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Dergham Y, Le Coq D, Nicolas P, Bidnenko E, Dérozier S, Deforet M, Huillet E, Sanchez-Vizuete P, Deschamps J, Hamze K, Briandet R. Direct comparison of spatial transcriptional heterogeneity across diverse Bacillus subtilis biofilm communities. Nat Commun 2023; 14:7546. [PMID: 37985771 PMCID: PMC10661151 DOI: 10.1038/s41467-023-43386-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 11/08/2023] [Indexed: 11/22/2023] Open
Abstract
Bacillus subtilis can form various types of spatially organised communities on surfaces, such as colonies, pellicles and submerged biofilms. These communities share similarities and differences, and phenotypic heterogeneity has been reported for each type of community. Here, we studied spatial transcriptional heterogeneity across the three types of surface-associated communities. Using RNA-seq analysis of different regions or populations for each community type, we identified genes that are specifically expressed within each selected population. We constructed fluorescent transcriptional fusions for 17 of these genes, and observed their expression in submerged biofilms using time-lapse confocal laser scanning microscopy (CLSM). We found mosaic expression patterns for some genes; in particular, we observed spatially segregated cells displaying opposite regulation of carbon metabolism genes (gapA and gapB), indicative of distinct glycolytic or gluconeogenic regimes coexisting in the same biofilm region. Overall, our study provides a direct comparison of spatial transcriptional heterogeneity, at different scales, for the three main models of B. subtilis surface-associated communities.
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Affiliation(s)
- Yasmine Dergham
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
- Lebanese University, Faculty of Science, Beirut, Lebanon
| | - Dominique Le Coq
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
- Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS), INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Pierre Nicolas
- Université Paris-Saclay, INRAE, MAIAGE, Jouy-en-Josas, France
| | - Elena Bidnenko
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Sandra Dérozier
- Université Paris-Saclay, INRAE, MAIAGE, Jouy-en-Josas, France
| | - Maxime Deforet
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Jean Perrin, Paris, France
| | - Eugénie Huillet
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Pilar Sanchez-Vizuete
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Julien Deschamps
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Kassem Hamze
- Lebanese University, Faculty of Science, Beirut, Lebanon.
| | - Romain Briandet
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France.
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2
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Wei X, Chen Z, Liu A, Yang L, Xu Y, Cao M, He N. Advanced strategies for metabolic engineering of Bacillus to produce extracellular polymeric substances. Biotechnol Adv 2023; 67:108199. [PMID: 37330153 DOI: 10.1016/j.biotechadv.2023.108199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 05/24/2023] [Accepted: 06/11/2023] [Indexed: 06/19/2023]
Abstract
Extracellular polymeric substances are mainly synthesized via a variety of biosynthetic pathways in bacteria. Bacilli-sourced extracellular polymeric substances, such as exopolysaccharides (EPS) and poly-γ-glutamic acid (γ-PGA), can serve as active ingredients and hydrogels, and have other important industrial applications. However, the functional diversity and widespread applications of these extracellular polymeric substances, are hampered by their low yields and high costs. Biosynthesis of extracellular polymeric substances is very complex in Bacillus, and there is no detailed elucidation of the reactions and regulations among various metabolic pathways. Therefore, a better understanding of the metabolic mechanisms is required to broaden the functions and increase the yield of extracellular polymeric substances. This review systematically summarizes the biosynthesis and metabolic mechanisms of extracellular polymeric substances in Bacillus, providing an in-depth understanding of the relationships between EPS and γ-PGA synthesis. This review provides a better clarification of Bacillus metabolic mechanisms during extracellular polymeric substance secretion and thus benefits their application and commercialization.
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Affiliation(s)
- Xiaoyu Wei
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China; The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Zhen Chen
- College of Life Science, Xinyang Normal University, Xinyang 464000, China.
| | - Ailing Liu
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China; The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Lijie Yang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China; The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Yiyuan Xu
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China; The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China
| | - Mingfeng Cao
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China; The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China; Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen 361005, China.
| | - Ning He
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China; The Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005, China.
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3
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Castillo Alfonso F, Vigueras-Ramírez G, Rosales-Colunga LM, Del Monte-Martínez A, Olivares Hernández R. Propionate as the preferred carbon source to produce 3-indoleacetic acid in B. subtilis: comparative flux analysis using five carbon sources. Mol Omics 2021; 17:554-564. [PMID: 33972977 DOI: 10.1039/d1mo00039j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
3-Indoleacetic acid (IAA) is a phytohormone that promotes plant root growth, improving the use of nutrients and crop yield and it is been reported that bacteria of the genus Bacillus are capable of producing this phytohormone under various growth conditions. Considering this metabolic capability, in this work, Bacillus subtilis was cultivated in five different carbon sources: glucose, acetate, propionate, citrate and glycerol; and l-tryptophan (Trp) was used as an inducer for the IAA production. Based on the experimental results it was observed that the highest growth rate was achieved using glucose as a carbon source (μ = 0.12 h-1) and the lowest value was for citrate (μ = 0.08 h-1). On the other hand, the highest IAA production was obtained using propionate Yp/s = 0.975 (gIAA gTrp-1) and the lowest was when glucose was the substrate Yp/s = 0.803 (gIAA gTrp-1). In order to explore the metabolism and understand these differences, the experimental data was used to calculate the flux distribution using the genomic-scale metabolic model of Bacillus subtilis. Performing a comparative analysis it is observed that the fluxes towards precursors increase when propionate is the carbon source.
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Affiliation(s)
- Freddy Castillo Alfonso
- Posgrado en Ciencias Naturales e Ingeniería, Universidad Autónoma Metropolitana, Unidad Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe Cuajimalpa, Delegación Cuajimalpa, Ciudad de Mexico, 05348, Mexico
| | - Gabriel Vigueras-Ramírez
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana, Unidad Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe Cuajimalpa, Delegación Cuajimalpa, Ciudad de Mexico, 05348, Mexico.
| | - Luis Manuel Rosales-Colunga
- Facultad de Ingeniería, Universidad Autónoma de San Luis Potosí, Av. Dr Manuel Nava 8, Zona Universitaria, 78290, San Luis Potosí, S.L.P, Mexico
| | - Alberto Del Monte-Martínez
- Centro de Estudios de Proteínas, Univerisdad de La Habana, Calle 25 #455, e/J e I, vedado, 10400, Havana, Cuba
| | - Roberto Olivares Hernández
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana, Unidad Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe Cuajimalpa, Delegación Cuajimalpa, Ciudad de Mexico, 05348, Mexico.
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4
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Sharma K, Sultana T, Dahms TES, Dillon JAR. CcpN: a moonlighting protein regulating catabolite repression of gluconeogenic genes in Bacillus subtilis also affects cell length and interacts with DivIVA. Can J Microbiol 2020; 66:723-732. [PMID: 32762636 DOI: 10.1139/cjm-2020-0022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
CcpN is a transcriptional repressor in Bacillus subtilis that binds to the promoter region of gapB and pckA, downregulating their expression in the presence of glucose. CcpN also represses sr1, which encodes a small noncoding regulatory RNA that suppresses the arginine biosynthesis gene cluster. CcpN has homologues in other Gram-positive bacteria, including Enterococcus faecalis. We report the interaction of CcpN with DivIVA of B. subtilis as determined using bacterial two-hybrid and glutathione S-transferase pull-down assays. Insertional inactivation of CcpN leads to cell elongation and formation of straight chains of cells. These findings suggest that CcpN is a moonlighting protein involved in both gluconeogenesis and cell elongation.
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Affiliation(s)
- Kusum Sharma
- Department of Biochemistry, Microbiology and Immunology, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada.,Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK S7N 5E3, Canada
| | - Taranum Sultana
- Department of Chemistry and Biochemistry, 3737 Wascana Parkway, University of Regina, Regina, SK S4S 0A2, Canada
| | - Tanya E S Dahms
- Department of Chemistry and Biochemistry, 3737 Wascana Parkway, University of Regina, Regina, SK S4S 0A2, Canada
| | - Jo-Anne R Dillon
- Department of Biochemistry, Microbiology and Immunology, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada.,Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK S7N 5E3, Canada
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5
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Yang Z, Sun Q, Tan G, Zhang Q, Wang Z, Li C, Qi F, Wang W, Zhang L, Li Z. Engineering thermophilic Geobacillus thermoglucosidasius for riboflavin production. Microb Biotechnol 2020; 14:363-373. [PMID: 32096925 PMCID: PMC7936320 DOI: 10.1111/1751-7915.13543] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 01/17/2020] [Accepted: 01/24/2020] [Indexed: 01/17/2023] Open
Abstract
The potential advantages for fermentation production of chemicals at high temperatures are attractive, such as promoting the rate of biochemical reactions, reducing the risk of contamination and the energy consumption for fermenter cooling. In this work, we de novo engineered the thermophile Geobacillus thermoglucosidasius to produce riboflavin, since this bacterium can ferment diverse carbohydrates at an optimal temperature of 60°C with a high growth rate. We first introduced a heterogeneous riboflavin biosynthetic gene cluster and enabled the strain to produce detectable riboflavin (28.7 mg l−1). Then, with the aid of an improved gene replacement method, we preformed metabolic engineering in this strain, including replacement of ribCGtg with a mutant allele to weaken the consumption of riboflavin, manipulation of purine pathway to enhance precursor supply, deletion of ccpNGtg to tune central carbon catabolism towards riboflavin production and elimination of the lactate dehydrogenase gene to block the dominating product lactic acid. Finally, the engineered strain could produce riboflavin with the titre of 1034.5 mg l−1 after 12‐h fermentation in a mineral salt medium, indicating G. thermoglucosidasius is a promising host to develop high‐temperature cell factory of riboflavin production. This is the first demonstration of riboflavin production in thermophilic bacteria at an elevated temperature.
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Affiliation(s)
- Zhiheng Yang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Xuhui District, Shanghai, 200237, China
| | - Qingqing Sun
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Chaoyang District, Beijing, 100101, China
| | - Gaoyi Tan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Xuhui District, Shanghai, 200237, China
| | - Quanwei Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Chaoyang District, Beijing, 100101, China
| | - Zhengduo Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Xuhui District, Shanghai, 200237, China
| | - Chuan Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Xuhui District, Shanghai, 200237, China
| | - Fengxian Qi
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Chaoyang District, Beijing, 100101, China
| | - Weishan Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Xuhui District, Shanghai, 200237, China.,State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Chaoyang District, Beijing, 100101, China
| | - Lixin Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Xuhui District, Shanghai, 200237, China
| | - Zilong Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Chaoyang District, Beijing, 100101, China
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6
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Sharma K, Sultana T, Liao M, Dahms TES, Dillon JAR. EF1025, a Hypothetical Protein From Enterococcus faecalis, Interacts With DivIVA and Affects Cell Length and Cell Shape. Front Microbiol 2020; 11:83. [PMID: 32117116 PMCID: PMC7028823 DOI: 10.3389/fmicb.2020.00083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 01/15/2020] [Indexed: 01/22/2023] Open
Abstract
DivIVA plays multifaceted roles in Gram-positive organisms through its association with various cell division and non-cell division proteins. We report a novel DivIVA interacting protein in Enterococcus faecalis, named EF1025 (encoded by EF1025), which is conserved in Gram-positive bacteria. The interaction of EF1025 with DivIVAEf was confirmed by Bacterial Two-Hybrid, Glutathione S-Transferase pull-down, and co-immunoprecipitation assays. EF1025, which contains a DNA binding domain and two Cystathionine β-Synthase (CBS) domains, forms a decamer mediated by the two CBS domains. Viable cells were recovered after insertional inactivation or deletion of EF1025 only through complementation of EF1025 in trans. These cells were longer than the average length of E. faecalis cells and had distorted shapes. Overexpression of EF1025 also resulted in cell elongation. Immuno-staining revealed comparable localization patterns of EF1025 and DivIVAEf in the later stages of division in E. faecalis cells. In summary, EF1025 is a novel DivIVA interacting protein influencing cell length and morphology in E. faecalis.
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Affiliation(s)
- Kusum Sharma
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada.,Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Taranum Sultana
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | - Mingmin Liao
- Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Tanya E S Dahms
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | - Jo-Anne R Dillon
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada.,Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, Saskatoon, SK, Canada
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7
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McKinlay JB, Cook GM, Hards K. Microbial energy management-A product of three broad tradeoffs. Adv Microb Physiol 2020; 77:139-185. [PMID: 34756210 DOI: 10.1016/bs.ampbs.2020.09.001] [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] [Indexed: 12/11/2022]
Abstract
Wherever thermodynamics allows, microbial life has evolved to transform and harness energy. Microbial life thus abounds in the most unexpected places, enabled by profound metabolic diversity. Within this diversity, energy is transformed primarily through variations on a few core mechanisms. Energy is further managed by the physiological processes of cell growth and maintenance that use energy. Some aspects of microbial physiology are streamlined for energetic efficiency while other aspects seem suboptimal or even wasteful. We propose that the energy that a microbe harnesses and devotes to growth and maintenance is a product of three broad tradeoffs: (i) economic, trading enzyme synthesis or operational cost for functional benefit, (ii) environmental, trading optimization for a single environment for adaptability to multiple environments, and (iii) thermodynamic, trading energetic yield for forward metabolic flux. Consideration of these tradeoffs allows one to reconcile features of microbial physiology that seem to opposingly promote either energetic efficiency or waste.
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Affiliation(s)
- James B McKinlay
- Department of Biology, Indiana University, Bloomington, IN, United States.
| | - Gregory M Cook
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Kiel Hards
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
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8
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Nguyen HTM, Akanuma G, Hoa TTM, Nakai Y, Kimura K, Yamamoto K, Inaoka T. Ribosome Reconstruction during Recovery from High-Hydrostatic-Pressure-Induced Injury in Bacillus subtilis. Appl Environ Microbiol 2019; 86:e01640-19. [PMID: 31604775 PMCID: PMC6912085 DOI: 10.1128/aem.01640-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 10/03/2019] [Indexed: 02/07/2023] Open
Abstract
Vegetative cells of Bacillus subtilis can recover from injury after high-hydrostatic-pressure (HHP) treatment at 250 MPa. DNA microarray analysis revealed that substantial numbers of ribosomal genes and translation-related genes (e.g., translation initiation factors) were upregulated during the growth arrest phase after HHP treatment. The transcript levels of cold shock-responsive genes, whose products play key roles in efficient translation, and heat shock-responsive genes, whose products mediate correct protein folding or degrade misfolded proteins, were also upregulated. In contrast, the transcript level of hpf, whose product (Hpf) is involved in ribosome inactivation through the dimerization of 70S ribosomes, was downregulated during the growth arrest phase. Sucrose density gradient sedimentation analysis revealed that ribosomes were dissociated in a pressure-dependent manner and then reconstructed. We also found that cell growth after HHP-induced injury was apparently inhibited by the addition of Mn2+ or Zn2+ to the recovery medium. Ribosome reconstruction in the HHP-injured cells was also significantly delayed in the presence of Mn2+ or Zn2+ Moreover, Zn2+, but not Mn2+, promoted dimer formation of 70S ribosomes in the HHP-injured cells. Disruption of the hpf gene suppressed the Zn2+-dependent accumulation of ribosome dimers, partially relieving the inhibitory effect of Zn2+ on the growth recovery of HHP-treated cells. In contrast, it was likely that Mn2+ prevented ribosome reconstruction without stimulating ribosome dimerization. Our results suggested that both Mn2+ and Zn2+ can prevent ribosome reconstruction, thereby delaying the growth recovery of HHP-injured B. subtilis cells.IMPORTANCE HHP treatment is used as a nonthermal processing technology in the food industry to inactivate bacteria while retaining high quality of foods under suppressed chemical reactions. However, some populations of bacterial cells may survive the inactivation. Although the survivors are in a transient nongrowing state due to HHP-induced injury, they can recover from the injury and then start growing, depending on the postprocessing conditions. The recovery process in terms of cellular components after the injury remains unclear. Transcriptome analysis using vegetative cells of Bacillus subtilis revealed that the translational machinery can preferentially be reconstructed after HHP treatment. We found that both Mn2+ and Zn2+ prolonged the growth-arrested stage of HHP-injured cells by delaying ribosome reconstruction. It is likely that ribosome reconstruction is crucial for the recovery of growth ability in HHP-injured cells. This study provides further understanding of the recovery process in HHP-injured B. subtilis cells.
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Affiliation(s)
- Huyen Thi Minh Nguyen
- Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
- Institute of Biotechnology, Vietnam Academy of Science and Technology, Ha Noi, Viet Nam
| | | | - Tu Thi Minh Hoa
- Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
- Institute of Biotechnology, Vietnam Academy of Science and Technology, Ha Noi, Viet Nam
| | - Yuji Nakai
- Institute of Regional Innovation, Hirosaki University, Aomori, Japan
| | - Keitarou Kimura
- Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Kazutaka Yamamoto
- Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Takashi Inaoka
- Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
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9
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Buffing MF, Link H, Christodoulou D, Sauer U. Capacity for instantaneous catabolism of preferred and non-preferred carbon sources in Escherichia coli and Bacillus subtilis. Sci Rep 2018; 8:11760. [PMID: 30082753 PMCID: PMC6079084 DOI: 10.1038/s41598-018-30266-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 07/26/2018] [Indexed: 02/08/2023] Open
Abstract
Making the right choice for nutrient consumption in an ever-changing environment is a key factor for evolutionary success of bacteria. Here we investigate the regulatory mechanisms that enable dynamic adaptation between non-preferred and preferred carbon sources for the model Gram-negative and -positive species Escherichia coli and Bacillus subtilis, respectively. We focus on the ability for instantaneous catabolism of a gluconeogenic carbon source upon growth on a glycolytic carbon source and vice versa. By following isotopic tracer dynamics on a 1–2 minute scale, we show that flux reversal from the preferred glucose to non-preferred pyruvate as the sole carbon source is primarily transcriptionally regulated. In the opposite direction, however, E. coli can reverse its flux instantaneously by means of allosteric regulation, whereas in B. subtilis this flux reversal is transcriptionally regulated. Upon removal of transcriptional regulation, B. subtilis assumes the ability of instantaneous glucose catabolism. Using an approach that combines quantitative metabolomics and kinetic modelling, we then identify the additionally necessary key metabolite-enzyme interactions that implement the instantaneous flux reversal in the transcriptionally deregulated B. subtilis, and validate the most relevant allosteric interactions.
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Affiliation(s)
- Marieke F Buffing
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.,Life Science Zurich PhD Program on Systems Biology, Zurich, Switzerland
| | - Hannes Link
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Dimitris Christodoulou
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.,Life Science Zurich PhD Program on Systems Biology, Zurich, Switzerland
| | - Uwe Sauer
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.
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10
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Integrated whole-genome and transcriptome sequence analysis reveals the genetic characteristics of a riboflavin-overproducing Bacillus subtilis. Metab Eng 2018; 48:138-149. [DOI: 10.1016/j.ymben.2018.05.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 05/17/2018] [Accepted: 05/31/2018] [Indexed: 11/23/2022]
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11
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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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12
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Raafat D, Leib N, Wilmes M, François P, Schrenzel J, Sahl HG. Development of in vitro resistance to chitosan is related to changes in cell envelope structure of Staphylococcus aureus. Carbohydr Polym 2016; 157:146-155. [PMID: 27987856 DOI: 10.1016/j.carbpol.2016.09.075] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/23/2016] [Accepted: 09/23/2016] [Indexed: 10/20/2022]
Abstract
The bacterial cell envelope is believed to be a principal target for initiating the staphylocidal pathway of chitosan. The present study was therefore designed to investigate possible changes in cell surface phenotypes related to the in vitro chitosan resistance development in the laboratory strain S. aureus SG511-Berlin. Following a serial passage experiment, a stable chitosan-resistant variant (CRV) was identified, exhibiting >50-fold reduction in its sensitivity towards chitosan. Our analyses of the CRV identified phenotypic and genotypic features that readily distinguished it from its chitosan-susceptible parental strain, including: (i) a lower overall negative cell surface charge; (ii) cross-resistance to a number of antimicrobial agents; (iii) major alterations in cell envelope structure, cellular bioenergetics and metabolism (based on transcriptional profiling); and (iv) a repaired sensor histidine kinase GraS. Our data therefore suggest a close nexus between changes in cell envelope properties with the in vitro chitosan-resistant phenotype in S. aureus SG511-Berlin.
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Affiliation(s)
- Dina Raafat
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology Unit, University of Bonn, D-53115 Bonn, Germany.
| | - Nicole Leib
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology Unit, University of Bonn, D-53115 Bonn, Germany.
| | - Miriam Wilmes
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology Unit, University of Bonn, D-53115 Bonn, Germany.
| | - Patrice François
- Genomic Research Laboratory, Division of Infectious Diseases, University of Geneva Hospitals, CH-1211 Geneva, Switzerland.
| | - Jacques Schrenzel
- Genomic Research Laboratory, Division of Infectious Diseases, University of Geneva Hospitals, CH-1211 Geneva, Switzerland.
| | - Hans-Georg Sahl
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology Unit, University of Bonn, D-53115 Bonn, Germany.
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13
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Enhancement of riboflavin production by deregulating gluconeogenesis in Bacillus subtilis. World J Microbiol Biotechnol 2014; 30:1893-900. [DOI: 10.1007/s11274-014-1611-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 01/19/2014] [Indexed: 10/25/2022]
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14
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Chubukov V, Uhr M, Le Chat L, Kleijn RJ, Jules M, Link H, Aymerich S, Stelling J, Sauer U. Transcriptional regulation is insufficient to explain substrate-induced flux changes in Bacillus subtilis. Mol Syst Biol 2013; 9:709. [PMID: 24281055 PMCID: PMC4039378 DOI: 10.1038/msb.2013.66] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 10/23/2013] [Indexed: 12/18/2022] Open
Abstract
Regulation of enzyme expression is one key mechanism by which cells control their metabolic programs. In this work, a quantitative analysis of metabolism in a model bacterium under different conditions shows that expression alone cannot explain the majority of the observed metabolic changes. ![]()
Most enzymes are indeed highly expressed in conditions where they are more active. Quantitatively, however, the observed changes in expression between conditions do not match the changes in activity for most enzymes. A good quantitative match is only observed for enzymes involved in the TCA cycle. Metabolomics reveals that increased substrate availability explains only a few instances of changes in activity.
One of the key ways in which microbes are thought to regulate their metabolism is by modulating the availability of enzymes through transcriptional regulation. However, the limited success of efforts to manipulate metabolic fluxes by rewiring the transcriptional network has cast doubt on the idea that transcript abundance controls metabolic fluxes. In this study, we investigate control of metabolic flux in the model bacterium Bacillus subtilis by quantifying fluxes, transcripts, and metabolites in eight metabolic states enforced by different environmental conditions. We find that most enzymes whose flux switches between on and off states, such as those involved in substrate uptake, exhibit large corresponding transcriptional changes. However, for the majority of enzymes in central metabolism, enzyme concentrations were insufficient to explain the observed fluxes—only for a number of reactions in the tricarboxylic acid cycle were enzyme changes approximately proportional to flux changes. Surprisingly, substrate changes revealed by metabolomics were also insufficient to explain observed fluxes, leaving a large role for allosteric regulation and enzyme modification in the control of metabolic fluxes.
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Affiliation(s)
- Victor Chubukov
- Institute of Molecular System Biology, ETH Zurich, Zurich, Switzerland
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15
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Kochanowski K, Sauer U, Chubukov V. Somewhat in control--the role of transcription in regulating microbial metabolic fluxes. Curr Opin Biotechnol 2013; 24:987-93. [PMID: 23571096 DOI: 10.1016/j.copbio.2013.03.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 03/13/2013] [Accepted: 03/14/2013] [Indexed: 10/27/2022]
Abstract
The most common way for microbes to control their metabolism is by controlling enzyme levels through transcriptional regulation. Yet recent studies have shown that in many cases, perturbations to the transcriptional regulatory network do not result in altered metabolic phenotypes on the level of the flux distribution. We suggest that this may be a consequence of cells protecting their metabolism against stochastic fluctuations in expression as well as enabling a fast response for those fluxes that may need to be changed quickly. Furthermore, it is impossible for a regulatory program to guarantee optimal expression levels in all conditions. Several studies have found examples of demonstrably suboptimal regulation of gene expression, and improvements to the regulatory network have been investigated in laboratory evolution experiments.
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Affiliation(s)
- Karl Kochanowski
- Institute of Molecular Systems Biology, ETH Zurich, Wolfgang-Pauli-Str. 16, CH-8093 Zurich, Switzerland; Life Science Zurich PhD Program on Systems Biology, Zurich, Switzerland
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16
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Meyer FM, Stülke J. Malate metabolism in Bacillus subtilis: distinct roles for three classes of malate-oxidizing enzymes. FEMS Microbiol Lett 2012; 339:17-22. [PMID: 23136871 DOI: 10.1111/1574-6968.12041] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 11/01/2012] [Accepted: 11/01/2012] [Indexed: 11/30/2022] Open
Abstract
The Gram-positive soil bacterium Bacillus subtilis uses glucose and malate as the preferred carbon sources. In the presence of either glucose or malate, the expression of genes and operons for the utilization of secondary carbon sources is subject to carbon catabolite repression. While glucose is a preferred substrate in many organisms from bacteria to man, the factors that contribute to the preference for malate have so far remained elusive. In this work, we have studied the contribution of the different malate-metabolizing enzymes in B. subtilis, and we have elucidated their distinct functions. The malate dehydrogenase and the phosphoenolpyruvate carboxykinase are both essential for malate utilization; they introduce malate into gluconeogenesis. The NADPH-generating malic enzyme YtsJ is important to establish the cellular pools of NADPH for anabolic reactions. Finally, the NADH-generating malic enzymes MaeA, MalS, and MleA are involved in keeping the ATP levels high. Together, this unique array of distinct activities makes malate a preferred carbon source for B. subtilis.
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Affiliation(s)
- Frederik M Meyer
- Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August University Göttingen, Göttingen, Germany
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17
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de Jong IG, Veening JW, Kuipers OP. Single cell analysis of gene expression patterns during carbon starvation in Bacillus subtilis reveals large phenotypic variation. Environ Microbiol 2012; 14:3110-21. [PMID: 23033921 DOI: 10.1111/j.1462-2920.2012.02892.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/30/2012] [Accepted: 09/02/2012] [Indexed: 11/30/2022]
Abstract
How cells dynamically respond to fluctuating environmental conditions depends on the architecture and noise of the underlying genetic circuits. Most work characterizing stress pathways in the model bacterium Bacillus subtilis has been performed on bulk cultures using ensemble assays. However, investigating the single cell response to stress is important since noise might generate significant phenotypic heterogeneity. Here, we study the stress response to carbon source starvation and compare both population and single cell data. Using a top-down approach, we investigate the transcriptional dynamics of various stress-related genes of B. subtilis in response to carbon source starvation and to increased cell density. Our data reveal that most of the tested gene-regulatory networks respond highly heterogeneously to starvation and cells show a large degree of variation in gene expression. The level of highly dynamic diversification within B. subtilis populations under changing environments reflects the necessity to study cells at the single cell level.
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Affiliation(s)
- Imke G de Jong
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Synthetic Biology, University of Groningen, Nijenborgh 7, 9747, AG, Groningen, The Netherlands
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18
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Kim J, Reed JL. RELATCH: relative optimality in metabolic networks explains robust metabolic and regulatory responses to perturbations. Genome Biol 2012; 13:R78. [PMID: 23013597 PMCID: PMC3506949 DOI: 10.1186/gb-2012-13-9-r78] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 08/30/2012] [Accepted: 09/26/2012] [Indexed: 11/25/2022] Open
Abstract
Predicting cellular responses to perturbations is an important task in systems biology. We report a new approach, RELATCH, which uses flux and gene expression data from a reference state to predict metabolic responses in a genetically or environmentally perturbed state. Using the concept of relative optimality, which considers relative flux changes from a reference state, we hypothesize a relative metabolic flux pattern is maintained from one state to another, and that cells adapt to perturbations using metabolic and regulatory reprogramming to preserve this relative flux pattern. This constraint-based approach will have broad utility where predictions of metabolic responses are needed.
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Affiliation(s)
- Joonhoon Kim
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, USA
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19
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Rühl M, Le Coq D, Aymerich S, Sauer U. 13C-flux analysis reveals NADPH-balancing transhydrogenation cycles in stationary phase of nitrogen-starving Bacillus subtilis. J Biol Chem 2012; 287:27959-70. [PMID: 22740702 DOI: 10.1074/jbc.m112.366492] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
In their natural habitat, microorganisms are typically confronted with nutritional limitations that restrict growth and force them to persevere in a stationary phase. Despite the importance of this phase, little is known about the metabolic state(s) that sustains it. Here, we investigate metabolically active but non-growing Bacillus subtilis during nitrogen starvation. In the absence of biomass formation as the major NADPH sink, the intracellular flux distribution in these resting B. subtilis reveals a large apparent catabolic NADPH overproduction of 5.0 ± 0.6 mmol g(-1)h(-1) that was partly caused by high pentose phosphate pathway fluxes. Combining transcriptome analysis, stationary (13)C-flux analysis in metabolic deletion mutants, (2)H-labeling experiments, and kinetic flux profiling, we demonstrate that about half of the catabolic excess NADPH is oxidized by two transhydrogenation cycles, i.e. isoenzyme pairs of dehydrogenases with different cofactor specificities that operate in reverse directions. These transhydrogenation cycles were constituted by the combined activities of the glyceraldehyde 3-phosphate dehydrogenases GapA/GapB and the malic enzymes MalS/YtsJ. At least an additional 6% of the overproduced NADPH is reoxidized by continuous cycling between ana- and catabolism of glutamate. Furthermore, in vitro enzyme data show that a not yet identified transhydrogenase could potentially reoxidize ∼20% of the overproduced NADPH. Overall, we demonstrate the interplay between several metabolic mechanisms that concertedly enable network-wide NADPH homeostasis under conditions of high catabolic NADPH production in the absence of cell growth in B. subtilis.
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Affiliation(s)
- Martin Rühl
- Institute of Molecular Systems Biology, ETH Zurich, CH-8093 Zurich, Switzerland
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20
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Schuetz R, Zamboni N, Zampieri M, Heinemann M, Sauer U. Multidimensional optimality of microbial metabolism. Science 2012; 336:601-4. [PMID: 22556256 DOI: 10.1126/science.1216882] [Citation(s) in RCA: 273] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Although the network topology of metabolism is well known, understanding the principles that govern the distribution of fluxes through metabolism lags behind. Experimentally, these fluxes can be measured by (13)C-flux analysis, and there has been a long-standing interest in understanding this functional network operation from an evolutionary perspective. On the basis of (13)C-determined fluxes from nine bacteria and multi-objective optimization theory, we show that metabolism operates close to the Pareto-optimal surface of a three-dimensional space defined by competing objectives. Consistent with flux data from evolved Escherichia coli, we propose that flux states evolve under the trade-off between two principles: optimality under one given condition and minimal adjustment between conditions. These principles form the forces by which evolution shapes metabolic fluxes in microorganisms' environmental context.
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Affiliation(s)
- Robert Schuetz
- Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule Zurich, Zurich, Switzerland
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21
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Reconciling molecular regulatory mechanisms with noise patterns of bacterial metabolic promoters in induced and repressed states. Proc Natl Acad Sci U S A 2011; 109:155-60. [PMID: 22190493 DOI: 10.1073/pnas.1110541108] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Assessing gene expression noise in order to obtain mechanistic insights requires accurate quantification of gene expression on many individual cells over a large dynamic range. We used a unique method based on 2-photon fluorescence fluctuation microscopy to measure directly, at the single cell level and with single-molecule sensitivity, the absolute concentration of fluorescent proteins produced from the two Bacillus subtilis promoters that control the switch between glycolysis and gluconeogenesis. We quantified cell-to-cell variations in GFP concentrations in reporter strains grown on glucose or malate, including very weakly transcribed genes under strong catabolite repression. Results revealed strong transcriptional bursting, particularly for the glycolytic promoter. Noise pattern parameters of the two antagonistic promoters controlling the nutrient switch were differentially affected on glycolytic and gluconeogenic carbon sources, discriminating between the different mechanisms that control their activity. Our stochastic model for the transcription events reproduced the observed noise patterns and identified the critical parameters responsible for the differences in expression profiles of the promoters. The model also resolved apparent contradictions between in vitro operator affinity and in vivo repressor activity at these promoters. Finally, our results demonstrate that negative feedback is not noise-reducing in the case of strong transcriptional bursting.
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22
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Pohl S, Tu WY, Aldridge PD, Gillespie C, Hahne H, Mäder U, Read TD, Harwood CR. Combined proteomic and transcriptomic analysis of the response of Bacillus anthracis
to oxidative stress. Proteomics 2011; 11:3036-55. [DOI: 10.1002/pmic.201100085] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 03/28/2011] [Accepted: 04/05/2011] [Indexed: 11/12/2022]
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23
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Yu WB, Gao SH, Yin CY, Zhou Y, Ye BC. Comparative transcriptome analysis of Bacillus subtilis responding to dissolved oxygen in adenosine fermentation. PLoS One 2011; 6:e20092. [PMID: 21625606 PMCID: PMC3097244 DOI: 10.1371/journal.pone.0020092] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 04/12/2011] [Indexed: 12/20/2022] Open
Abstract
Dissolved oxygen (DO) is an important factor for adenosine fermentation. Our previous experiments have shown that low oxygen supply in the growth period was optimal for high adenosine yield. Herein, to better understand the link between oxygen supply and adenosine productivity in B. subtilis (ATCC21616), we sought to systematically explore the effect of DO on genetic regulation and metabolism through transcriptome analysis. The microarrays representing 4,106 genes were used to study temporal transcript profiles of B. subtilis fermentation in response to high oxygen supply (agitation 700 r/min) and low oxygen supply (agitation 450 r/min). The transcriptome data analysis revealed that low oxygen supply has three major effects on metabolism: enhance carbon metabolism (glucose metabolism, pyruvate metabolism and carbon overflow), inhibit degradation of nitrogen sources (glutamate family amino acids and xanthine) and purine synthesis. Inhibition of xanthine degradation was the reason that low oxygen supply enhanced adenosine production. These provide us with potential targets, which can be modified to achieve higher adenosine yield. Expression of genes involved in energy, cell type differentiation, protein synthesis was also influenced by oxygen supply. These results provided new insights into the relationship between oxygen supply and metabolism.
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Affiliation(s)
- Wen-Bang Yu
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Shu-Hong Gao
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Chun-Yun Yin
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Ying Zhou
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Bang-Ce Ye
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- * E-mail:
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24
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Likić VA, McConville MJ, Lithgow T, Bacic A. Systems biology: the next frontier for bioinformatics. Adv Bioinformatics 2011; 2010:268925. [PMID: 21331364 PMCID: PMC3038413 DOI: 10.1155/2010/268925] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 11/01/2010] [Indexed: 01/01/2023] Open
Abstract
Biochemical systems biology augments more traditional disciplines, such as genomics, biochemistry and molecular biology, by championing (i) mathematical and computational modeling; (ii) the application of traditional engineering practices in the analysis of biochemical systems; and in the past decade increasingly (iii) the use of near-comprehensive data sets derived from 'omics platform technologies, in particular "downstream" technologies relative to genome sequencing, including transcriptomics, proteomics and metabolomics. The future progress in understanding biological principles will increasingly depend on the development of temporal and spatial analytical techniques that will provide high-resolution data for systems analyses. To date, particularly successful were strategies involving (a) quantitative measurements of cellular components at the mRNA, protein and metabolite levels, as well as in vivo metabolic reaction rates, (b) development of mathematical models that integrate biochemical knowledge with the information generated by high-throughput experiments, and (c) applications to microbial organisms. The inevitable role bioinformatics plays in modern systems biology puts mathematical and computational sciences as an equal partner to analytical and experimental biology. Furthermore, mathematical and computational models are expected to become increasingly prevalent representations of our knowledge about specific biochemical systems.
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Affiliation(s)
- Vladimir A. Likić
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Malcolm J. McConville
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, 3010, Australia
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Trevor Lithgow
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, 3800, Australia
| | - Antony Bacic
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, 3010, Australia
- Australian Centre for Plant Functional Genomics, School of Botany, The University of Melbourne, Parkville, VIC, 3010, Australia
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25
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Bridging the gap between fluxomics and industrial biotechnology. J Biomed Biotechnol 2011; 2010:460717. [PMID: 21274256 PMCID: PMC3022177 DOI: 10.1155/2010/460717] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 11/08/2010] [Indexed: 12/30/2022] Open
Abstract
Metabolic flux analysis is a vital tool used to determine the ultimate output of cellular metabolism and thus detect biotechnologically relevant bottlenecks in productivity. 13C-based metabolic flux analysis (13C-MFA) and flux balance analysis (FBA) have many potential applications in biotechnology. However, noteworthy hurdles in fluxomics study are still present. First, several technical difficulties in both 13C-MFA and FBA severely limit the scope of fluxomics findings and the applicability of obtained metabolic information. Second, the complexity of metabolic regulation poses a great challenge for precise prediction and analysis of metabolic networks, as there are gaps between fluxomics results and other omics studies. Third, despite identified metabolic bottlenecks or sources of host stress from product synthesis, it remains difficult to overcome inherent metabolic robustness or to efficiently import and express nonnative pathways. Fourth, product yields often decrease as the number of enzymatic steps increases. Such decrease in yield may not be caused by rate-limiting enzymes, but rather is accumulated through each enzymatic reaction. Fifth, a high-throughput fluxomics tool hasnot been developed for characterizing nonmodel microorganisms and maximizing their application in industrial biotechnology. Refining fluxomics tools and understanding these obstacles will improve our ability to engineer highlyefficient metabolic pathways in microbial hosts.
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26
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Lee SY, Park JM, Kim TY. Application of Metabolic Flux Analysis in Metabolic Engineering. Methods Enzymol 2011; 498:67-93. [DOI: 10.1016/b978-0-12-385120-8.00004-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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27
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Heinemann M, Sauer U. Systems biology of microbial metabolism. Curr Opin Microbiol 2010; 13:337-43. [PMID: 20219420 DOI: 10.1016/j.mib.2010.02.005] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 02/13/2010] [Indexed: 12/20/2022]
Abstract
One current challenge in metabolic systems biology is to map out the regulation networks that control metabolism. From progress in this area, we conclude that non-transcriptional mechanisms (e.g. metabolite-protein interactions and protein phosphorylation) are highly relevant in actually controlling metabolic function. Furthermore, recent results highlight more functions of enzymes and metabolites than currently appreciated in genome-scale metabolic reconstructions, thereby adding another level of complexity. Combining experimental analyses and modeling efforts we are also beginning to understand how metabolic behavior emerges. Particularly, we recognize that metabolism is not simply a dull workhorse process but rather takes very active control of itself and other cellular processes, rendering true system-level understanding of metabolism possibly more difficult than for other cellular systems.
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Affiliation(s)
- Matthias Heinemann
- ETH Zurich, Institute of Molecular Systems Biology, Wolfgang-Pauli-Str. 16, 8093 Zurich, Switzerland.
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28
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Dauner M. From fluxes and isotope labeling patterns towards in silico cells. Curr Opin Biotechnol 2010; 21:55-62. [DOI: 10.1016/j.copbio.2010.01.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2009] [Revised: 01/23/2010] [Accepted: 01/31/2010] [Indexed: 10/19/2022]
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29
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Zamboni N, Sauer U. Novel biological insights through metabolomics and 13C-flux analysis. Curr Opin Microbiol 2009; 12:553-8. [PMID: 19744879 DOI: 10.1016/j.mib.2009.08.003] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 07/31/2009] [Accepted: 08/06/2009] [Indexed: 11/28/2022]
Abstract
Metabolomics and (13)C-flux analysis have become instrumental for analyzing cellular metabolism and its regulation. Driven primarily by technical advances in mass spectrometry-based analytics, they provide unmatched readouts on metabolic state and activity. Functional genomics leverages metabolomics for the discovery of novel enzymes and unexpected secondary activities of annotated enzymes. (13)C-flux analyses are frequently used for empirical elucidation of pathways in poorly characterized species and for network-wide analysis of mechanisms that realize energy and redox balancing. Integration of metabolomics, (13)C-flux analysis and other data enable the condition-dependent characterization of regulatory circuits that ultimately govern the metabolic phenotype.
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Affiliation(s)
- Nicola Zamboni
- Institute of Molecular Systems Biology, ETH Zurich, 8093 Zurich, Switzerland
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30
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Licht A, Brantl S. The transcriptional repressor CcpN from Bacillus subtilis uses different repression mechanisms at different promoters. J Biol Chem 2009; 284:30032-8. [PMID: 19726675 DOI: 10.1074/jbc.m109.033076] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CcpN, a transcriptional repressor from Bacillus subtilis that is responsible for the carbon catabolite repression of three genes, has been characterized in detail in the past 4 years. However, nothing is known about the actual repression mechanism as yet. Here, we present a detailed study on how CcpN exerts its repression effect at its three known target promoters of the genes sr1, pckA, and gapB. Using gel shift assays under non-repressive and repressive conditions, we showed that CcpN and RNA polymerase can bind simultaneously and that CcpN does not prevent RNA polymerase (RNAP) binding to the promoter. Furthermore, we investigated the effect of CcpN on open complex formation and demonstrate that CcpN also does not act at this step of transcription initiation at the sr1 and pckA and presumably at the gapB promoter. Investigation of abortive transcript synthesis revealed that CcpN acts differently at the three promoters: At the sr1 and pckA promoter, promoter clearance is impeded by CcpN, whereas synthesis of abortive transcripts is repressed at the gapB promoter. Eventually, we demonstrated with Far Western blots and co-elution experiments that CcpN is able to interact with the RNAP alpha-subunit, which completes the picture of the requirements for the repressive action of CcpN. On the basis of the presented results, we propose a new working model for CcpN action.
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Affiliation(s)
- Andreas Licht
- Arbeitsgruppe Bakteriengenetik, Friedrich-Schiller-Universität, 07743 Jena, Germany.
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The Bacillus subtilis ywjI (glpX) gene encodes a class II fructose-1,6-bisphosphatase, functionally equivalent to the class III Fbp enzyme. J Bacteriol 2009; 191:3168-71. [PMID: 19270101 DOI: 10.1128/jb.01783-08] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We present here experimental evidence that the Bacillus subtilis ywjI gene encodes a class II fructose-1,6-bisphosphatase, functionally equivalent to the fbp-encoded class III enzyme, and constitutes with the upstream gene, murAB, an operon transcribed at the same level under glycolytic or gluconeogenic conditions.
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