (Tokyo) 2014; 68:297-301. [PMID: 25335695 DOI: 10.1038/ja.2014.143] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 08/12/2014] [Accepted: 09/16/2014] [Indexed: 12/26/2022]
Abstract
Gram-positive bacteria can cause various infections including hospital-acquired infections. While in the biofilm, the resistance of bacteria to both antibiotics and the human immune system is increased causing difficulties in the treatment. Bacillus subtilis, a non-pathogenic Gram-positive bacterium, is widely used as a model organism for studying biofilm formation. Here we investigated the effect of novel synthesized chloro- and bromo-containing 2(5H)-furanones on biofilm formation by B. subtilis. Mucobromic acid (3,4-dibromo-5-hydroxy-2(5H)-furanone) and the two derivatives of mucochloric acid (3,4-dichloro-5-hydroxy-2(5H)-furanone)-F8 and F12-were found to inhibit the growth and to efficiently prevent biofilm formation by B. subtilis. Along with the low production of polysaccharide matrix and repression of the eps operon, strong repression of biofilm-related yqxM also occurred in the presence of furanones. Therefore, our data confirm that furanones affect significantly the regulatory pathway(s) leading to biofilm formation. We propose that the global regulator, Spo0A, is one of the potential putative cellular targets for these compounds.
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30
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Ardin AC, Fujita K, Nagayama K, Takashima Y, Nomura R, Nakano K, Ooshima T, Matsumoto-Nakano M. Identification and functional analysis of an ammonium transporter in Streptococcus mutans. PLoS One 2014; 9:e107569. [PMID: 25229891 PMCID: PMC4167856 DOI: 10.1371/journal.pone.0107569] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 08/13/2014] [Indexed: 12/26/2022] Open
Abstract
Streptococcus mutans, a Gram-positive bacterium, is considered to be a major etiologic agent of human dental caries and reported to form biofilms known as dental plaque on tooth surfaces. This organism is also known to possess a large number of transport proteins in the cell membrane for export and import of molecules. Nitrogen is an essential nutrient for Gram-positive bacteria, though alternative sources such as ammonium can also be utilized. In order to obtain nitrogen for macromolecular synthesis, nitrogen-containing compounds must be transported into the cell. However, the ammonium transporter in S. mutans remains to be characterized. The present study focused on characterizing the ammonium transporter gene of S. mutans and its operon, while related regulatory genes were also analyzed. The SMU.1658 gene corresponding to nrgA in S. mutans is homologous to the ammonium transporter gene in Bacillus subtilis and SMU.1657, located upstream of the nrgA gene and predicted to be glnB, is a member of the PII protein family. Using a nrgA-deficient mutant strain (NRGD), we examined bacterial growth in the presence of ammonium, calcium chloride, and manganese sulfate. Fluorescent efflux assays were also performed to reveal export molecules associated with the ammonium transporter. The growth rate of NRGD was lower, while its fluorescent intensity was much higher as compared to the parental strain. In addition, confocal laser scanning microscopy revealed that the structure of biofilms formed by NRGD was drastically different than that of the parental strain. Furthermore, transcriptional analysis showed that the nrgA gene was co-transcribed with the glnB gene. These results suggest that the nrgA gene in S. mutans is essential for export of molecules and biofilm formation.
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Affiliation(s)
- Arifah Chieko Ardin
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Kazuyo Fujita
- Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kayoko Nagayama
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Yukiko Takashima
- Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Ryota Nomura
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Kazuhiko Nakano
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Takashi Ooshima
- Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Michiyo Matsumoto-Nakano
- Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
- * E-mail:
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31
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Gao T, Ho KP. l-Lactic acid production by Bacillus subtilis MUR1 in continuous culture. J Biotechnol 2013; 168:646-51. [DOI: 10.1016/j.jbiotec.2013.09.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/03/2013] [Accepted: 09/27/2013] [Indexed: 11/25/2022]
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Pedro-Roig L, Lange C, Bonete MJ, Soppa J, Maupin-Furlow J. Nitrogen regulation of protein-protein interactions and transcript levels of GlnK PII regulator and AmtB ammonium transporter homologs in Archaea. Microbiologyopen 2013; 2:826-40. [PMID: 24039236 PMCID: PMC3831643 DOI: 10.1002/mbo3.120] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 07/03/2013] [Accepted: 07/12/2013] [Indexed: 11/08/2022] Open
Abstract
Gene homologs of GlnK PII regulators and AmtB-type ammonium transporters are often paired on prokaryotic genomes, suggesting these proteins share an ancient functional relationship. Here, we demonstrate for the first time in Archaea that GlnK associates with AmtB in membrane fractions after ammonium shock, thus, providing a further insight into GlnK-AmtB as an ancient nitrogen sensor pair. For this work, Haloferax mediterranei was advanced for study through the generation of a pyrE2-based counterselection system that was used for targeted gene deletion and expression of Flag-tagged proteins from their native promoters. AmtB1-Flag was detected in membrane fractions of cells grown on nitrate and was found to coimmunoprecipitate with GlnK after ammonium shock. Thus, in analogy to bacteria, the archaeal GlnK PII may block the AmtB1 ammonium transporter under nitrogen-rich conditions. In addition to this regulated protein-protein interaction, the archaeal amtB-glnK gene pairs were found to be highly regulated by nitrogen availability with transcript levels high under conditions of nitrogen limitation and low during nitrogen excess. While transcript levels of glnK-amtB are similarly regulated by nitrogen availability in bacteria, transcriptional regulators of the bacterial glnK promoter including activation by the two-component signal transduction proteins NtrC (GlnG, NRI) and NtrB (GlnL, NRII) and sigma factor σ(N) (σ(54) ) are not conserved in archaea suggesting a novel mechanism of transcriptional control.
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Affiliation(s)
- Laia Pedro-Roig
- Departamento de Agroquímica y Bioquímica, Facultad de Ciencias, Universidad de Alicante, carretera de San Vicente s/n, 03080, Alicante, Spain
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33
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Bauer S, Endres M, Lange M, Schmidt T, Schumbrutzki C, Sickmann A, Beier D. Novel function assignment to a member of the essential HP1043 response regulator family of epsilon-proteobacteria. Microbiology (Reading) 2013; 159:880-889. [DOI: 10.1099/mic.0.066548-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Susanne Bauer
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Michelle Endres
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Manuel Lange
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Theresa Schmidt
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Cornelia Schumbrutzki
- Leibnitz-Institut für Analytische Wissenschaften – ISAS – e.V., Otto-Hahn-Str. 6B, D-44227 Dortmund, Germany
| | - Albert Sickmann
- Leibnitz-Institut für Analytische Wissenschaften – ISAS – e.V., Otto-Hahn-Str. 6B, D-44227 Dortmund, Germany
| | - Dagmar Beier
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
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Fedorova K, Kayumov A, Woyda K, Ilinskaja O, Forchhammer K. Transcription factor TnrA inhibits the biosynthetic activity of glutamine synthetase in Bacillus subtilis. FEBS Lett 2013; 587:1293-8. [PMID: 23535029 DOI: 10.1016/j.febslet.2013.03.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Revised: 03/11/2013] [Accepted: 03/11/2013] [Indexed: 11/25/2022]
Abstract
The Bacillus subtilis glutamine synthetase (GS) plays a dual role in cell metabolism by functioning as catalyst and regulator. GS catalyses the ATP-dependent synthesis of glutamine from glutamate and ammonium. Under nitrogen-rich conditions, GS becomes feedback-inhibited by high intracellular glutamine levels and then binds transcription factors GlnR and TnrA, which control the genes of nitrogen assimilation. While GS-bound TnrA is no longer able to interact with DNA, GlnR-DNA binding is shown to be stimulated by GS complex formation. In this paper we show a new physiological feature of the interaction between glutamine synthetase and TnrA. The transcription factor TnrA inhibits the biosynthetic activity of glutamine synthetase in vivo and in vitro, while the GlnR protein does not affect the activity of the enzyme.
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Affiliation(s)
- Ksenia Fedorova
- Kazan (Volga region) Federal University, Department of Microbiology, Kremlevskaya 18, 420008 Kazan, Russia
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35
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Huergo LF, Chandra G, Merrick M. PIIsignal transduction proteins: nitrogen regulation and beyond. FEMS Microbiol Rev 2013; 37:251-83. [DOI: 10.1111/j.1574-6976.2012.00351.x] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 07/26/2012] [Accepted: 07/26/2012] [Indexed: 01/12/2023] Open
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36
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MUTANT STRAIN of Bacillus subtilis IFBG MC-1 WITH INCREASED TRYPTOPHAN SYNTHESIS. BIOTECHNOLOGIA ACTA 2013. [DOI: 10.15407/biotech6.06.105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Gunka K, Commichau FM. Control of glutamate homeostasis in Bacillus subtilis: a complex interplay between ammonium assimilation, glutamate biosynthesis and degradation. Mol Microbiol 2012; 85:213-24. [DOI: 10.1111/j.1365-2958.2012.08105.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Groot Kormelink T, Koenders E, Hagemeijer Y, Overmars L, Siezen RJ, de Vos WM, Francke C. Comparative genome analysis of central nitrogen metabolism and its control by GlnR in the class Bacilli. BMC Genomics 2012; 13:191. [PMID: 22607086 PMCID: PMC3412718 DOI: 10.1186/1471-2164-13-191] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 03/20/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The assimilation of nitrogen in bacteria is achieved through only a few metabolic conversions between alpha-ketoglutarate, glutamate and glutamine. The enzymes that catalyze these conversions are glutamine synthetase, glutaminase, glutamate dehydrogenase and glutamine alpha-ketoglutarate aminotransferase. In low-GC Gram-positive bacteria the transcriptional control over the levels of the related enzymes is mediated by four regulators: GlnR, TnrA, GltC and CodY. We have analyzed the genomes of all species belonging to the taxonomic families Bacillaceae, Listeriaceae, Staphylococcaceae, Lactobacillaceae, Leuconostocaceae and Streptococcaceae to determine the diversity in central nitrogen metabolism and reconstructed the regulation by GlnR. RESULTS Although we observed a substantial difference in the extent of central nitrogen metabolism in the various species, the basic GlnR regulon was remarkably constant and appeared not affected by the presence or absence of the other three main regulators. We found a conserved regulatory association of GlnR with glutamine synthetase (glnRA operon), and the transport of ammonium (amtB-glnK) and glutamine/glutamate (i.e. via glnQHMP, glnPHQ, gltT, alsT). In addition less-conserved associations were found with, for instance, glutamate dehydrogenase in Streptococcaceae, purine catabolism and the reduction of nitrite in Bacillaceae, and aspartate/asparagine deamination in Lactobacillaceae. CONCLUSIONS Our analyses imply GlnR-mediated regulation in constraining the import of ammonia/amino-containing compounds and the production of intracellular ammonia under conditions of high nitrogen availability. Such a role fits with the intrinsic need for tight control of ammonia levels to limit futile cycling.
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Affiliation(s)
- Tom Groot Kormelink
- Kluyver Centre for Genomics of Industrial Fermentation, Delft, The Netherlands
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Sarkar A, Köhler J, Hurek T, Reinhold-Hurek B. A novel regulatory role of the Rnf complex of Azoarcus sp. strain BH72. Mol Microbiol 2011; 83:408-22. [DOI: 10.1111/j.1365-2958.2011.07940.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kayumov A, Heinrich A, Fedorova K, Ilinskaya O, Forchhammer K. Interaction of the general transcription factor TnrA with the PII-like protein GlnK and glutamine synthetase in Bacillus subtilis. FEBS J 2011; 278:1779-89. [DOI: 10.1111/j.1742-4658.2011.08102.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kayumov AR, Fedorova KP, Il’inskaya ON, Sharipova MR. Content and localization of TNRA and GLNK regulatory proteins in the cells of Bacillus subtilis under nitrogen starvation. Mol Biol 2010. [DOI: 10.1134/s0026893310040229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Gunka K, Newman JA, Commichau FM, Herzberg C, Rodrigues C, Hewitt L, Lewis RJ, Stülke J. Functional dissection of a trigger enzyme: mutations of the bacillus subtilis glutamate dehydrogenase RocG that affect differentially its catalytic activity and regulatory properties. J Mol Biol 2010; 400:815-27. [PMID: 20630473 DOI: 10.1016/j.jmb.2010.05.055] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 05/20/2010] [Accepted: 05/22/2010] [Indexed: 11/12/2022]
Abstract
Any signal transduction requires communication between a sensory component and an effector. Some enzymes engage in signal perception and transduction, as well as in catalysis, and these proteins are known as "trigger" enzymes. In this report, we detail the trigger properties of RocG, the glutamate dehydrogenase of Bacillus subtilis. RocG not only deaminates the key metabolite glutamate to form alpha-ketoglutarate but also interacts directly with GltC, a LysR-type transcription factor that regulates glutamate biosynthesis from alpha-ketoglutarate, thus linking the two metabolic pathways. We have isolated mutants of RocG that separate the two functions. Several mutations resulted in permanent inactivation of GltC as long as a source of glutamate was present. These RocG proteins have lost their ability to catabolize glutamate due to a strongly reduced affinity for glutamate. The second class of mutants is exemplified by the replacement of aspartate residue 122 by asparagine. This mutant protein has retained enzymatic activity but has lost the ability to control the activity of GltC. Crystal structures of glutamate dehydrogenases that permit a molecular explanation of the properties of the various mutants are presented. Specifically, we may propose that D122N replacement affects the surface of RocG. Our data provide evidence for a correlation between the enzymatic activity of RocG and its ability to inactivate GltC, and thus give insights into the mechanism that couples the enzymatic activity of a trigger enzyme to its regulatory function.
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Affiliation(s)
- Katrin Gunka
- Abteilung für Allgemeine Mikrobiologie, Institut für Mikrobiologie und Genetik, Georg-August-Universität Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany
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Amon J, Titgemeyer F, Burkovski A. Common patterns - unique features: nitrogen metabolism and regulation in Gram-positive bacteria. FEMS Microbiol Rev 2010; 34:588-605. [PMID: 20337720 DOI: 10.1111/j.1574-6976.2010.00216.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Gram-positive bacteria have developed elaborate mechanisms to control ammonium assimilation, at the levels of both transcription and enzyme activity. In this review, the common and specific mechanisms of nitrogen assimilation and regulation in Gram-positive bacteria are summarized and compared for the genera Bacillus, Clostridium, Streptomyces, Mycobacterium and Corynebacterium, with emphasis on the high G+C genera. Furthermore, the importance of nitrogen metabolism and control for the pathogenic lifestyle and virulence is discussed. In summary, the regulation of nitrogen metabolism in prokaryotes shows an impressive diversity. Virtually every phylum of bacteria evolved its own strategy to react to the changing conditions of nitrogen supply. Not only do the transcription factors differ between the phyla and sometimes even between families, but the genetic targets of a given regulon can also differ between closely related species.
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Affiliation(s)
- Johannes Amon
- Lehrstuhl für Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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Kayumov AR, Shamsutdinov TR, Sabirova AR, Sharipova MR. Effect of the regulation system of metabolic nitrogen exchange on biosynthesis of serine proteinases from Bacillus intermedius. Microbiology (Reading) 2009. [DOI: 10.1134/s0026261709060046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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46
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Kharitonova MA, Vershinina VI. Biosynthesis of secreted ribonucleases of Bacillus intermedius and Bacillus circulans under nitrogen starvation. Microbiology (Reading) 2009. [DOI: 10.1134/s0026261709020088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Kayumov A, Heinrich A, Sharipova M, Iljinskaya O, Forchhammer K. Inactivation of the general transcription factor TnrA in Bacillus subtilis by proteolysis. MICROBIOLOGY-SGM 2008; 154:2348-2355. [PMID: 18667567 DOI: 10.1099/mic.0.2008/019802-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Under conditions of nitrogen limitation, the general transcription factor TnrA in Bacillus subtilis activates the expression of genes involved in assimilation of various nitrogen sources. Previously, TnrA activity has been shown to be controlled by protein-protein interaction with glutamine synthetase, the key enzyme of ammonia assimilation. Furthermore, depending on ATP and 2-oxoglutarate levels, TnrA can bind to the GlnK-AmtB complex. Here, we report that upon transfer of nitrate-grown cells to combined nitrogen-depleted medium, TnrA is rapidly eliminated from the cells by proteolysis. As long as TnrA is membrane-bound through GlnK-AmtB interaction it seems to be protected from degradation. Upon removal of nitrogen sources, the localization of TnrA becomes cytosolic and degradation occurs. The proteolytic activity against TnrA was detected in the cytosolic fraction but not in the membrane, and its presence does not depend on the nitrogen regime of cell growth. The proteolytic degradation of TnrA as a response to complete nitrogen starvation might represent a novel mechanism of TnrA control in B. subtilis.
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Affiliation(s)
- Airat Kayumov
- Department of Microbiology, Kazan State University, Kremlevskaya 18, 420008 Kazan, Russia
| | - Annette Heinrich
- Institut für Mikrobiologie, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 28, D-72076 Tübingen, Germany
| | - Margarita Sharipova
- Department of Microbiology, Kazan State University, Kremlevskaya 18, 420008 Kazan, Russia
| | - Olga Iljinskaya
- Department of Microbiology, Kazan State University, Kremlevskaya 18, 420008 Kazan, Russia
| | - Karl Forchhammer
- Institut für Mikrobiologie, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 28, D-72076 Tübingen, Germany
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Glutamate metabolism in Bacillus subtilis: gene expression and enzyme activities evolved to avoid futile cycles and to allow rapid responses to perturbations of the system. J Bacteriol 2008; 190:3557-64. [PMID: 18326565 DOI: 10.1128/jb.00099-08] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Glutamate is a central metabolite in all organisms since it provides the link between carbon and nitrogen metabolism. In Bacillus subtilis, glutamate is synthesized exclusively by the glutamate synthase, and it can be degraded by the glutamate dehydrogenase. In B. subtilis, the major glutamate dehydrogenase RocG is expressed only in the presence of arginine, and the bacteria are unable to utilize glutamate as the only carbon source. In addition to rocG, a second cryptic gene (gudB) encodes an inactive glutamate dehydrogenase. Mutations in rocG result in the rapid accumulation of gudB1 suppressor mutations that code for an active enzyme. In this work, we analyzed the physiological significance of this constellation of genes and enzymes involved in glutamate metabolism. We found that the weak expression of rocG in the absence of the inducer arginine is limiting for glutamate utilization. Moreover, we addressed the potential ability of the active glutamate dehydrogenases of B. subtilis to synthesize glutamate. Both RocG and GudB1 were unable to catalyze the anabolic reaction, most probably because of their very high K(m) values for ammonium. In contrast, the Escherichia coli glutamate dehydrogenase is able to produce glutamate even in the background of a B. subtilis cell. B. subtilis responds to any mutation that interferes with glutamate metabolism with the rapid accumulation of extragenic or intragenic suppressor mutations, bringing the glutamate supply into balance. Similarly, with the presence of a cryptic gene, the system can flexibly respond to changes in the external glutamate supply by the selection of mutations.
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Tiffert Y, Supra P, Wurm R, Wohlleben W, Wagner R, Reuther J. The Streptomyces coelicolor GlnR regulon: identification of new GlnR targets and evidence for a central role of GlnR in nitrogen metabolism in actinomycetes. Mol Microbiol 2008; 67:861-80. [PMID: 18179599 DOI: 10.1111/j.1365-2958.2007.06092.x] [Citation(s) in RCA: 150] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Streptomyces coelicolor GlnR is a global regulator that controls genes involved in nitrogen metabolism. By genomic screening 10 new GlnR targets were identified, including enzymes for ammonium assimilation (glnII, gdhA), nitrite reduction (nirB), urea cleavage (ureA) and a number of biochemically uncharacterized proteins (SCO0255, SCO0888, SCO2195, SCO2400, SCO2404, SCO7155). For the GlnR regulon, a GlnR binding site which comprises the sequence gTnAc-n(6)-GaAAc-n(6)-GtnAC-n(6)-GAAAc-n(6) has been found. Reverse transcription analysis of S. coelicolor and the S. coelicolor glnR mutant revealed that GlnR activates or represses the expression of its target genes. Furthermore, glnR expression itself was shown to be nitrogen-dependent. Physiological studies of S. coelicolor and the S. coelicolor glnR mutant with ammonium and nitrate as the sole nitrogen source revealed that GlnR is not only involved in ammonium assimilation but also in ammonium supply. blast analysis demonstrated that GlnR-homologous proteins are present in different actinomycetes containing the glnA gene with the conserved GlnR binding site. By DNA binding studies, it was furthermore demonstrated that S. coelicolor GlnR is able to interact with these glnA upstream regions. We therefore suggest that GlnR-mediated regulation is not restricted to Streptomyces but constitutes a regulon conserved in many actinomycetes.
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Affiliation(s)
- Yvonne Tiffert
- Mikrobiologie/Biotechnologie, Institut für Mikrobiologie, Fakultät für Biologie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, D-72076 Tübingen, Germany
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Huergo LF, Merrick M, Pedrosa FO, Chubatsu LS, Araujo LM, Souza EM. Ternary complex formation between AmtB, GlnZ and the nitrogenase regulatory enzyme DraG reveals a novel facet of nitrogen regulation in bacteria. Mol Microbiol 2007; 66:1523-35. [PMID: 18028310 DOI: 10.1111/j.1365-2958.2007.06016.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Ammonium movement across biological membranes is facilitated by a class of ubiquitous channel proteins from the Amt/Rh family. Amt proteins have also been implicated in cellular responses to ammonium availability in many organisms. Ammonium sensing by Amt in bacteria is mediated by complex formation with cytosolic proteins of the P(II) family. In this study we have characterized in vitro complex formation between the AmtB and P(II) proteins (GlnB and GlnZ) from the diazotrophic plant-associative bacterium Azospirillum brasilense. AmtB-P(II) complex formation only occurred in the presence of adenine nucleotides and was sensitive to 2-oxoglutarate when Mg(2+) and ATP were present, but not when ATP was substituted by ADP. We have also shown in vitro complex formation between GlnZ and the nitrogenase regulatory enzyme DraG, which was stimulated by ADP. The stoichiometry of this complex was 1:1 (DraG monomer : GlnZ trimer). We have previously reported that in vivo high levels of extracellular ammonium cause DraG to be sequestered to the cell membrane in an AmtB and GlnZ-dependent manner. We now report the reconstitution of a ternary complex involving AmtB, GlnZ and DraG in vitro. Sequestration of a regulatory protein by the membrane-bound AmtB-P(II) complex defines a new regulatory role for Amt proteins in Prokaryotes.
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Affiliation(s)
- Luciano F Huergo
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba-PR, Brazil
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