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Li K, Fang S, Zhang X, Wei X, Wu P, Zheng R, Liu L, Zhang H. Effects of Environmental Stresses on Synthesis of 2-Phenylethanol and IAA by Enterobacter sp. CGMCC 5087. Microorganisms 2024; 12:663. [PMID: 38674607 PMCID: PMC11052032 DOI: 10.3390/microorganisms12040663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/14/2024] [Accepted: 03/21/2024] [Indexed: 04/28/2024] Open
Abstract
2-Phenylethanol (2-PE) and indole-3-acetic acid (IAA) are important secondary metabolites produced by microorganisms, and their production are closely linked to the growth state of microorganisms and environmental factors. Enterobacter CGMCC 5087 can produce both 2-PE and IAA depending on α-ketoacid decarboxylase KDC4427. This study aimed to investigate the effects of different environment factors including osmotic pressure, temperature, and pH on the synthesis of 2-PE and IAA in Enterobacter sp. CGMCC 5087. The bacteria exhibited an enhanced capacity for 2-PE synthesis while not affecting IAA synthesis under 5% NaCl and pH 4.5 stress conditions. In an environment with pH 9.5, the synthesis capacity of 2-PE remained unchanged while the synthesis capacity of IAA decreased. The synthesis ability of 2-PE was enhanced with an increase in temperature within the range of 25 °C to 37 °C, while the synthesis capacity of IAA was not affected significantly. Additionally, the expression of KDC4427 varied under stress conditions. Under 5% NaCl stress and decreased temperature, expression of the KDC4427 gene was increased. However, altering pH did not result in significant differences in gene expression levels, while elevated temperature caused a decrease in gene expression. Furthermore, molecular docking and molecular dynamics simulations suggested that these conditions may induce fluctuation in the geometry shape of binding cavity, binding energy, and especially the dαC-C- value, which played key roles in affecting the enzyme activity. These results provide insights and strategies for the synthesis of metabolic products 2-PE and IAA in bacterial fermentation, even under unfavorable conditions.
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Affiliation(s)
- Ke Li
- College of Life Science and Technology, Inner Mongolia Normal University, Hohhot 010022, China; (K.L.); (X.W.); (P.W.)
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (S.F.); (X.Z.); (H.Z.)
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Senbiao Fang
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (S.F.); (X.Z.); (H.Z.)
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Xiao Zhang
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (S.F.); (X.Z.); (H.Z.)
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Xiaodi Wei
- College of Life Science and Technology, Inner Mongolia Normal University, Hohhot 010022, China; (K.L.); (X.W.); (P.W.)
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (S.F.); (X.Z.); (H.Z.)
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Pingle Wu
- College of Life Science and Technology, Inner Mongolia Normal University, Hohhot 010022, China; (K.L.); (X.W.); (P.W.)
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (S.F.); (X.Z.); (H.Z.)
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Rong Zheng
- College of Life Science and Technology, Inner Mongolia Normal University, Hohhot 010022, China; (K.L.); (X.W.); (P.W.)
| | - Lijuan Liu
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (S.F.); (X.Z.); (H.Z.)
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Haibo Zhang
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (S.F.); (X.Z.); (H.Z.)
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
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Elston R, Mulligan C, Thomas GH. Flipping the switch: dynamic modulation of membrane transporter activity in bacteria. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 37948297 DOI: 10.1099/mic.0.001412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
The controlled entry and expulsion of small molecules across the bacterial cytoplasmic membrane is essential for efficient cell growth and cellular homeostasis. While much is known about the transcriptional regulation of genes encoding transporters, less is understood about how transporter activity is modulated once the protein is functional in the membrane, a potentially more rapid and dynamic level of control. In this review, we bring together literature from the bacterial transport community exemplifying the extensive and diverse mechanisms that have evolved to rapidly modulate transporter function, predominantly by switching activity off. This includes small molecule feedback, inhibition by interaction with small peptides, regulation through binding larger signal transduction proteins and, finally, the emerging area of controlled proteolysis. Many of these examples have been discovered in the context of metal transport, which has to finely balance active accumulation of elements that are essential for growth but can also quickly become toxic if intracellular homeostasis is not tightly controlled. Consistent with this, these transporters appear to be regulated at multiple levels. Finally, we find common regulatory themes, most often through the fusion of additional regulatory domains to transporters, which suggest the potential for even more widespread regulation of transporter activity in biology.
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Affiliation(s)
- Rory Elston
- Department of Biology, University of York, York, UK
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3
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Ozturk TN, Coumoundouros C, Culham DE, Wood JM. Structural Determinants and Functional Significance of Dimerization for Osmosensing Transporter ProP in Escherichia coli. Biochemistry 2023; 62:118-133. [PMID: 36516499 DOI: 10.1021/acs.biochem.2c00393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Osmosensing transporter ProP forestalls cellular dehydration by detecting environments with high osmotic pressure and mediating the accumulation of organic osmolytes by bacterial cells. It is composed of 12 transmembrane helices with cytoplasmic N- and C-termini. In Escherichia coli, dimers form when the C-terminal domains of ProP molecules form homodimeric, antiparallel, α-helical coiled coils. No dominant negative effect was detected when inactive and active ProP molecules formed heterodimers in vivo. Purification of ProP in detergent dodecylmaltoside yielded monomers, which were functional after reconstitution in proteoliposomes. With other evidence, this suggests that ProP monomers function independently whether in the monomeric or dimeric state. Amino acid replacements that disrupted or reversed the coiled coil did not prevent in vivo dimerization of ProP detected with a bacterial two-hybrid system. Maleimide labeling detected no osmolality-dependent variation in the reactivities of cysteine residues introduced to transmembrane helix (TM) XII. In contrast, coarse-grained molecular dynamic simulations detected deformation of the lipid around TMs III and VI, on the lipid-exposed protein surface opposite to TM XII. This suggests that the dimer interface of ProP includes the surfaces of TMs III and VI, not of TM XII as previously suggested by crosslinking data. Homology modeling suggested that coiled-coil formation and dimerization via such an interface are not mutually exclusive. In previous work, alterations to the C-terminal coiled coil blocked co-localization of ProP with phospholipid cardiolipin at E. coli cell poles. Thus, dimerization may contribute to ProP targeting, adjust its lipid environment, and hence indirectly modify its osmotic stress response.
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Affiliation(s)
- Tugba N Ozturk
- Department of Biochemistry and Molecular Biophysics, Washington University in Saint Louis, Saint Louis, Missouri63110, United States.,Theoretical Molecular Biophysics Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland20814, United States
| | - Chelsea Coumoundouros
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, CanadaN1G 2 W1
| | - Doreen E Culham
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, CanadaN1G 2 W1
| | - Janet M Wood
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, CanadaN1G 2 W1
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4
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Schilz J, Clement C, Greiner F, Skerra A. Direct Affinity Purification of Long‐Acting PASylated Proteins with Therapeutic Potential Using L‐Prolinamide for Mild Elution. Angew Chem Int Ed Engl 2022; 61:e202200079. [PMID: 35325504 PMCID: PMC9320812 DOI: 10.1002/anie.202200079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Indexed: 11/09/2022]
Affiliation(s)
- Jonas Schilz
- Lehrstuhl für Biologische Chemie Technische Universität München Emil-Erlenmeyer-Forum 5 85354 Freising (Weihenstephan) Germany
| | - Charlotte Clement
- Lehrstuhl für Biologische Chemie Technische Universität München Emil-Erlenmeyer-Forum 5 85354 Freising (Weihenstephan) Germany
| | - Franziska Greiner
- Lehrstuhl für Biologische Chemie Technische Universität München Emil-Erlenmeyer-Forum 5 85354 Freising (Weihenstephan) Germany
| | - Arne Skerra
- Lehrstuhl für Biologische Chemie Technische Universität München Emil-Erlenmeyer-Forum 5 85354 Freising (Weihenstephan) Germany
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Schilz J, Clement C, Greiner F, Skerra A. Direct Affinity Purification of Long‐Acting PASylated Proteins with Therapeutic Potential Using L‐Prolinamide for Mild Elution. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202200079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jonas Schilz
- TUM: Technische Universitat Munchen Biological Chemistry GERMANY
| | | | | | - Arne Skerra
- Technische Universität München Lehrstuhl für Biologische Chemie Emil-Erlenmeyer-Forum 5 85354 Freising GERMANY
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Ozturk TN, Culham DE, Tempelhagen L, Wood JM, Lamoureux G. Salt-Dependent Interactions between the C-Terminal Domain of Osmoregulatory Transporter ProP of Escherichia coli and the Lipid Membrane. J Phys Chem B 2020; 124:8209-8220. [PMID: 32838524 DOI: 10.1021/acs.jpcb.0c03935] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Osmosensing transporter ProP detects the increase in cytoplasmic cation concentration associated with osmotically induced cell dehydration and mediates osmolyte uptake into bacteria. ProP is a 12-transmembrane helix protein with an α-helical, cytoplasmic C-terminal domain (CTD) linked to transmembrane helix XII (TM XII). It has been proposed that the CTD helix associates with the anionic membrane surface to lock ProP in an inactive conformation and that the release of the CTD may activate ProP. To investigate this possible activation mechanism, we have built and simulated a structural model in which the CTD was anchored to the membrane by TM XII and the CTD helix was associated with the membrane surface. Molecular dynamics simulations showed specific intrapeptide salt bridges forming when the CTD associated with the membrane. Experiments supported the presence of the salt bridge Lys447-Asp455 and suggested a role for these residues in osmosensing. Simulations performed at different salt concentrations showed weakened CTD-lipid interactions at 0.25 M KCl and gradual stiffening of the membrane with increasing salinity. These results suggest that salt cations may affect CTD release and activate ProP by increasing the order of membrane phospholipids.
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Affiliation(s)
- Tugba N Ozturk
- Department of Physics, Concordia University, Montreal QC H4B 1R6, Canada.,Centre for Research in Molecular Modeling, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Doreen E Culham
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Laura Tempelhagen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Janet M Wood
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Guillaume Lamoureux
- Centre for Research in Molecular Modeling, Concordia University, Montreal, Quebec H4B 1R6, Canada.,Department of Chemistry and Center for Computational and Integrative Biology, Rutgers University, Camden, New Jersey 08102, United States
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Tempelhagen L, Ayer A, Culham DE, Stocker R, Wood JM. Cultivation at high osmotic pressure confers ubiquinone 8–independent protection of respiration on Escherichia coli. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49909-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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8
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Tempelhagen L, Ayer A, Culham DE, Stocker R, Wood JM. Cultivation at high osmotic pressure confers ubiquinone 8-independent protection of respiration on Escherichia coli. J Biol Chem 2019; 295:981-993. [PMID: 31826918 DOI: 10.1074/jbc.ra119.011549] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/11/2019] [Indexed: 11/06/2022] Open
Abstract
Ubiquinone 8 (coenzyme Q8 or Q8) mediates electron transfer within the aerobic respiratory chain, mitigates oxidative stress, and contributes to gene expression in Escherichia coli In addition, Q8 was proposed to confer bacterial osmotolerance by accumulating during growth at high osmotic pressure and altering membrane stability. The osmolyte trehalose and membrane lipid cardiolipin accumulate in E. coli cells cultivated at high osmotic pressure. Here, Q8 deficiency impaired E. coli growth at low osmotic pressure and rendered growth osmotically sensitive. The Q8 deficiency impeded cellular O2 uptake and also inhibited the activities of two proton symporters, the osmosensing transporter ProP and the lactose transporter LacY. Q8 supplementation decreased membrane fluidity in liposomes, but did not affect ProP activity in proteoliposomes, which is respiration-independent. Liposomes and proteoliposomes prepared with E. coli lipids were used for these experiments. Similar oxygen uptake rates were observed for bacteria cultivated at low and high osmotic pressures. In contrast, respiration was dramatically inhibited when bacteria grown at the same low osmotic pressure were shifted to high osmotic pressure. Thus, respiration was restored during prolonged growth of E. coli at high osmotic pressure. Of note, bacteria cultivated at low and high osmotic pressures had similar Q8 concentrations. The protection of respiration was neither diminished by cardiolipin deficiency nor conferred by trehalose overproduction during growth at low osmotic pressure, but rather might be achieved by Q8-independent respiratory chain remodeling. We conclude that osmotolerance is conferred through Q8-independent protection of respiration, not by altering physical properties of the membrane.
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Affiliation(s)
- Laura Tempelhagen
- Department of Molecular and Cellular Biology, University of Guelph, 488 Gordon Street, Guelph, Ontario N1G 2W1, Canada
| | - Anita Ayer
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia.,St. Vincent's Clinical School, University of New South Wales Medicine, Kensington, New South Wales 2050, Australia
| | - Doreen E Culham
- Department of Molecular and Cellular Biology, University of Guelph, 488 Gordon Street, Guelph, Ontario N1G 2W1, Canada
| | - Roland Stocker
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia.,St. Vincent's Clinical School, University of New South Wales Medicine, Kensington, New South Wales 2050, Australia
| | - Janet M Wood
- Department of Molecular and Cellular Biology, University of Guelph, 488 Gordon Street, Guelph, Ontario N1G 2W1, Canada
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Czech L, Wilcken S, Czech O, Linne U, Brauner J, Smits SHJ, Galinski EA, Bremer E. Exploiting Substrate Promiscuity of Ectoine Hydroxylase for Regio- and Stereoselective Modification of Homoectoine. Front Microbiol 2019; 10:2745. [PMID: 31827466 PMCID: PMC6890836 DOI: 10.3389/fmicb.2019.02745] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 11/12/2019] [Indexed: 11/13/2022] Open
Abstract
Extant enzymes are not only highly efficient biocatalysts for a single, or a group of chemically closely related substrates but often have retained, as a mark of their evolutionary history, a certain degree of substrate ambiguity. We have exploited the substrate ambiguity of the ectoine hydroxylase (EctD), a member of the non-heme Fe(II)-containing and 2-oxoglutarate-dependent dioxygenase superfamily, for such a task. Naturally, the EctD enzyme performs a precise regio- and stereoselective hydroxylation of the ubiquitous stress protectant and chemical chaperone ectoine (possessing a six-membered pyrimidine ring structure) to yield trans-5-hydroxyectoine. Using a synthetic ectoine derivative, homoectoine, which possesses an expanded seven-membered diazepine ring structure, we were able to selectively generate, both in vitro and in vivo, trans-5-hydroxyhomoectoine. For this transformation, we specifically used the EctD enzyme from Pseudomonas stutzeri in a whole cell biocatalyst approach, as this enzyme exhibits high catalytic efficiency not only for its natural substrate ectoine but also for homoectoine. Molecular docking approaches with the crystal structure of the Sphingopyxis alaskensis EctD protein predicted the formation of trans-5-hydroxyhomoectoine, a stereochemical configuration that we experimentally verified by nuclear-magnetic resonance spectroscopy. An Escherichia coli cell factory expressing the P. stutzeri ectD gene from a synthetic promoter imported homoectoine via the ProU and ProP compatible solute transporters, hydroxylated it, and secreted the formed trans-5-hydroxyhomoectoine, independent from all currently known mechanosensitive channels, into the growth medium from which it could be purified by high-pressure liquid chromatography.
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Affiliation(s)
- Laura Czech
- Laboratory for Microbiology, Department of Biology, Philipps-Universität Marburg, Marburg, Germany
| | - Sarah Wilcken
- Laboratory for Microbiology, Department of Biology, Philipps-Universität Marburg, Marburg, Germany
| | - Oliver Czech
- Department of Chemistry, Philipps-Universität Marburg, Marburg, Germany
| | - Uwe Linne
- Department of Chemistry, Philipps-Universität Marburg, Marburg, Germany
| | - Jarryd Brauner
- Institute of Microbiology and Biotechnology, Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - Sander H J Smits
- Institute of Biochemistry, Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany.,Center for Structural Studies, Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany
| | - Erwin A Galinski
- Institute of Microbiology and Biotechnology, Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - Erhard Bremer
- Laboratory for Microbiology, Department of Biology, Philipps-Universität Marburg, Marburg, Germany.,SYNMIKRO Research Center, Philipps-Universität Marburg, Marburg, Germany
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Willson BJ, Chapman LNM, Thomas GH. Evolutionary dynamics of membrane transporters and channels: enhancing function through fusion. Curr Opin Genet Dev 2019; 58-59:76-86. [DOI: 10.1016/j.gde.2019.07.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 02/05/2023]
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Abstract
The cytoplasm of bacterial cells is a highly crowded cellular compartment that possesses considerable osmotic potential. As a result, and owing to the semipermeable nature of the cytoplasmic membrane and the semielastic properties of the cell wall, osmotically driven water influx will generate turgor, a hydrostatic pressure considered critical for growth and viability. Both increases and decreases in the external osmolarity inevitably trigger water fluxes across the cytoplasmic membrane, thus impinging on the degree of cellular hydration, molecular crowding, magnitude of turgor, and cellular integrity. Here, we assess mechanisms that permit the perception of osmotic stress by bacterial cells and provide an overview of the systems that allow them to genetically and physiologically cope with this ubiquitous environmental cue. We highlight recent developments implicating the secondary messenger c-di-AMP in cellular adjustment to osmotic stress and the role of osmotic forces in the life of bacteria-assembled in biofilms.
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Affiliation(s)
- Erhard Bremer
- Laboratory for Microbiology, Department of Biology; and Center for Synthetic Microbiology, Philipps-Universität Marburg, 35043 Marburg, Germany;
| | - Reinhard Krämer
- Institute of Biochemistry, University of Cologne, 50674 Cologne, Germany;
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