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Ribeiro ALJL, Pérez-Arnaiz P, Sánchez-Costa M, Pérez L, Almendros M, van Vliet L, Gielen F, Lim J, Charnock S, Hollfelder F, González-Pastor JE, Berenguer J, Hidalgo A. Thermostable in vitro transcription-translation compatible with microfluidic droplets. Microb Cell Fact 2024; 23:169. [PMID: 38858677 PMCID: PMC11165818 DOI: 10.1186/s12934-024-02440-y] [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: 11/27/2023] [Accepted: 05/25/2024] [Indexed: 06/12/2024] Open
Abstract
BACKGROUND In vitro expression involves the utilization of the cellular transcription and translation machinery in an acellular context to produce one or more proteins of interest and has found widespread application in synthetic biology and in pharmaceutical biomanufacturing. Most in vitro expression systems available are active at moderate temperatures, but to screen large libraries of natural or artificial genetic diversity for highly thermostable enzymes or enzyme variants, it is instrumental to enable protein synthesis at high temperatures. OBJECTIVES Develop an in vitro expression system operating at high temperatures compatible with enzymatic assays and with technologies that enable ultrahigh-throughput protein expression in reduced volumes, such as microfluidic water-in-oil (w/o) droplets. RESULTS We produced cell-free extracts from Thermus thermophilus for in vitro translation including thermostable enzymatic cascades for energy regeneration and a moderately thermostable RNA polymerase for transcription, which ultimately limited the temperature of protein synthesis. The yield was comparable or superior to other thermostable in vitro expression systems, while the preparation procedure is much simpler and can be suited to different Thermus thermophilus strains. Furthermore, these extracts have enabled in vitro expression in microfluidic droplets at high temperatures for the first time. CONCLUSIONS Cell-free extracts from Thermus thermophilus represent a simpler alternative to heavily optimized or pure component thermostable in vitro expression systems. Moreover, due to their compatibility with droplet microfluidics and enzyme assays at high temperatures, the reported system represents a convenient gateway for enzyme screening at higher temperatures with ultrahigh-throughput.
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Grants
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- BIO-2013-44963-R, RED2022-134755-T, CEX2021-001154-S Ministerio de Ciencia e Innovación
- BIO-2013-44963-R, RED2022-134755-T, CEX2021-001154-S Ministerio de Ciencia e Innovación
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Affiliation(s)
- Ana L J L Ribeiro
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Patricia Pérez-Arnaiz
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Mercedes Sánchez-Costa
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Lara Pérez
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Marcos Almendros
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Liisa van Vliet
- Departament of Biochemistry, Cambridge University, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
- DropTech Ltd, 91 Canterbury Court, Cambridge, CB4 3QU, UK
| | - Fabrice Gielen
- DropTech Ltd, 91 Canterbury Court, Cambridge, CB4 3QU, UK
- Living Systems Institute, Faculty of Health and Life Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Department of Physics and Astronomy, Faculty of Environment, Science and Economy, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
| | - Jesmine Lim
- Prozomix Ltd, Building 4, West End Ind. Estate, Haltwhistle, Northumberland, NE49 9HA, UK
| | - Simon Charnock
- Prozomix Ltd, Building 4, West End Ind. Estate, Haltwhistle, Northumberland, NE49 9HA, UK
| | - Florian Hollfelder
- Departament of Biochemistry, Cambridge University, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - J Eduardo González-Pastor
- Centro de Astrobiología (CAB), CSIC-INTA, Ctra de Torrejón a Ajalvir, Km 4, 28850, Torrejón de Ardoz, Spain
| | - José Berenguer
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Aurelio Hidalgo
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain.
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain.
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain.
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2
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Herrera-Morandé A, Vallejos-Baccelliere G, Cea PA, Zamora RA, Cid D, Maturana P, González-Ordenes F, Castro-Fernández V, Guixé V. Kinetic characterization and phylogenetic analysis of human ADP-dependent glucokinase reveal new insights into its regulatory properties. Arch Biochem Biophys 2023; 741:109602. [PMID: 37084804 DOI: 10.1016/j.abb.2023.109602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/13/2023] [Accepted: 04/17/2023] [Indexed: 04/23/2023]
Abstract
Although ADP-dependent sugar kinases were first described in archaea, at present, the presence of an ADP-dependent glucokinase (ADP-GK) in mammals is well documented. This enzyme is mainly expressed in hematopoietic lineages and tumor tissues, although its role has remained elusive. Here, we report a detailed kinetic characterization of the human ADP-dependent glucokinase (hADP-GK), addressing the influence of a putative signal peptide for endoplasmic reticulum (ER) destination by characterizing a truncated form. The truncated form revealed no significant impact on the kinetic parameters, showing only a slight increase in the Vmax value, higher metal promiscuity, and the same nucleotide specificity as the full-length enzyme. hADP-GK presents an ordered sequential kinetic mechanism in which MgADP is the first substrate to bind and AMP is the last product released, being the same mechanism described for archaeal ADP-dependent sugar kinases, in agreement with the protein topology. Substrate inhibition by glucose was observed due to sugar binding to nonproductive species. Although Mg2+ is an essential component for kinase activity, it also behaves as a partial mixed-type inhibitor for hADP-GK, mainly by decreasing the MgADP affinity. Regarding its distribution, phylogenetic analysis shows that ADP-GK´s are present in a wide diversity of eukaryotic organisms although it is not ubiquitous. Eukaryotic ADP-GKs sequences cluster into two main groups, showing differences in the highly conserved sugar-binding motif reported for archaeal enzymes [NX(N)XD] where a cysteine residue is found instead of asparagine in a significant number of enzymes. Site directed mutagenesis of the cysteine residue by asparagine produces a 6-fold decrease in Vmax, suggesting a role for this residue in the catalytic process, probably by facilitating the proper orientation of the substrate to be phosphorylated.
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Affiliation(s)
- Alejandra Herrera-Morandé
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.
| | - Gabriel Vallejos-Baccelliere
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.
| | - Pablo A Cea
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Ricardo A Zamora
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Dixon Cid
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Pablo Maturana
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Felipe González-Ordenes
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Víctor Castro-Fernández
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Victoria Guixé
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.
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3
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Piedrafita G, Varma SJ, Castro C, Messner CB, Szyrwiel L, Griffin JL, Ralser M. Cysteine and iron accelerate the formation of ribose-5-phosphate, providing insights into the evolutionary origins of the metabolic network structure. PLoS Biol 2021; 19:e3001468. [PMID: 34860829 PMCID: PMC8673631 DOI: 10.1371/journal.pbio.3001468] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 12/15/2021] [Accepted: 11/04/2021] [Indexed: 12/21/2022] Open
Abstract
The structure of the metabolic network is highly conserved, but we know little about its evolutionary origins. Key for explaining the early evolution of metabolism is solving a chicken–egg dilemma, which describes that enzymes are made from the very same molecules they produce. The recent discovery of several nonenzymatic reaction sequences that topologically resemble central metabolism has provided experimental support for a “metabolism first” theory, in which at least part of the extant metabolic network emerged on the basis of nonenzymatic reactions. But how could evolution kick-start on the basis of a metal catalyzed reaction sequence, and how could the structure of nonenzymatic reaction sequences be imprinted on the metabolic network to remain conserved for billions of years? We performed an in vitro screening where we add the simplest components of metabolic enzymes, proteinogenic amino acids, to a nonenzymatic, iron-driven reaction network that resembles glycolysis and the pentose phosphate pathway (PPP). We observe that the presence of the amino acids enhanced several of the nonenzymatic reactions. Particular attention was triggered by a reaction that resembles a rate-limiting step in the oxidative PPP. A prebiotically available, proteinogenic amino acid cysteine accelerated the formation of RNA nucleoside precursor ribose-5-phosphate from 6-phosphogluconate. We report that iron and cysteine interact and have additive effects on the reaction rate so that ribose-5-phosphate forms at high specificity under mild, metabolism typical temperature and environmental conditions. We speculate that accelerating effects of amino acids on rate-limiting nonenzymatic reactions could have facilitated a stepwise enzymatization of nonenzymatic reaction sequences, imprinting their structure on the evolving metabolic network. The evolutionary origins of metabolism are largely unknown. This study shows that the prebiotically available proteinogenic amino acid cysteine can promote the metabolism-like rate-limiting formation of ribose-5-phosphate, suggesting that early metabolic pathways could have emerged thought the stepwise enzymatization of non-enzymatic reaction sequences.
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Affiliation(s)
- Gabriel Piedrafita
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, United Kingdom
| | - Sreejith J. Varma
- Department of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Cecilia Castro
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, United Kingdom
| | - Christoph B. Messner
- The Molecular Biology of Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Lukasz Szyrwiel
- Department of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
- The Molecular Biology of Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Julian L. Griffin
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, United Kingdom
- The Rowett Institute, The University of Aberdeen, Aberdeen, United Kingdom
| | - Markus Ralser
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, United Kingdom
- Department of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
- The Molecular Biology of Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
- * E-mail:
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4
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Moalic Y, Hartunians J, Dalmasso C, Courtine D, Georges M, Oger P, Shao Z, Jebbar M, Alain K. The Piezo-Hyperthermophilic Archaeon Thermococcus piezophilus Regulates Its Energy Efficiency System to Cope With Large Hydrostatic Pressure Variations. Front Microbiol 2021; 12:730231. [PMID: 34803948 PMCID: PMC8595942 DOI: 10.3389/fmicb.2021.730231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 10/13/2021] [Indexed: 11/23/2022] Open
Abstract
Deep-sea ecosystems share a common physical parameter, namely high hydrostatic pressure (HHP). Some of the microorganisms isolated at great depths have a high physiological plasticity to face pressure variations. The adaptive strategies by which deep-sea microorganisms cope with HHP variations remain to be elucidated, especially considering the extent of their biotopes on Earth. Herein, we investigated the gene expression patterns of Thermococcus piezophilus, a piezohyperthermophilic archaeon isolated from the deepest hydrothermal vent known to date, under sub-optimal, optimal and supra-optimal pressures (0.1, 50, and 90 MPa, respectively). At stressful pressures [sub-optimal (0.1 MPa) and supra-optimal (90 MPa) conditions], no classical stress response was observed. Instead, we observed an unexpected transcriptional modulation of more than a hundred gene clusters, under the putative control of the master transcriptional regulator SurR, some of which are described as being involved in energy metabolism. This suggests a fine-tuning effect of HHP on the SurR regulon. Pressure could act on gene regulation, in addition to modulating their expression.
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Affiliation(s)
- Yann Moalic
- Univ Brest, CNRS, Ifremer, Laboratoire de Microbiologie des Environnements Extrêmes LM2E, UMR 6197, IUEM, Plouzané, France.,IRP 1211 MicrobSea, Sino-French Laboratory of Deep-Sea Microbiology, LM2E, Plouzané, France
| | - Jordan Hartunians
- Univ Brest, CNRS, Ifremer, Laboratoire de Microbiologie des Environnements Extrêmes LM2E, UMR 6197, IUEM, Plouzané, France.,IRP 1211 MicrobSea, Sino-French Laboratory of Deep-Sea Microbiology, LM2E, Plouzané, France
| | - Cécile Dalmasso
- Univ Brest, CNRS, Ifremer, Laboratoire de Microbiologie des Environnements Extrêmes LM2E, UMR 6197, IUEM, Plouzané, France.,IRP 1211 MicrobSea, Sino-French Laboratory of Deep-Sea Microbiology, LM2E, Plouzané, France
| | - Damien Courtine
- Univ Brest, CNRS, Ifremer, Laboratoire de Microbiologie des Environnements Extrêmes LM2E, UMR 6197, IUEM, Plouzané, France.,IRP 1211 MicrobSea, Sino-French Laboratory of Deep-Sea Microbiology, LM2E, Plouzané, France
| | - Myriam Georges
- Univ Brest, CNRS, Ifremer, Laboratoire de Microbiologie des Environnements Extrêmes LM2E, UMR 6197, IUEM, Plouzané, France.,IRP 1211 MicrobSea, Sino-French Laboratory of Deep-Sea Microbiology, LM2E, Plouzané, France
| | - Philippe Oger
- Université de Lyon, INSA Lyon, CNRS UMR 5240, Villeurbanne, France
| | - Zongze Shao
- IRP 1211 MicrobSea, Sino-French Laboratory of Deep-Sea Microbiology, LM2E, Plouzané, France.,Key Laboratory of Marine Biogenetic Resources, The Third Institute of Oceanography SOA, Xiamen, China
| | - Mohamed Jebbar
- Univ Brest, CNRS, Ifremer, Laboratoire de Microbiologie des Environnements Extrêmes LM2E, UMR 6197, IUEM, Plouzané, France.,IRP 1211 MicrobSea, Sino-French Laboratory of Deep-Sea Microbiology, LM2E, Plouzané, France
| | - Karine Alain
- Univ Brest, CNRS, Ifremer, Laboratoire de Microbiologie des Environnements Extrêmes LM2E, UMR 6197, IUEM, Plouzané, France.,IRP 1211 MicrobSea, Sino-French Laboratory of Deep-Sea Microbiology, LM2E, Plouzané, France
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Obulisamy PK, Mehariya S. Polyhydroxyalkanoates from extremophiles: A review. BIORESOURCE TECHNOLOGY 2021; 325:124653. [PMID: 33465644 DOI: 10.1016/j.biortech.2020.124653] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/27/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
Polyhydroxyalkanoates (PHAs) are group monomers/heteropolymers that are biodegradable and widely used in biomedical applications. They are considered as alternatives to fossil derived polymers and accumulated by microbes including extremophilic archaea as energy storage inclusions under nutrient limitations. The use of extremophilic archaea for PHA production is an economically viable option for conventional aerobic processes, but less is known about their pathways and PHA accumulation capacities. This review summarized: (a) specific adaptive mechanisms towards extreme environments by extremophiles and specific role of PHAs; (b) understanding of PHA synthesis/metabolism in archaea and specific functional genes; (c) genetic engineering and process engineering approaches required for high-rate PHA production using extremophilic archaea. To conclude, the future studies are suggested to understand the membrane lipids and PHAs accumulation to explain the adaptation mechanism of extremophiles and exploiting it for commercial production of PHAs.
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Affiliation(s)
| | - Sanjeet Mehariya
- Department of Engineering, University of Campania "Luigi Vanvitelli", Real Casa dell'Annunziata, Italy
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6
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Green Production and Biotechnological Applications of Cell Wall Lytic Enzymes. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9235012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
: Energy demand is constantly growing, and, nowadays, fossil fuels still play a dominant role in global energy production, despite their negative effects on air pollution and the emission of greenhouse gases, which are the main contributors to global warming. An alternative clean source of energy is represented by the lignocellulose fraction of plant cell walls, the most abundant carbon source on Earth. To obtain biofuels, lignocellulose must be efficiently converted into fermentable sugars. In this regard, the exploitation of cell wall lytic enzymes (CWLEs) produced by lignocellulolytic fungi and bacteria may be considered as an eco-friendly alternative. These organisms evolved to produce a variety of highly specific CWLEs, even if in low amounts. For an industrial use, both the identification of novel CWLEs and the optimization of sustainable CWLE-expressing biofactories are crucial. In this review, we focus on recently reported advances in the heterologous expression of CWLEs from microbial and plant expression systems as well as some of their industrial applications, including the production of biofuels from agricultural feedstock and of value-added compounds from waste materials. Moreover, since heterologous expression of CWLEs may be toxic to plant hosts, genetic strategies aimed in converting such a deleterious effect into a beneficial trait are discussed.
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7
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Abstract
Metabolomics is valuable for studying microbial metabolism, which is often used to elucidate biological functions. Effective application of metabolomics is enhanced by fundamental understanding of microbial physiology and metabolism. This review briefly highlights important aspects of metabolism that are essential for designing and executing effective metabolic and metabolomics studies. The influence of microbial physiology and metabolism on growth, energy metabolism and regulation is briefly reviewed. The chapter also evaluates factors affecting metabolic prediction.
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Affiliation(s)
- Chijioke J Joshua
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Joint BioEnergy Institute, Emeryville, CA, USA.
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8
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Genome Analysis of Endomicrobium proavitum Suggests Loss and Gain of Relevant Functions during the Evolution of Intracellular Symbionts. Appl Environ Microbiol 2017. [PMID: 28646115 DOI: 10.1128/aem.00656-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial endosymbionts of eukaryotes show progressive genome erosion, but detailed investigations of the evolutionary processes involved in the transition to an intracellular lifestyle are generally hampered by the lack of extant free-living lineages. Here, we characterize the genome of the recently isolated, free-living Endomicrobium proavitum, the second member of the Elusimicrobia phylum brought into pure culture, and compare it to the closely related "Candidatus Endomicrobium trichonymphae" strain Rs-D17, a previously described but uncultured endosymbiont of termite gut flagellates. A reconstruction of the metabolic pathways of Endomicrobium proavitum matched the fermentation products formed in pure culture and underscored its restriction to glucose as the substrate. However, several pathways present in the free-living strain, e.g., for the uptake and activation of glucose and its subsequent fermentation, ammonium assimilation, and outer membrane biogenesis, were absent or disrupted in the endosymbiont, probably lost during the massive genome rearrangements that occurred during symbiogenesis. While the majority of the genes in strain Rs-D17 have orthologs in Endomicrobium proavitum, the endosymbiont also possesses a number of functions that are absent from the free-living strain and may represent adaptations to the intracellular lifestyle. Phylogenetic analysis revealed that the genes encoding glucose 6-phosphate and amino acid transporters, acetaldehyde/alcohol dehydrogenase, and the pathways of glucuronic acid catabolism and thiamine pyrophosphate biosynthesis were either acquired by horizontal gene transfer or may represent ancestral traits that were lost in the free-living strain. The polyphyletic origin of Endomicrobia in different flagellate hosts makes them excellent models for future studies of convergent and parallel evolution during symbiogenesis.IMPORTANCE The isolation of a free-living relative of intracellular symbionts provides the rare opportunity to identify the evolutionary processes that occur in the course of symbiogenesis. Our study documents that the genome of "Candidatus Endomicrobium trichonymphae," which represents a clade of endosymbionts that have coevolved with termite gut flagellates for more than 40 million years, is not simply a subset of the genes present in Endomicrobium proavitum, a member of the ancestral, free-living lineage. Rather, comparative genomics revealed that the endosymbionts possess several relevant functions that were either prerequisites for colonization of the intracellular habitat or might have served to compensate for genes losses that occurred during genome erosion. Some gene sets found only in the endosymbiont were apparently acquired by horizontal transfer from other gut bacteria, which suggests that the intracellular bacteria of flagellates are not entirely cut off from gene flow.
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9
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Sekar N, Wu C, Adams MW, Ramasamy RP. Electricity generation by
Pyrococcus furiosus
in microbial fuel cells operated at 90°C. Biotechnol Bioeng 2017; 114:1419-1427. [DOI: 10.1002/bit.26271] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 02/14/2017] [Accepted: 02/16/2017] [Indexed: 02/04/2023]
Affiliation(s)
- Narendran Sekar
- Nano Electrochemistry Laboratory, College of EngineeringUniversity of GeorgiaAthensGeorgia30602
| | - Chang‐Hao Wu
- Department of Biochemistry and Molecular BiologyUniversity of GeorgiaAthensGeorgia30602
| | - Michael W.W. Adams
- Department of Biochemistry and Molecular BiologyUniversity of GeorgiaAthensGeorgia30602
| | - Ramaraja P. Ramasamy
- Nano Electrochemistry Laboratory, College of EngineeringUniversity of GeorgiaAthensGeorgia30602
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10
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Keller MW, Lipscomb GL, Nguyen DM, Crowley AT, Schut GJ, Scott I, Kelly RM, Adams MWW. Ethanol production by the hyperthermophilic archaeon Pyrococcus furiosus by expression of bacterial bifunctional alcohol dehydrogenases. Microb Biotechnol 2017; 10:1535-1545. [PMID: 28194879 PMCID: PMC5658578 DOI: 10.1111/1751-7915.12486] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 10/03/2016] [Accepted: 11/14/2016] [Indexed: 01/25/2023] Open
Abstract
Ethanol is an important target for the renewable production of liquid transportation fuels. It can be produced biologically from pyruvate, via pyruvate decarboxylase, or from acetyl‐CoA, by alcohol dehydrogenase E (AdhE). Thermophilic bacteria utilize AdhE, which is a bifunctional enzyme that contains both acetaldehyde dehydrogenase and alcohol dehydrogenase activities. Many of these organisms also contain a separate alcohol dehydrogenase (AdhA) that generates ethanol from acetaldehyde, although the role of AdhA in ethanol production is typically not clear. As acetyl‐CoA is a key central metabolite that can be generated from a wide range of substrates, AdhE can serve as a single gene fuel module to produce ethanol through primary metabolic pathways. The focus here is on the hyperthermophilic archaeon Pyrococcus furiosus, which grows by fermenting sugar to acetate, CO2 and H2. Previously, by the heterologous expression of adhA from a thermophilic bacterium, P. furiosus was shown to produce ethanol by a novel mechanism from acetate, mediated by AdhA and the native enzyme aldehyde oxidoreductase (AOR). In this study, the AOR gene was deleted from P. furiosus to evaluate ethanol production directly from acetyl‐CoA by heterologous expression of the adhE gene from eight thermophilic bacteria. Only AdhEs from two Thermoanaerobacter strains showed significant activity in cell‐free extracts of recombinant P. furiosus and supported ethanol production in vivo. In the AOR deletion background, the highest amount of ethanol (estimated 61% theoretical yield) was produced when adhE and adhA from Thermoanaerobacter were co‐expressed.
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Affiliation(s)
- Matthew W Keller
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Gina L Lipscomb
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Diep M Nguyen
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Alexander T Crowley
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Gerrit J Schut
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Israel Scott
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Robert M Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
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Zhang X, Chen M, Liang Y, Xing Y, Yang L, Chen M, Comstock JC, Li Y, Yang L. Morphological and Physiological Responses of Sugarcane to Leifsonia xyli subsp. xyli Infection. PLANT DISEASE 2016; 100:2499-2506. [PMID: 30686166 DOI: 10.1094/pdis-10-15-1134-re] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Ratoon stunt, caused by the bacterium Leifsonia xyli subsp. xyli, is one of the major sugarcane diseases worldwide. The objectives of this study were to determine the variation in morphology and DNA sequence of L. xyli subsp. xyli strains isolated in China, to compare the changes that occurred in vascular ultrastructure and levels of endogenous hormone abscisic acid (ABA), auxins (indoleacetic acid [IAA]), and gibberellic acids (GA3) in sugarcane stalks. Experiments were also conducted with two sugarcane varieties, 'ROC22' and 'Badila', in the greenhouse to understand the cytological and physiological mechanisms of L. xyli subsp. xyli-induced growth stunting. There were three treatments in the experiments: (i) healthy plants (L. xyli subsp. xyli-free plants), (ii) infected plants (L. xyli subsp. xyli-infected seedcanes treated with hot water, and (iii) infected plants (healthy seedcanes dipped in L. xyli subsp. xyli cell culture). The results showed that sequence coverage of a locally isolated strain, LxxGXBZ01, was 99.99%, and the average nucleotide identity between LxxGXBZ01 and the other well-characterized Brazilian isolate LxxCTCB07 was 93.61%. LxxGXBZ01 occurred in different sizes and shapes in xylem vessels of infected plants. In comparison with healthy stalks, the secondary walls of the vessel element in L. xyli subsp. xyli-infected stalks were degraded with uneven wall thickness, deformities, sticky substances, and electron-dense substances accumulated inside the cells. Compared with the healthy and hot-water treatments, the contents of IAA and GA3 were significantly lower, while that of ABA was significantly higher in the L. xyli subsp. xyli-infected stalks. The information obtained in this study will expand our understanding of ratoon stunt etiology and cytological and physiological bases of the disease manifestation.
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Affiliation(s)
- Xiaoqiu Zhang
- Agricultural College, State Key Laboratory of Subtropical Bioresources Conservation and Utilization, Guangxi University, Nanning 530005, China
| | - Minghui Chen
- Agricultural College, State Key Laboratory of Subtropical Bioresources Conservation and Utilization, Guangxi University, Nanning 530005, China
| | - Yongjian Liang
- Agricultural College, State Key Laboratory of Subtropical Bioresources Conservation and Utilization, Guangxi University, Nanning 530005, China
| | - Yongxiu Xing
- Agricultural College, State Key Laboratory of Subtropical Bioresources Conservation and Utilization, Guangxi University, Nanning 530005, China
| | - Litao Yang
- Agricultural College, State Key Laboratory of Subtropical Bioresources Conservation and Utilization, Guangxi University, Nanning 530005, China
| | - Minghui Chen
- Ping Ding Shan University, Pingdingshan, Henan 46700, China
| | | | - Yangrui Li
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Sugarcane Research Center, Chinese Academy of Agricultural Sciences; Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China
| | - Litao Yang
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Sugarcane Research Center, Chinese Academy of Agricultural Sciences; Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China
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12
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Analysis of the complete genome sequence of the archaeon Pyrococcus chitonophagus DSM 10152 (formerly Thermococcus chitonophagus). Extremophiles 2016; 20:351-61. [DOI: 10.1007/s00792-016-0826-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/15/2016] [Indexed: 10/22/2022]
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Ciranna A, Pawar SS, Santala V, Karp M, van Niel EWJ. Assessment of metabolic flux distribution in the thermophilic hydrogen producer Caloramator celer as affected by external pH and hydrogen partial pressure. Microb Cell Fact 2014; 13:48. [PMID: 24678972 PMCID: PMC3986597 DOI: 10.1186/1475-2859-13-48] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 03/18/2014] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Caloramator celer is a strict anaerobic, alkalitolerant, thermophilic bacterium capable of converting glucose to hydrogen (H2), carbon dioxide, acetate, ethanol and formate by a mixed acid fermentation. Depending on the growth conditions C. celer can produce H2 at high yields. For a biotechnological exploitation of this bacterium for H2 production it is crucial to understand the factors that regulate carbon and electron fluxes and therefore the final distribution of metabolites to channel the metabolic flux towards the desired product. RESULTS Combining experimental results from batch fermentations with genome analysis, reconstruction of central carbon metabolism and metabolic flux analysis (MFA), this study shed light on glucose catabolism of the thermophilic alkalitolerant bacterium C. celer. Two innate factors pertaining to culture conditions have been identified to significantly affect the metabolic flux distribution: culture pH and partial pressures of H2 (PH2). Overall, at alkaline to neutral pH the rate of biomass synthesis was maximized, whereas at acidic pH the lower growth rate and the less efficient biomass formation are accompanied with more efficient energy recovery from the substrate indicating high cell maintenance possibly to sustain intracellular pH homeostasis. Higher H2 yields were associated with fermentation at acidic pH as a consequence of the lower synthesis of other reduced by-products such as formate and ethanol. In contrast, PH2 did not affect the growth of C. celer on glucose. At high PH2 the cellular redox state was balanced by rerouting the flow of carbon and electrons to ethanol and formate production allowing unaltered glycolytic flux and growth rate, but resulting in a decreased H2 synthesis. CONCLUSION C. celer possesses a flexible fermentative metabolism that allows redistribution of fluxes at key metabolic nodes to simultaneously control redox state and efficiently harvest energy from substrate even under unfavorable conditions (i.e. low pH and high PH2). With the H2 production in mind, acidic pH and low PH2 should be preferred for a high yield-oriented process, while a high productivity-oriented process can be achieved at alkaline pH and high PH2.
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Affiliation(s)
- Alessandro Ciranna
- Department of Chemistry and Bioengineering, Tampere University of Technology, Korkeakoulunkatu 8, FI-33720 Tampere, Finland
| | - Sudhanshu S Pawar
- Department of Applied Microbiology, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
| | - Ville Santala
- Department of Chemistry and Bioengineering, Tampere University of Technology, Korkeakoulunkatu 8, FI-33720 Tampere, Finland
| | - Matti Karp
- Department of Chemistry and Bioengineering, Tampere University of Technology, Korkeakoulunkatu 8, FI-33720 Tampere, Finland
| | - Ed WJ van Niel
- Department of Applied Microbiology, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
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Gogliettino M, Riccio A, Cocca E, Rossi M, Palmieri G, Balestrieri M. A new pepstatin-insensitive thermopsin-like protease overproduced in peptide-rich cultures of Sulfolobus solfataricus. Int J Mol Sci 2014; 15:3204-19. [PMID: 24566144 PMCID: PMC3958906 DOI: 10.3390/ijms15023204] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 01/26/2014] [Accepted: 02/11/2014] [Indexed: 11/16/2022] Open
Abstract
In this study, we gain insight into the extracellular proteolytic system of Sulfolobus solfataricus grown on proteinaceous substrates, providing further evidence that acidic proteases were specifically produced in response to peptide-rich media. The main proteolytic component was the previously isolated SsMTP (Sulfolobus solfataricus multi-domain thermopsin-like protease), while the less abundant (named SsMTP-1) one was purified, characterized and identified as the sso1175 gene-product. The protein revealed a multi-domain organization shared with the cognate SsMTP with a catalytic domain followed by several tandemly-repeated motifs. Moreover, both enzymes were found spread across the Crenarchaeota phylum and belonging to the thermopsin family, although segregated into diverse phylogenetic clusters. SsMTP-1 showed a 75-kDa molecular mass and was stable in the temperature range 50–90 °C, with optimal activity at 70 °C and pH 2.0. Serine, metallo and aspartic protease inhibitors did not affect the enzyme activity, designating SsMTP-1 as a new member of the pepstatin-insensitive aspartic protease family. The peptide-bond-specificity of SsMTP-1 in the cleavage of the oxidized insulin B chain was uncommon amongst thermopsins, suggesting that it could play a distinct, but cooperative role in the protein degradation machinery. Interestingly, predictions of the transmembrane protein topology of SsMTP and SsMTP-1 strongly suggest a possible contribution in signal-transduction pathways.
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Affiliation(s)
- Marta Gogliettino
- Institute of Biosciences and BioResources, National Research Council (CNR-IBBR), Via Pietro Castellino 111, Naples 80131, Italy.
| | - Alessia Riccio
- Institute of Biosciences and BioResources, National Research Council (CNR-IBBR), Via Pietro Castellino 111, Naples 80131, Italy.
| | - Ennio Cocca
- Institute of Biosciences and BioResources, National Research Council (CNR-IBBR), Via Pietro Castellino 111, Naples 80131, Italy.
| | - Mosè Rossi
- Institute of Biosciences and BioResources, National Research Council (CNR-IBBR), Via Pietro Castellino 111, Naples 80131, Italy.
| | - Gianna Palmieri
- Institute of Biosciences and BioResources, National Research Council (CNR-IBBR), Via Pietro Castellino 111, Naples 80131, Italy.
| | - Marco Balestrieri
- Institute of Biosciences and BioResources, National Research Council (CNR-IBBR), Via Pietro Castellino 111, Naples 80131, Italy.
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Tong W, Chen Z, Cao Z, Wang Q, Zhang J, Bai X, Wang R, Liu S. Robustness analysis of a constraint-based metabolic model links cell growth and proteomics of Thermoanaerobacter tengcongensis under temperature perturbation. MOLECULAR BIOSYSTEMS 2013; 9:713-22. [PMID: 23396507 DOI: 10.1039/c3mb25278g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The integration of omic data with metabolic networks has been demonstrated to be an effective approach to elucidate the underlying metabolic mechanisms in life. Because the metabolic pathways of Thermoanaerobacter tengcongensis (T. tengcongensis) are incomplete, we used a 1-(13)C-glucose culture to monitor intracellular isotope-labeled metabolites by GC/MS and identified the gap gene in glucose catabolism, Re-citrate synthase. Based on genome annotation and biochemical information, we reconstructed the metabolic network of glucose metabolism and amino acid synthesis in T. tengcongensis, including 253 reactions, 227 metabolites, and 236 genes. Furthermore, we performed constraint based modeling (CBM)-derived robustness analysis on the model to study the dynamic changes of the metabolic network. By perturbing the culture temperature from 75 to 55 °C, we collected the bacterial growth rates and differential proteomes. Assuming that protein abundance changes represent metabolic flux variations, we proposed that the robustness analysis of the CBM model could decipher the effect of proteome change on the bacterial growth under perturbation. For approximately 73% of the reactions, the predicted cell growth changes due to such reaction flux variations matched the observed cell growth data. Our study, therefore, indicates that differential proteome data can be integrated with metabolic network modeling and that robustness analysis is a strong method for representing the dynamic change in cell phenotypes under perturbation.
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Affiliation(s)
- Wei Tong
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 101300, China
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Schut GJ, Boyd ES, Peters JW, Adams MWW. The modular respiratory complexes involved in hydrogen and sulfur metabolism by heterotrophic hyperthermophilic archaea and their evolutionary implications. FEMS Microbiol Rev 2012; 37:182-203. [PMID: 22713092 DOI: 10.1111/j.1574-6976.2012.00346.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 05/30/2012] [Accepted: 06/08/2012] [Indexed: 12/01/2022] Open
Abstract
Hydrogen production is a vital metabolic process for many anaerobic organisms, and the enzyme responsible, hydrogenase, has been studied since the 1930s. A novel subfamily with unique properties was recently recognized, represented by the 14-subunit membrane-bound [NiFe] hydrogenase from the archaeon Pyrococcus furiosus. This so-called energy-converting hydrogenase links the thermodynamically favorable oxidation of ferredoxin with the formation of hydrogen and conserves energy in the form of an ion gradient. It is therefore a simple respiratory system within a single complex. This hydrogenase shows a modular composition represented by a Na(+)/H(+) antiporter domain (Mrp) and a [NiFe] hydrogenase domain (Mbh). An analysis of the large number of microbial genome sequences available shows that homologs of Mbh and Mrp tend to be clustered within the genomes of a limited number of archaeal and bacterial species. In several instances, additional genes are associated with the Mbh and Mrp gene clusters that encode proteins that catalyze the oxidation of formate, CO or NAD(P)H. The Mbh complex also shows extensive homology to a number of subunits within the NADH quinone oxidoreductase or complex I family. The respiratory-type membrane-bound hydrogenase complex appears to be closely related to the common ancestor of complex I and [NiFe] hydrogenases in general.
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Affiliation(s)
- Gerrit J Schut
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, USA
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Abreu AA, Karakashev D, Angelidaki I, Sousa DZ, Alves MM. Biohydrogen production from arabinose and glucose using extreme thermophilic anaerobic mixed cultures. BIOTECHNOLOGY FOR BIOFUELS 2012; 5:6. [PMID: 22330180 PMCID: PMC3298801 DOI: 10.1186/1754-6834-5-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 02/13/2012] [Indexed: 05/26/2023]
Abstract
BACKGROUND Second generation hydrogen fermentation technologies using organic agricultural and forestry wastes are emerging. The efficient microbial fermentation of hexoses and pentoses resulting from the pretreatment of lingocellulosic materials is essential for the success of these processes. RESULTS Conversion of arabinose and glucose to hydrogen, by extreme thermophilic, anaerobic, mixed cultures was studied in continuous (70°C, pH 5.5) and batch (70°C, pH 5.5 and pH 7) assays. Two expanded granular sludge bed (EGSB) reactors, Rarab and Rgluc, were continuously fed with arabinose and glucose, respectively. No significant differences in reactor performance were observed for arabinose and glucose organic loading rates (OLR) ranging from 4.3 to 7.1 kgCOD m-3 d-1. However, for an OLR of 14.2 kgCOD m-3 d-1, hydrogen production rate and hydrogen yield were higher in Rarab than in Rgluc (average hydrogen production rate of 3.2 and 2.0 LH2 L-1 d-1 and hydrogen yield of 1.10 and 0.75 molH2 mol-1substrate for Rarab and Rgluc, respectively). Lower hydrogen production in Rgluc was associated with higher lactate production. Denaturing gradient gel electrophoresis (DGGE) results revealed no significant difference on the bacterial community composition between operational periods and between the reactors. Increased hydrogen production was observed in batch experiments when hydrogen partial pressure was kept low, both with arabinose and glucose as substrate. Sugars were completely consumed and hydrogen production stimulated (62% higher) when pH 7 was used instead of pH 5.5. CONCLUSIONS Continuous hydrogen production rate from arabinose was significantly higher than from glucose, when higher organic loading rate was used. The effect of hydrogen partial pressure on hydrogen production from glucose in batch mode was related to the extent of sugar utilization and not to the efficiency of substrate conversion to hydrogen. Furthermore, at pH 7.0, sugars uptake, hydrogen production and yield were higher than at pH 5.5, with both arabinose and glucose as substrates.
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Affiliation(s)
- Angela A Abreu
- Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet 115, DK-2800, Kgs Lyngby, Denmark
| | - Dimitar Karakashev
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet 115, DK-2800, Kgs Lyngby, Denmark
| | - Irini Angelidaki
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet 115, DK-2800, Kgs Lyngby, Denmark
| | - Diana Z Sousa
- Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - M Madalena Alves
- Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
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18
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Rinker K, Han C, Kelly R. Continuous culture as a tool for investigating the growth physiology of heterotrophic hyperthermophiles and extreme thermoacidophiles. J Appl Microbiol 2010; 85 Suppl 1:118S-127S. [DOI: 10.1111/j.1365-2672.1998.tb05290.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Herbel Z, Rákhely G, Bagi Z, Ivanova G, Acs N, Kovács E, Kovács KL. Exploitation of the extremely thermophilic Caldicellulosiruptor saccharolyticus in hydrogen and biogas production from biomasses. ENVIRONMENTAL TECHNOLOGY 2010; 31:1017-24. [PMID: 20662389 DOI: 10.1080/09593330.2010.484075] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Caldicellulosiruptor saccharolyticus has attracted considerable attention by virtue of its ability to degrade various polysaccharide, oligosaccharide and monosaccharide substrates at temperatures above 70 degrees C, while its ability to convert various sugars to hydrogen has led to C. saccharolyticus being selected for the fermentative production of hydrogen. In this study, the utilization of a pure cellulosic substrate and mixed biomasses of plant origin was investigated. Cellulase biosynthesis can be triggered by growing cells on various monomeric carbohydrates, e.g. glucose or fructose. Pretreatment with cellulase-producing Bacilli improves the hydrogen yield, indicating that C. saccharolyticus alone can only partially decompose cellulosic substrates. The hydrogen-producing activity of C. saccharolyticus can be exploited in biogas technologies. With appropriate induction of the polymer-degrading enzymes, C. saccharolyticus may become a prime candidate with which to improve the yield and efficacy of practical hydrogen- and biogas-producing processes.
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Affiliation(s)
- Zsófia Herbel
- Department of Biotechnology, University of Szeged, H-6726 Szeged, Kozepfasor 52, Hungary
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Verhaart MRA, Bielen AAM, van der Oost J, Stams AJM, Kengen SWM. Hydrogen production by hyperthermophilic and extremely thermophilic bacteria and archaea: mechanisms for reductant disposal. ENVIRONMENTAL TECHNOLOGY 2010; 31:993-1003. [PMID: 20662387 DOI: 10.1080/09593331003710244] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Hydrogen produced from biomass by bacteria and archaea is an attractive renewable energy source. However, to make its application more feasible, microorganisms are needed with high hydrogen productivities. For several reasons, hyperthermophilic and extremely thermophilic bacteria and archaea are promising is this respect. In addition to the high polysaccharide-hydrolysing capacities of many of these organisms, an important advantage is their ability to use most of the reducing equivalents (e.g. NADH, reduced ferredoxin) formed during glycolysis for the production of hydrogen, enabling H2/hexose ratios of between 3.0 and 4.0. So, despite the fact that the hydrogen-yielding reactions, especially the one from NADH, are thermodynamically unfavourable, high hydrogen yields are obtained. In this review we focus on three different mechanisms that are employed by a few model organisms, viz. Caldicellulosiruptor saccharolyticus and Thermoanaerobacter tengcongensis, Thermotoga maritima, and Pyrococcus furiosus, to efficiently produce hydrogen. In addition, recent developments to improve hydrogen production by hyperthermophilic and extremely thermophilic bacteria and archaea are discussed.
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Affiliation(s)
- Marcel R A Verhaart
- Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, The Netherlands
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A highly selective oligopeptide binding protein from the archaeon Sulfolobus solfataricus. J Bacteriol 2010; 192:3123-31. [PMID: 20382765 DOI: 10.1128/jb.01414-09] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
SSO1273 of Sulfolobus solfataricus was identified as a cell surface-bound protein by a proteomics approach. Sequence inspection of the genome revealed that the open reading frame of sso1273 is associated in an operon-like structure with genes encoding all the remaining components of a canonical protein-dependent ATP-binding cassette (ABC) transporter. sso1273 gene expression and SSO1273 protein accumulation on the cell surface were demonstrated to be strongly induced by the addition of a peptide mixture (tryptone) to the culture medium. The native protein was obtained in multimeric form, mostly hexameric, under the purification conditions used, and it was characterized as an oligopeptide binding protein, named S. solfataricus OppA (OppA(Ss)). OppaA(Ss) possesses typical sequence patterns required for glycosylphosphatidylinositol lipid anchoring, resulting in an N-linked glycoprotein with carbohydrate moieties likely composed of high mannose and/or hybrid complex carbohydrates. OppA(Ss) specifically binds oligopeptides and shows a marked selectivity for the amino acid composition of substrates when assayed in complex peptide mixtures. Moreover, a truncated version of OppA(Ss), produced in recombinant form and including the putative binding domain, showed a low but significant oligopeptide binding activity.
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Blank CE. Phylogenomic dating--the relative antiquity of archaeal metabolic and physiological traits. ASTROBIOLOGY 2009; 9:193-219. [PMID: 19371161 DOI: 10.1089/ast.2008.0248] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Ancestral trait reconstruction was used to identify the relative ancestry of metabolic and physiological traits in the archaeal domain of life. First, well-resolved phylogenetic trees were inferred with multiple gene sequences obtained from whole genome sequences. Next, metabolic and physiological traits were coded into characters, and ancestral state reconstruction was used to identify ancient and derived traits. Traits inferred to be ancient included sulfur reduction, methanogenesis, and hydrogen oxidation. By using the articulation of the "oxygen age constraint," several other traits were inferred to have arisen at or after 2.32 Ga: aerobic respiration, nitrate reduction, sulfate reduction, thiosulfate reduction, sulfur oxidation, and sulfide oxidation. Complex organic metabolism appeared to be nearly as ancient as autotrophy. Hyperthermophily was ancestral, while hyperacidophily and extreme halophily likely arose after 2.32 Ga. The ancestral euryarchaeote was inferred to have been a hyperthermophilic marine methanogen that lived in a deep-sea hydrothermal vent. In contrast, the ancestral crenarchaeote was most likely a hyperthermophilic sulfur reducer that lived in a slightly acidic terrestrial environment, perhaps a fumarole. Cross-colonization of these habitats may not have occurred until after 2.32 Ga, which suggests that both archaeal lineages exhibited niche specialization on early Earth for a protracted period of time.
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Affiliation(s)
- Carrine E Blank
- Department of Geosciences, University of Montana, Missoula, Montana 59808-1296, USA.
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Chou CJ, Jenney FE, Adams MW, Kelly RM. Hydrogenesis in hyperthermophilic microorganisms: Implications for biofuels. Metab Eng 2008; 10:394-404. [DOI: 10.1016/j.ymben.2008.06.007] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Accepted: 06/20/2008] [Indexed: 11/25/2022]
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Takács M, Tóth A, Bogos B, Varga A, Rákhely G, Kovács KL. Formate hydrogenlyase in the hyperthermophilic archaeon, Thermococcus litoralis. BMC Microbiol 2008; 8:88. [PMID: 18522724 PMCID: PMC2432063 DOI: 10.1186/1471-2180-8-88] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2007] [Accepted: 06/03/2008] [Indexed: 12/02/2022] Open
Abstract
Background Thermococcus litoralis is a heterotrophic facultative sulfur dependent hyperthermophilic Archaeon, which was isolated from a shallow submarine thermal spring. It has been successfully used in a two-stage fermentation system, where various keratinaceous wastes of animal origin were converted to biohydrogen. In this system T. litoralis performed better than its close relative, P. furiosus. Therefore, new alternative enzymes involved in peptide and hydrogen metabolism were assumed in T. litoralis. Results An about 10.5 kb long genomic region was isolated and sequenced from Thermococcus litoralis. In silico analysis revealed that the region contained a putative operon consisting of eight genes: the fdhAB genes coding for a formate dehydrogenase and the mhyCDEFGH genes encoding a [NiFe] hydrogenase belonging to the group of the H2-evolving, energy-conserving, membrane-bound hydrogenases. Reverse transcription linked quantitative Real-Time PCR and Western blotting experiments showed that the expression of the fdh-mhy operon was up-regulated during fermentative growth on peptides and down-regulated in cells cultivated in the presence of sulfur. Immunoblotting and protein separation experiments performed on cell fractions indicated that the formate dehydrogenase part of the complex is associated to the membrane-bound [NiFe] hydrogenase. Conclusion The formate dehydrogenase together with the membrane-bound [NiFe] hydrogenase formed a formate hydrogenlyase (formate dehydrogenase coupled hydrogenase, FDH-MHY) complex. The expression data suggested that its physiological role is linked to the removal of formate likely generated during anaerobic peptide fermentation.
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Affiliation(s)
- Mária Takács
- Department of Biotechnology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
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VanFossen AL, Lewis DL, Nichols JD, Kelly RM. Polysaccharide Degradation and Synthesis by Extremely Thermophilic Anaerobes. Ann N Y Acad Sci 2008; 1125:322-37. [DOI: 10.1196/annals.1419.017] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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26
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Liu D, Zeng RJ, Angelidaki I. Effects of pH and hydraulic retention time on hydrogen production versus methanogenesis during anaerobic fermentation of organic household solid waste under extreme-thermophilic temperature (70°C). Biotechnol Bioeng 2008; 100:1108-14. [DOI: 10.1002/bit.21834] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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de Vrije T, Mars AE, Budde MAW, Lai MH, Dijkema C, de Waard P, Claassen PAM. Glycolytic pathway and hydrogen yield studies of the extreme thermophile Caldicellulosiruptor saccharolyticus. Appl Microbiol Biotechnol 2007; 74:1358-67. [PMID: 17216445 DOI: 10.1007/s00253-006-0783-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Revised: 11/27/2006] [Accepted: 11/28/2006] [Indexed: 10/23/2022]
Abstract
NMR analysis of (13)C-labelling patterns showed that the Embden-Meyerhof (EM) pathway is the main route for glycolysis in the extreme thermophile Caldicellulosiruptor saccharolyticus. Glucose fermentation via the EM pathway to acetate results in a theoretical yield of 4 mol of hydrogen and 2 mol of acetate per mole of glucose. Previously, approximately 70% of the theoretical maximum hydrogen yield has been reached in batch fermentations. In this study, hydrogen and acetate yields have been determined at different dilution rates during continuous cultivation. The yields were dependent on the growth rate. The highest hydrogen yields of 82 to 90% of theoretical maximum (3.3 to 3.6 mol H(2) per mol glucose) were obtained at low growth rates when a relatively larger part of the consumed glucose is used for maintenance. The hydrogen productivity showed the opposite effect. Both the specific and the volumetric hydrogen production rates were highest at the higher growth rates, reaching values of respectively 30 mmol g(-1) h(-1) and 20 mmol l(-1) h(-1). An industrial process for biohydrogen production will require a bioreactor design, which enables an optimal mix of high productivity and high yield.
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Affiliation(s)
- T de Vrije
- Agrotechnology and Food Sciences Group, Wageningen UR, PO Box 17, 6700 AA Wageningen, The Netherlands.
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Kamrat T, Nidetzky B. Entrapment in E. coli improves the operational stability of recombinant β-glycosidase CelB from Pyrococcus furiosus and facilitates biocatalyst recovery. J Biotechnol 2007; 129:69-76. [PMID: 17212972 DOI: 10.1016/j.jbiotec.2006.11.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Revised: 07/07/2006] [Accepted: 07/18/2006] [Indexed: 11/16/2022]
Abstract
beta-Glycosidase CelB from the hyperthermophilic archaeon Pyrococcus furiosus is a versatile biocatalyst that has been used for the hydrolysis and synthesis of beta-d-glycosidic compounds at high temperatures and in non-conventional solvents. In spite of its outstanding thermal stability, CelB is prone to inactivation in the presence of reducing sugars and through recirculation in loop enzyme reactors. Entrapment into E. coli cells was used here to improve the stability of recombinant CelB under conditions promoting strong inactivation. Glutardialdehyde-mediated protein cross-linking or rigidification of the cell membrane by adding magnesium ions was required to prevent release of CelB from within the cell into the bulk solution. In the presence of 1M glucose or when applying recirculation rates of 2.6 min(-1), the entrapped enzyme was around two-fold more stable at 80 degrees C than free CelB. The significance of the stabilisation was attenuated by the decrease in CelB initial activity which was due to cross-linking and glutardialdehyde concentration-dependent. Entrapment facilitated downstream processing of CelB and biocatalyst recovery in repeated batchwise conversions of lactose at elevated temperatures.
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Affiliation(s)
- Thomas Kamrat
- Research Centre Applied Biocatalysis, Petersgasse 14, c/o Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12, A-8010 Graz, Austria
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Endoh T, Kanai T, Sato YT, Liu DV, Yoshikawa K, Atomi H, Imanaka T. Cell-free protein synthesis at high temperatures using the lysate of a hyperthermophile. J Biotechnol 2006; 126:186-95. [PMID: 16730835 DOI: 10.1016/j.jbiotec.2006.04.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Revised: 03/28/2006] [Accepted: 04/07/2006] [Indexed: 11/29/2022]
Abstract
Systems for cell-free protein synthesis available today are usually based on the lysates of either Escherichia coli, wheat germ or rabbit reticulocyte, and protein synthesis reactions using these extracts are performed at moderate temperatures (20-40 degrees C). We report here the development of a novel system for cell-free protein synthesis that can be operated at high temperatures using a lysate of the hyperthermophilic archaeon, Thermococcus kodakaraensis. With the system, cell-free protein synthesis of ChiADelta4, a derivative of T. kodakaraensis chitinase (ChiA), was observed within a temperature range of 40-80 degrees C, with an optimum at 65 degrees C. Corresponding chitinase activity was also detected in the reaction mixtures after cell-free protein synthesis, indicating that the synthesized ChiADelta4 folded in a proper tertiary structure. The maximum concentration of active ChiADelta4 synthesized was determined to be approximately 1.3 microg/mL. A time course experiment indicated that the amount of synthesized ChiADelta4 saturated within 30 min at 65 degrees C, and energy depletion was suggested to be the main cause of this saturation. We further developed a system for transcription and translation-coupled protein synthesis at high temperatures using a combination of T. kodakaraensis lysate and thermostable T7 RNA polymerase.
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Affiliation(s)
- Takashi Endoh
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Kyoto 615-8510, Japan
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31
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Machielsen R, van der Oost J. Production and characterization of a thermostable L-threonine dehydrogenase from the hyperthermophilic archaeon Pyrococcus furiosus. FEBS J 2006; 273:2722-9. [PMID: 16817900 DOI: 10.1111/j.1742-4658.2006.05290.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The gene encoding a threonine dehydrogenase (TDH) has been identified in the hyperthermophilic archaeon Pyrococcus furiosus. The Pf-TDH protein has been functionally produced in Escherichia coli and purified to homogeneity. The enzyme has a tetrameric conformation with a molecular mass of approximately 155 kDa. The catalytic activity of the enzyme increases up to 100 degrees C, and a half-life of 11 min at this temperature indicates its thermostability. The enzyme is specific for NAD(H), and maximal specific activities were detected with L-threonine (10.3 U x mg(-1)) and acetoin (3.9 U x mg(-1)) in the oxidative and reductive reactions, respectively. Pf-TDH also utilizes L-serine and D-threonine as substrate, but could not oxidize other L-amino acids. The enzyme requires bivalent cations such as Zn2+ and Co2+ for activity and contains at least one zinc atom per subunit. Km values for L-threonine and NAD+ at 70 degrees C were 1.5 mm and 0.055 mm, respectively.
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32
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Machielsen R, Uria AR, Kengen SWM, van der Oost J. Production and characterization of a thermostable alcohol dehydrogenase that belongs to the aldo-keto reductase superfamily. Appl Environ Microbiol 2006; 72:233-8. [PMID: 16391048 PMCID: PMC1352300 DOI: 10.1128/aem.72.1.233-238.2006] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The gene encoding a novel alcohol dehydrogenase that belongs to the aldo-keto reductase superfamily has been identified in the hyperthermophilic archaeon Pyrococcus furiosus. The gene, referred to as adhD, was functionally expressed in Escherichia coli and subsequently purified to homogeneity. The enzyme has a monomeric conformation with a molecular mass of 32 kDa. The catalytic activity of the enzyme increases up to 100 degrees C, and a half-life value of 130 min at this temperature indicates its high thermostability. AdhD exhibits a broad substrate specificity with, in general, a preference for the reduction of ketones (pH optimum, 6.1) and the oxidation of secondary alcohols (pH optimum, 8.8). Maximal specific activities were detected with 2,3-butanediol (108.3 U/mg) and diacetyl-acetoin (22.5 U/mg) in the oxidative and reductive reactions, respectively. Gas chromatrography analysis indicated that AdhD produced mainly (S)-2-pentanol (enantiomeric excess, 89%) when 2-pentanone was used as substrate. The physiological role of AdhD is discussed.
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Affiliation(s)
- Ronnie Machielsen
- Laboratory of Microbiology, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands.
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33
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Kanai T, Imanaka H, Nakajima A, Uwamori K, Omori Y, Fukui T, Atomi H, Imanaka T. Continuous hydrogen production by the hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1. J Biotechnol 2005; 116:271-82. [PMID: 15707688 DOI: 10.1016/j.jbiotec.2004.11.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2004] [Revised: 11/12/2004] [Accepted: 11/18/2004] [Indexed: 11/18/2022]
Abstract
The hydrogen (H2) production potential of the hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1 was evaluated at 85 degrees C. In batch cultivation using a complex medium supplemented with elemental sulfur (S0), evolution of H2S and CO2 was observed in the gas phase. When S0 was omitted and pyruvate or starch was added in the medium, the cells produced H2 at high levels instead of H2S. As the level of H2 appeared to correlate with the specific growth rate, analysis in continuous cultures was performed to develop a continuous H2 production system. In a steady-state condition at a dilution rate of 0.2 h-1, a continuous H2 production rate (per gram dry weight, gdw) of 24.9 and 14.0 mmol gdw-1 h-1 was observed in media supplemented with pyruvate and starch, respectively. In both cultivations, a high accumulation of acetate and alanine was found as metabolites. When the dilution rates were elevated in the medium with pyruvate, steady-state growth was observed up to 0.8 h-1, and a maximum H2 production rate of 59.6 mmol gdw-1 h-1 was obtained. Based on the experimental results along with data of the entire genome sequence, the metabolic pathway of the strain relating to starch and pyruvate degradation is discussed.
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Affiliation(s)
- Tamotsu Kanai
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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Significance of polysaccharides in microbial physiology and the ecology of hydrothermal vent environments. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/144gm14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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35
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Ito S, Fushinobu S, Jeong JJ, Yoshioka I, Koga S, Shoun H, Wakagi T. Crystal structure of an ADP-dependent glucokinase from Pyrococcus furiosus: implications for a sugar-induced conformational change in ADP-dependent kinase. J Mol Biol 2003; 331:871-83. [PMID: 12909015 DOI: 10.1016/s0022-2836(03)00792-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
ADP-dependent kinases are used in the modified Embden-Meyerhoff pathway of certain archaea. Our previous study has revealed a mechanism for ADP-dependent phosphoryl transfer by Thermococcus litoralis glucokinase (tlGK), and its evolutionary relationship with ATP-dependent ribokinases and adenosine kinases (PFKB carbohydrate kinase family members). Here, we report the crystal structure of glucokinase from Pyrococcus furiosus (pfGK) in a closed conformation complexed with glucose and AMP at 1.9A resolution. In comparison with the tlGK structure, the pfGK structure shows significant conformational changes in the small domain and a region around the hinge, suggesting glucose-induced domain closing. A part of the large domain next to the hinge is also shifted accompanied with domain closing. In the pfGK structure, glucose binds in a groove between the large and small domains, and the electron density of O1 atoms for both the alpha and beta-anomer configurations was observed. The structural details of the sugar-binding site of ADP-dependent glucokinase were firstly clarified and then site-directed mutagenesis analysis clarified the catalytic residues for ADP-dependent kinase, such as Arg205 and Asp451 of tlGK. Homology search and multiple alignment of amino acid sequences using the information obtained from the structures reveals that eucaryotic hypothetical proteins homologous to ADP-dependent kinases retain the residues for the recognition of a glucose substrate.
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Affiliation(s)
- Sohei Ito
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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36
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van Niel EWJ, Claassen PAM, Stams AJM. Substrate and product inhibition of hydrogen production by the extreme thermophile, Caldicellulosiruptor saccharolyticus. Biotechnol Bioeng 2003; 81:255-62. [PMID: 12474247 DOI: 10.1002/bit.10463] [Citation(s) in RCA: 242] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Substrate and product inhibition of hydrogen production during sucrose fermentation by the extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus was studied. The inhibition kinetics were analyzed with a noncompetitive, nonlinear inhibition model. Hydrogen was the most severe inhibitor when allowed to accumulate in the culture. Concentrations of 5-10 mM H(2) in the gas phase (identical with partial hydrogen pressure (pH(2)) of (1-2) x 10(4) Pa) initiated a metabolic shift to lactate formation. The extent of inhibition by hydrogen was dependent on the density of the culture. The highest tolerance for hydrogen was found at low volumetric hydrogen production rates, as occurred in cultures with low cell densities. Under those conditions the critical hydrogen concentration in the gas phase was 27.7 mM H(2) (identical with pH(2) of 5.6 x 10(4) Pa); above this value hydrogen production ceased completely. With an efficient removal of hydrogen sucrose fermentation was mainly inhibited by sodium acetate. The critical concentrations of sucrose and acetate, at which growth and hydrogen production was completely inhibited (at neutral pH and 70 degrees C), were 292 and 365 mM, respectively. Inorganic salts, such as sodium chloride, mimicked the effect of sodium acetate, implying that ionic strength was responsible for inhibition. Undissociated acetate did not contribute to inhibition of cultures at neutral or slightly acidic pH. Exposure of exponentially growing cultures to concentrations of sodium acetate or sodium chloride higher than ca. 175 mM caused cell lysis, probably due to activation of autolysins.
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Affiliation(s)
- Ed W J van Niel
- Laboratory for Microbiology, Wageningen University and Research Center, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands.
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37
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Martin W, Russell MJ. On the origins of cells: a hypothesis for the evolutionary transitions from abiotic geochemistry to chemoautotrophic prokaryotes, and from prokaryotes to nucleated cells. Philos Trans R Soc Lond B Biol Sci 2003; 358:59-83; discussion 83-5. [PMID: 12594918 PMCID: PMC1693102 DOI: 10.1098/rstb.2002.1183] [Citation(s) in RCA: 401] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
All life is organized as cells. Physical compartmentation from the environment and self-organization of self-contained redox reactions are the most conserved attributes of living things, hence inorganic matter with such attributes would be life's most likely forebear. We propose that life evolved in structured iron monosulphide precipitates in a seepage site hydrothermal mound at a redox, pH and temperature gradient between sulphide-rich hydrothermal fluid and iron(II)-containing waters of the Hadean ocean floor. The naturally arising, three-dimensional compartmentation observed within fossilized seepage-site metal sulphide precipitates indicates that these inorganic compartments were the precursors of cell walls and membranes found in free-living prokaryotes. The known capability of FeS and NiS to catalyse the synthesis of the acetyl-methylsulphide from carbon monoxide and methylsulphide, constituents of hydrothermal fluid, indicates that pre-biotic syntheses occurred at the inner surfaces of these metal-sulphide-walled compartments, which furthermore restrained reacted products from diffusion into the ocean, providing sufficient concentrations of reactants to forge the transition from geochemistry to biochemistry. The chemistry of what is known as the RNA-world could have taken place within these naturally forming, catalyticwalled compartments to give rise to replicating systems. Sufficient concentrations of precursors to support replication would have been synthesized in situ geochemically and biogeochemically, with FeS (and NiS) centres playing the central catalytic role. The universal ancestor we infer was not a free-living cell, but rather was confined to the naturally chemiosmotic, FeS compartments within which the synthesis of its constituents occurred. The first free-living cells are suggested to have been eubacterial and archaebacterial chemoautotrophs that emerged more than 3.8 Gyr ago from their inorganic confines. We propose that the emergence of these prokaryotic lineages from inorganic confines occurred independently, facilitated by the independent origins of membrane-lipid biosynthesis: isoprenoid ether membranes in the archaebacterial and fatty acid ester membranes in the eubacterial lineage. The eukaryotes, all of which are ancestrally heterotrophs and possess eubacterial lipids, are suggested to have arisen ca. 2 Gyr ago through symbiosis involving an autotrophic archaebacterial host and a heterotrophic eubacterial symbiont, the common ancestor of mitochondria and hydrogenosomes. The attributes shared by all prokaryotes are viewed as inheritances from their confined universal ancestor. The attributes that distinguish eubacteria and archaebacteria, yet are uniform within the groups, are viewed as relics of their phase of differentiation after divergence from the non-free-living universal ancestor and before the origin of the free-living chemoautotrophic lifestyle. The attributes shared by eukaryotes with eubacteria and archaebacteria, respectively, are viewed as inheritances via symbiosis. The attributes unique to eukaryotes are viewed as inventions specific to their lineage. The origin of the eukaryotic endomembrane system and nuclear membrane are suggested to be the fortuitous result of the expression of genes for eubacterial membrane lipid synthesis by an archaebacterial genetic apparatus in a compartment that was not fully prepared to accommodate such compounds, resulting in vesicles of eubacterial lipids that accumulated in the cytosol around their site of synthesis. Under these premises, the most ancient divide in the living world is that between eubacteria and archaebacteria, yet the steepest evolutionary grade is that between prokaryotes and eukaryotes.
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Affiliation(s)
- William Martin
- Institut für Botanik III, Heinrich-Heine Universitaet Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
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Arutyunov DY, Muronetz VI. The activation of glycolysis performed by the non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase in the model system. Biochem Biophys Res Commun 2003; 300:149-54. [PMID: 12480534 DOI: 10.1016/s0006-291x(02)02802-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Influence of non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase (GAPN) on glycolysis was investigated. The addition of GAPN-which oxidizes glyceraldehyde-3-phosphate directly to the 3-phosphoglyceric acid-led to the strong increase in the rate of lactate accumulation in the rat muscle extract with low ADP content. The lactate accumulation was also observed in the presence of GAPN in rat muscle extract, which contained only ATP and no ADP. This can be the evidence of the "futile cycle" stimulated by GAPN. Here ADP can be regenerated from ATP by the phosphoglycerate kinase reaction. The high resistance of GAPN from Streptococcus mutans towards inactivation by natural oxidant-H(2)O(2) was showed. This feature distinguishes GAPN from phosphorylating glyceraldehyde-3-phosphate dehydrogenase, which is very sensitive to modification by hydrogen peroxide. A possible role of the oxidants and non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase in the regulation of glycolysis is discussed.
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Affiliation(s)
- D Y Arutyunov
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia
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Abstract
Pyrococcus furiosus ferredoxin is subject to a monomer/dimer equilibrium as a function of ionic strength. At physiological ionic strength, approximately 0.35 M NaCl, the protein is very predominantly homodimer. The monomeric form exhibits impaired electron transfer on glassy carbon; it also has a decreased S=3/2 over S=1/2 ratio as shown by electron paramagnetic resonance spectroscopy. Even following sterilization at 121 degrees C the dimer is stable in denaturing gel electrophoresis.
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Affiliation(s)
- M N Hasan
- Kluyver Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
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40
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Hansen T, Reichstein B, Schmid R, Schönheit P. The first archaeal ATP-dependent glucokinase, from the hyperthermophilic crenarchaeon Aeropyrum pernix, represents a monomeric, extremely thermophilic ROK glucokinase with broad hexose specificity. J Bacteriol 2002; 184:5955-65. [PMID: 12374829 PMCID: PMC135380 DOI: 10.1128/jb.184.21.5955-5965.2002] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2002] [Accepted: 07/19/2002] [Indexed: 11/20/2022] Open
Abstract
An ATP-dependent glucokinase of the hyperthermophilic aerobic crenarchaeon Aeropyrum pernix was purified 230-fold to homogeneity. The enzyme is a monomeric protein with an apparent molecular mass of about 36 kDa. The apparent K(m) values for ATP and glucose (at 90 degrees C and pH 6.2) were 0.42 and 0.044 mM, respectively; the apparent V(max) was about 35 U/mg. The enzyme was specific for ATP as a phosphoryl donor, but showed a broad spectrum for phosphoryl acceptors: in addition to glucose, which showed the highest catalytic efficiency (k(cat)/K(m)), the enzyme also phosphorylates glucosamin, fructose, mannose, and 2-deoxyglucose. Divalent cations were required for maximal activity: Mg(2+), which was most effective, could partially be replaced with Co(2+), Mn(2+), and Ni(2+). The enzyme had a temperature optimum of at least 100 degrees C and showed significant thermostability up to 100 degrees C. The coding function of open reading frame (ORF) APE2091 (Y. Kawarabayasi, Y. Hino, H. Horikawa, S. Yamazaki, Y. Haikawa, K. Jin-no, M. Takahashi, M. Sekine, S. Baba, A. Ankai, H. Kosugi, A. Hosoyama, S. Fukui, Y. Nagai, K. Nishijima, H. Nakazawa, M. Takamiya, S. Masuda, T. Funahashi, T. Tanaka, Y. Kudoh, J. Yamazaki, N. Kushida, A. Oguchi, and H. Kikuchi, DNA Res. 6:83-101, 145-152, 1999), previously annotated as gene glk, coding for ATP-glucokinase of A. pernix, was proved by functional expression in Escherichia coli. The purified recombinant ATP-dependent glucokinase showed a 5-kDa higher molecular mass on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but almost identical kinetic and thermostability properties in comparison to the native enzyme purified from A. pernix. N-terminal amino acid sequence of the native enzyme revealed that the translation start codon is a GTG 171 bp downstream of the annotated start codon of ORF APE2091. The amino acid sequence deduced from the truncated ORF APE2091 revealed sequence similarity to members of the ROK family, which comprise bacterial sugar kinases and transcriptional repressors. This is the first report of the characterization of an ATP-dependent glucokinase from the domain of Archaea, which differs from its bacterial counterparts by its monomeric structure and its broad specificity for hexoses.
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Affiliation(s)
- Thomas Hansen
- Institut für Allgemeine Mikrobiologie, Christian-Albrechts-Universität Kiel, D-24118 Kiel, Am Botanischen Garten 1-9, Germany
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Chhabra SR, Shockley KR, Ward DE, Kelly RM. Regulation of endo-acting glycosyl hydrolases in the hyperthermophilic bacterium Thermotoga maritima grown on glucan- and mannan-based polysaccharides. Appl Environ Microbiol 2002; 68:545-54. [PMID: 11823189 PMCID: PMC126696 DOI: 10.1128/aem.68.2.545-554.2002] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2001] [Accepted: 11/12/2001] [Indexed: 11/20/2022] Open
Abstract
The genome sequence of the hyperthermophilic bacterium Thermotoga maritima encodes a number of glycosyl hydrolases. Many of these enzymes have been shown in vitro to degrade specific glycosides that presumably serve as carbon and energy sources for the organism. However, because of the broad substrate specificity of many glycosyl hydrolases, it is difficult to determine the physiological substrate preferences for specific enzymes from biochemical information. In this study, T. maritima was grown on a range of polysaccharides, including barley beta-glucan, carboxymethyl cellulose, carob galactomannan, konjac glucomannan, and potato starch. In all cases, significant growth was observed, and cell densities reached 10(9) cells/ml. Northern blot analyses revealed different substrate-dependent expression patterns for genes encoding the various endo-acting beta-glycosidases; these patterns ranged from strong expression to no expression under the conditions tested. For example, cel74 (TM0305), a gene encoding a putative beta-specific endoglucananse, was strongly expressed on all substrates tested, including starch, while no evidence of expression was observed on any substrate for lam16 (TM0024), xyl10A (TM0061), xyl10B (TM0070), and cel12A (TM1524), which are genes that encode a laminarinase, two xylanases, and an endoglucanase, respectively. The cel12B (TM1525) gene, which encodes an endoglucanase, was expressed only on carboxymethyl cellulose. An extracellular mannanase encoded by man5 (TM1227) was expressed on carob galactomannan and konjac glucomannan and to a lesser extent on carboxymethyl cellulose. An unexpected result was the finding that the cel5A (TM1751) and cel5B (TM1752) genes, which encode putative intracellular beta-specific endoglucanases, were induced only when T. maritima was grown on konjac glucomannan. To investigate the biochemical basis of this finding, the recombinant forms of Man5 (M(r), 76,900) and Cel5A (M(r), 37,400) were expressed in Escherichia coli and characterized. Man5, a T. maritima extracellular enzyme, had a melting temperature of 99 degrees C and an optimun temperature of 90 degrees C, compared to 90 and 80 degrees C, respectively, for the intracellular enzyme Cel5A. While Man5 hydrolyzed both galactomannan and glucomannan, no activity was detected on glucans or xylans. Cel5A, however, not only hydrolyzed barley beta-glucan, carboxymethyl cellulose, xyloglucan, and lichenin but also had activity comparable to that of Man5 on galactomannan and higher activity than Man5 on glucomannan. The biochemical characteristics of Cel5A, the fact that Cel5A was induced only when T. maritima was grown on glucomannan, and the intracellular localization of Cel5A suggest that the physiological role of this enzyme includes hydrolysis of glucomannan oligosaccharides that are transported following initial hydrolysis by extracellular glycosidases, such as Man5.
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Affiliation(s)
- Swapnil R Chhabra
- Department of Chemical Engineering, North Carolina State University, Stinson Drive, Raleigh, NC 27695-7905, USA
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42
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Kengen SW, Tuininga JE, Verhees CH, van der Oost J, Stams AJ, de Vos WM. ADP-dependent glucokinase and phosphofructokinase from Pyrococcus furiosus. Methods Enzymol 2001; 331:41-53. [PMID: 11265478 DOI: 10.1016/s0076-6879(01)31045-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- S W Kengen
- Laboratory of Microbiology, Wageningen University, 6703 CT Wageningen, The Netherlands
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43
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Hansen T, Oehlmann M, Schönheit P. Novel type of glucose-6-phosphate isomerase in the hyperthermophilic archaeon Pyrococcus furiosus. J Bacteriol 2001; 183:3428-35. [PMID: 11344151 PMCID: PMC99641 DOI: 10.1128/jb.183.11.3428-3435.2001] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Glucose-6-phosphate isomerase (phosphoglucose isomerase [PGI]) (EC 5.3.1.9) from the hyperthermophilic archaeon Pyrococcus furiosus was purified 500-fold to homogeneity. The enzyme had an apparent molecular mass of 43 kDa and was composed of a single type of subunit of 23 kDa indicating a homodimeric (alpha(2)) structure. Kinetic constants of the enzyme were determined at the optimal pH 7 and at 80 degrees C. Rate dependence on both substrates followed Michaelis-Menten kinetics. The apparent K(m) values for glucose-6-phosphate and fructose-6-phosphate were 8.7 and 1.0 mM, respectively, and the corresponding apparent V(max) values were 800 and 130 U/mg. The enzyme had a temperature optimum of 96 degrees C and showed a significant thermostability up to 100 degrees C, which is in accordance with its physiological function under hyperthermophilic conditions. Based on the N-terminal amino acid sequence of the subunit, a single open reading frame (ORF; Pf_209264) was identified in the genome of P. furiosus. The ORF was characterized by functional overexpression in Escherichia coli as a gene, pgi, encoding glucose-6-phosphate isomerase. The recombinant PGI was purified and showed molecular and kinetic properties almost identical to those of the native PGI purified from P. furiosus. The deduced amino acid sequence of P. furiosus PGI did not reveal significant similarity to the conserved PGI superfamily of eubacteria and eucarya. This is the first description of an archaeal PGI, which represents a novel type of PGI.
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Affiliation(s)
- T Hansen
- Institut für Allgemeine Mikrobiologie, Christian-Albrechts-Universität Kiel, Am Botanischen Garten 1-9, D-24118 Kiel, Germany
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Henrissat B, Coutinho PM. Classification of glycoside hydrolases and glycosyltransferases from hyperthermophiles. Methods Enzymol 2001; 330:183-201. [PMID: 11210498 DOI: 10.1016/s0076-6879(01)30375-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- B Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS-IFR1, Marseille, France
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Ito S, Fushinobu S, Yoshioka I, Koga S, Matsuzawa H, Wakagi T. Structural basis for the ADP-specificity of a novel glucokinase from a hyperthermophilic archaeon. Structure 2001; 9:205-14. [PMID: 11286887 DOI: 10.1016/s0969-2126(01)00577-9] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND ATP is the most common phosphoryl group donor for kinases. However, certain hyperthermophilic archaea such as Thermococcus litoralis and Pyrococcus furiosus utilize unusual ADP-dependent glucokinases and phosphofructokinases in their glycolytic pathways. These ADP-dependent kinases are homologous to each other but show no sequence similarity to any of the hitherto known ATP-dependent enzymes. RESULTS We solved the crystal structure at 2.3 A resolution of an ADP-dependent glucokinase from T. litoralis (tlGK) complexed with ADP. The overall structure can be divided into large and small alpha/beta domains, and the ADP molecule is buried in a shallow pocket in the large domain. Unexpectedly, the structure was similar to those of two ATP-dependent kinases, ribokinase and adenosine kinase. Comparison based on three-dimensional structure revealed that several motifs important both in structure and function are conserved, and the recognition of the alpha- and beta-phosphate of the ADP in the tlGK was almost identical with the recognition of the beta- and gamma-phosphate of ATP in these ATP-dependent kinases. CONCLUSIONS Noticeable points of our study are the first structure of ADP-dependent kinase, the structural similarity to members of the ATP-dependent ribokinase family, its rare nucleotide specificity caused by a shift in nucleotide binding position by one phosphate unit, and identification of the residues that discriminate ADP- and ATP-dependence. The strict conservation of the binding site for the terminal and adjacent phosphate moieties suggests a common ancestral origin of both the ATP- and ADP-dependent kinases.
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Affiliation(s)
- S Ito
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-Ku, Tokyo 113-8657, Japan
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Hutchins AM, Holden JF, Adams MW. Phosphoenolpyruvate synthetase from the hyperthermophilic archaeon Pyrococcus furiosus. J Bacteriol 2001; 183:709-15. [PMID: 11133966 PMCID: PMC94928 DOI: 10.1128/jb.183.2.709-715.2001] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Phosphoenolpyruvate synthetase (PpsA) was purified from the hyperthermophilic archaeon Pyrococcus furiosus. This enzyme catalyzes the conversion of pyruvate and ATP to phosphoenolpyruvate (PEP), AMP, and phosphate and is thought to function in gluconeogenesis. PpsA has a subunit molecular mass of 92 kDa and contains one calcium and one phosphorus atom per subunit. The active form has a molecular mass of 690+/-20 kDa and is assumed to be octomeric, while approximately 30% of the protein is purified as a large ( approximately 1.6 MDa) complex that is not active. The apparent K(m) values and catalytic efficiencies for the substrates pyruvate and ATP (at 80 degrees C, pH 8.4) were 0.11 mM and 1.43 x 10(4) mM(-1). s(-1) and 0.39 mM and 3.40 x 10(3) mM(-1) x s(-1), respectively. Maximal activity was measured at pH 9.0 (at 80 degrees C) and at 90 degrees C (at pH 8.4). The enzyme also catalyzed the reverse reaction, but the catalytic efficiency with PEP was very low [k(cat)/K(m) = 32 (mM. s(-1)]. In contrast to several other nucleotide-dependent enzymes from P. furiosus, PpsA has an absolute specificity for ATP as the phosphate-donating substrate. This is the first PpsA from a nonmethanogenic archaeon to be biochemically characterized. Its kinetic properties are consistent with a role in gluconeogenesis, although its relatively high cellular concentration ( approximately 5% of the cytoplasmic protein) suggests an additional function possibly related to energy spilling. It is not known whether interconversion between the smaller, active and larger, inactive forms of the enzyme has any functional role.
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Affiliation(s)
- A M Hutchins
- Department of Biochemistry and Molecular Biology and Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602, USA
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Silva PJ, van den Ban EC, Wassink H, Haaker H, de Castro B, Robb FT, Hagen WR. Enzymes of hydrogen metabolism in Pyrococcus furiosus. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:6541-51. [PMID: 11054105 DOI: 10.1046/j.1432-1327.2000.01745.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The genome of Pyrococcus furiosus contains the putative mbhABCDEFGHIJKLMN operon for a 14-subunit transmembrane complex associated with a Ni-Fe hydrogenase. Ten ORFs (mbhA-I and mbhM) encode hydrophobic, membrane-spanning subunits. Four ORFs (mbhJKL and mbhN) encode putative soluble proteins. Two of these correspond to the canonical small and large subunit of Ni-Fe hydrogenase, however, the small subunit can coordinate only a single iron-sulfur cluster, corresponding to the proximal [4Fe-4S] cubane. The structural genes for the small and the large subunits, mbhJ and mbhL, are separated in the genome by a third ORF, mbhK, encoding a protein of unknown function without Fe/S binding. The fourth ORF, mbhN, encodes a 2[4Fe-4S] protein. With P. furiosus soluble [4Fe-4S] ferredoxin as the electron donor the membranes produce H2, and this activity is retained in an extracted core complex of the mbh operon when solubilized and partially purified under mild conditions. The properties of this membrane-bound hydrogenase are unique. It is rather resistant to inhibition by carbon monoxide. It also exhibits an extremely high ratio of H2 evolution to H2 uptake activity compared with other hydrogenases. The activity is sensitive to inhibition by dicyclohexylcarbodiimide, an inhibitor of NADH dehydrogenase (complex I). EPR of the reduced core complex is characteristic for interacting iron-sulfur clusters with Em approximately -0.33 V. The genome contains a second putative operon, mbxABCDFGHH'MJKLN, for a multisubunit transmembrane complex with strong homology to the mbh operon, however, with a highly unusual putative binding motif for the Ni-Fe-cluster in the large hydrogenase subunit. Kinetic studies of membrane-bound hydrogenase, soluble hydrogenase and sulfide dehydrogenase activities allow the formulation of a comprehensive working hypothesis of H2 metabolism in P. furiosus in terms of three pools of reducing equivalents (ferredoxin, NADPH, H2) connected by devices for transduction, transfer, recovery and safety-valving of energy.
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Affiliation(s)
- P J Silva
- Kluyver Department of Biotechnology, Delft University of Technology, The Netherlands
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Rinker KD, Kelly RM. Effect of carbon and nitrogen sources on growth dynamics and exopolysaccharide production for the hyperthermophilic archaeon Thermococcus litoralis and bacterium Thermotoga maritima. Biotechnol Bioeng 2000; 69:537-47. [PMID: 10898863 DOI: 10.1002/1097-0290(20000905)69:5<537::aid-bit8>3.0.co;2-7] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Batch and continuous cultures were used to compare specific physiological features of the hyperthermophilic archaeon, Thermococcus litoralis (T(opt) of 85 degrees to 88 degrees C), to another fermentative hyperthermophile that reduces S degrees facultatively, that is, the bacterium Thermotoga maritima (T(opt) of 80 degrees to 85 degrees C). Under nutritionally optimal conditions, these two hyperthermophiles had similar growth yields on maltose and similar cell formula weights based on elemental analysis: CH(1.7)O(0. 7)N(0.2)S(0.006) for T. litoralis and CH(1.6)O(0.6)N(0.2)S(0.005) for T. maritima. However, they differed with respect to nitrogen source, fermentation product patterns, and propensity to form exopolysaccharides (EPS). T. litoralis could be cultured in the absence or presence of maltose on an amino acid-containing defined medium in which amino acids served as the sole nitrogen source. T. maritima, on the other hand, did not utilize amino acids as carbon, energy, or nitrogen sources, and could be grown in a similar defined medium only when supplemented with maltose and ammonium chloride. Not only was T. litoralis unable to utilize NH(4)Cl as a nitrogen source, its growth was inhibited at certain levels. At 1 g/L ( approximately 20 mM) NH(4)Cl, the maximum growth yield (Y(x/s(max))) for T. litoralis was reduced to 13 g cells dry weight (CDW)/mol glucose from 40 g CDW/mol glucose in media lacking NH(4)Cl. Alanine production increased with increasing NH(4)Cl concentrations and was most pronounced if growth on NH(4)Cl was carried out in an 80% H(2) atmosphere. In T. maritima cultures, which would not grow in an 80% H(2) atmosphere, alanine and EPS were produced at much lower levels, which did not change with NH(4)Cl concentration. EPS production rose sharply at high dilution rates for both organisms, such that maltose utilization plots were biphasic. Wall growth effects were also noted, because cultures failed to wash out at dilution rates significantly above maximum growth rates determined from batch growth experiments. This study illustrates the importance of effective cultivation methods for addressing physiological issues related to the growth of hyperthermophilic heterotrophs.
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Affiliation(s)
- K D Rinker
- Department of Chemical Engineering, North Carolina State University, PO Box 7905, Raleigh, North Carolina 27695-7905, USA
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Sapra R, Verhagen MF, Adams MW. Purification and characterization of a membrane-bound hydrogenase from the hyperthermophilic archaeon Pyrococcus furiosus. J Bacteriol 2000; 182:3423-8. [PMID: 10852873 PMCID: PMC101913 DOI: 10.1128/jb.182.12.3423-3428.2000] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Highly washed membrane preparations from cells of the hyperthermophilic archaeon Pyrococcus furiosus contain high hydrogenase activity (9.4 micromol of H(2) evolved/mg at 80 degrees C) using reduced methyl viologen as the electron donor. The enzyme was solubilized with n-dodecyl-beta-D-maltoside and purified by multistep chromatography in the presence of Triton X-100. The purified preparation contained two major proteins (alpha and beta) in an approximate 1:1 ratio with a minimum molecular mass near 65 kDa and contained approximately 1 Ni and 4 Fe atoms/mol. The reduced enzyme gave rise to an electron paramagnetic resonance signal typical of the so-called Ni-C center of mesophilic NiFe-hydrogenases. Neither highly washed membranes nor the purified enzyme used NAD(P)(H) or P. furiosus ferredoxin as an electron carrier, nor did either catalyze the reduction of elemental sulfur with H(2) as the electron donor. Using N-terminal amino acid sequence information, the genes proposed to encode the alpha and beta subunits were located in the genome database within a putative 14-gene operon (termed mbh). The deduced sequences of the two subunits (Mbh 11 and 12) were distinctly different from those of the four subunits that comprise each of the two cytoplasmic NiFe-hydrogenases of P. furiosus and show that the alpha subunit contains the NiFe-catalytic site. Six of the open reading frames (ORFs) in the operon, including those encoding the alpha and beta subunits, show high sequence similarity (>30% identity) with proteins associated with the membrane-bound NiFe-hydrogenase complexes from Methanosarcina barkeri, Escherichia coli, and Rhodospirillum rubrum. The remaining eight ORFs encode small (<19-kDa) hypothetical proteins. These data suggest that P. furiosus, which was thought to be solely a fermentative organism, may contain a previously unrecognized respiratory system in which H(2) metabolism is coupled to energy conservation.
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Affiliation(s)
- R Sapra
- Department of Biochemistry and Molecular Biology and Center for Metalloenzyme Studies, University of Georgia, Athens 30602, USA
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50
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Ward DE, Kengen SW, van Der Oost J, de Vos WM. Purification and characterization of the alanine aminotransferase from the hyperthermophilic Archaeon pyrococcus furiosus and its role in alanine production. J Bacteriol 2000; 182:2559-66. [PMID: 10762259 PMCID: PMC111321 DOI: 10.1128/jb.182.9.2559-2566.2000] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Alanine aminotransferase (AlaAT) was purified from cell extracts of the hyperthermophilic archaeon Pyrococcus furiosus by multistep chromatography. The enzyme has an apparent molecular mass of 93.5 kDa, as estimated by gel filtration, and consists of two identical subunits of 46 kDa, as deduced by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the gene sequence. The AlaAT displayed a broader substrate specificity than AlaATs from eukaryal sources and exhibited significant activity with alanine, glutamate, and aspartate with either 2-oxoglutarate or pyruvate as the amino acceptor. Optimal activity was found in the pH range of 6. 5 to 7.8 and at a temperature of over 95 degrees C. The N-terminal amino acid sequence of the purified AlaAT was determined and enabled the identification of the gene encoding AlaAT (aat) in the P. furiosus genome database. The gene was expressed in Escherichia coli, and the recombinant enzyme was purified. The pH and temperature dependence, molecular mass, and kinetic parameters of the recombinant were indistinguishable from those of the native enzyme from P. furiosus. The k(cat)/K(m) values for alanine and pyruvate formation were 41 and 33 s(-1) mM(-1), respectively, suggesting that the enzyme is not biased toward either the formation of pyruvate, or alanine. Northern analysis identified a single 1.2-kb transcript for the aat gene. In addition, both the aat and gdh (encoding the glutamate dehydrogenase) transcripts appear to be coregulated at the transcriptional level, because the expression of both genes was induced when the cells were grown on pyruvate. The coordinated control found for the aat and gdh genes is in good agreement with these enzymes acting in a concerted manner to form an electron sink in P. furiosus.
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Affiliation(s)
- D E Ward
- Laboratory of Microbiology, Wageningen Agricultural University, NL-6703 CT Wageningen, The Netherlands.
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