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Cifuente JO, Colleoni C, Kalscheuer R, Guerin ME. Architecture, Function, Regulation, and Evolution of α-Glucans Metabolic Enzymes in Prokaryotes. Chem Rev 2024; 124:4863-4934. [PMID: 38606812 PMCID: PMC11046441 DOI: 10.1021/acs.chemrev.3c00811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Bacteria have acquired sophisticated mechanisms for assembling and disassembling polysaccharides of different chemistry. α-d-Glucose homopolysaccharides, so-called α-glucans, are the most widespread polymers in nature being key components of microorganisms. Glycogen functions as an intracellular energy storage while some bacteria also produce extracellular assorted α-glucans. The classical bacterial glycogen metabolic pathway comprises the action of ADP-glucose pyrophosphorylase and glycogen synthase, whereas extracellular α-glucans are mostly related to peripheral enzymes dependent on sucrose. An alternative pathway of glycogen biosynthesis, operating via a maltose 1-phosphate polymerizing enzyme, displays an essential wiring with the trehalose metabolism to interconvert disaccharides into polysaccharides. Furthermore, some bacteria show a connection of intracellular glycogen metabolism with the genesis of extracellular capsular α-glucans, revealing a relationship between the storage and structural function of these compounds. Altogether, the current picture shows that bacteria have evolved an intricate α-glucan metabolism that ultimately relies on the evolution of a specific enzymatic machinery. The structural landscape of these enzymes exposes a limited number of core catalytic folds handling many different chemical reactions. In this Review, we present a rationale to explain how the chemical diversity of α-glucans emerged from these systems, highlighting the underlying structural evolution of the enzymes driving α-glucan bacterial metabolism.
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Affiliation(s)
- Javier O. Cifuente
- Instituto
Biofisika (UPV/EHU, CSIC), University of
the Basque Country, E-48940 Leioa, Spain
| | - Christophe Colleoni
- University
of Lille, CNRS, UMR8576-UGSF -Unité de Glycobiologie Structurale
et Fonctionnelle, F-59000 Lille, France
| | - Rainer Kalscheuer
- Institute
of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, 40225 Dusseldorf, Germany
| | - Marcelo E. Guerin
- Structural
Glycobiology Laboratory, Department of Structural and Molecular Biology, Molecular Biology Institute of Barcelona (IBMB), Spanish
National Research Council (CSIC), Barcelona Science Park, c/Baldiri Reixac 4-8, Tower R, 08028 Barcelona, Catalonia, Spain
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Leung PM, Bay SK, Meier DV, Chiri E, Cowan DA, Gillor O, Woebken D, Greening C. Energetic Basis of Microbial Growth and Persistence in Desert Ecosystems. mSystems 2020; 5:e00495-19. [PMID: 32291352 PMCID: PMC7159902 DOI: 10.1128/msystems.00495-19] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial life is surprisingly abundant and diverse in global desert ecosystems. In these environments, microorganisms endure a multitude of physicochemical stresses, including low water potential, carbon and nitrogen starvation, and extreme temperatures. In this review, we summarize our current understanding of the energetic mechanisms and trophic dynamics that underpin microbial function in desert ecosystems. Accumulating evidence suggests that dormancy is a common strategy that facilitates microbial survival in response to water and carbon limitation. Whereas photoautotrophs are restricted to specific niches in extreme deserts, metabolically versatile heterotrophs persist even in the hyper-arid topsoils of the Atacama Desert and Antarctica. At least three distinct strategies appear to allow such microorganisms to conserve energy in these oligotrophic environments: degradation of organic energy reserves, rhodopsin- and bacteriochlorophyll-dependent light harvesting, and oxidation of the atmospheric trace gases hydrogen and carbon monoxide. In turn, these principles are relevant for understanding the composition, functionality, and resilience of desert ecosystems, as well as predicting responses to the growing problem of desertification.
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Affiliation(s)
- Pok Man Leung
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
| | - Sean K Bay
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
| | - Dimitri V Meier
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Eleonora Chiri
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, University of Pretoria, Hatfield, Pretoria, South Africa
| | - Osnat Gillor
- Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Sde Boker, Israel
| | - Dagmar Woebken
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Clayton, Victoria, Australia
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Wang L, Liu Q, Wu X, Huang Y, Wise MJ, Liu Z, Wang W, Hu J, Wang C. Bioinformatics Analysis of Metabolism Pathways of Archaeal Energy Reserves. Sci Rep 2019; 9:1034. [PMID: 30705313 PMCID: PMC6355812 DOI: 10.1038/s41598-018-37768-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 12/13/2018] [Indexed: 11/08/2022] Open
Abstract
Energy storage compounds play crucial roles in prokaryotic physiology. Five chemical compounds have been identified in prokaryotes as energy reserves: polyphosphate (polyP), polyhydroxyalkanoates (PHAs), glycogen, wax ester (WE) and triacylglycerol (TAG). Currently, no systematic study of archaeal energy storage metabolism exists. In this study, we collected 427 archaeal reference sequences from UniProt database. A thorough pathway screening of energy reserves led to an overview of distribution patterns of energy metabolism in archaea. We also explored how energy metabolism might have impact on archaeal extremophilic phenotypes. Based on the systematic analyses of archaeal proteomes, we confirmed that metabolism pathways of polyP, PHAs and glycogen are present in archaea, but TAG and WE are completely absent. It was also confirmed that PHAs are tightly related to halophilic archaea with larger proteome size and higher GC contents, while polyP is mainly present in methanogens. In sum, this study systematically investigates energy storage metabolism in archaea and provides a clear correlation between energy metabolism and the ability to survive in extreme environments. With more genomic editing tools developed for archaea and molecular mechanisms unravelled for energy storage metabolisms (ESMs), there will be a better understanding of the unique lifestyle of archaea in extreme environments.
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Affiliation(s)
- Liang Wang
- Department of Bioinformatics, School of Medical Informatics, Xuzhou Medical University, Xuzhou, Jiangsu, China.
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, China.
| | - Qinghua Liu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Xiang Wu
- Department of Bioinformatics, School of Medical Informatics, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Yue Huang
- Department of Bioinformatics, School of Medical Informatics, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Michael J Wise
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth, Western Australia, Australia
- Department of Computer Science and Software Engineering, School of Physics, Mathematics and Computing, University of Western Australia, Perth, Western Australia, Australia
| | - Zhanzhong Liu
- Xuzhou Infectious Diseases Hospital, Xuzhou, Jiangsu, China
| | - Wei Wang
- Department of Bioinformatics, School of Medical Informatics, Xuzhou Medical University, Xuzhou, Jiangsu, China
- School of Public Health, Capital Medical University, Beijing, China
- School of Medical Sciences, Edith Cowan University, Perth, WA, Australia
| | - Junfeng Hu
- Department of Bioinformatics, School of Medical Informatics, Xuzhou Medical University, Xuzhou, Jiangsu, China
- Department of Computer Science, School of Medical Informatics, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Chunying Wang
- Xuzhou Infectious Diseases Hospital, Xuzhou, Jiangsu, China
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Santiago-Martínez MG, Encalada R, Lira-Silva E, Pineda E, Gallardo-Pérez JC, Reyes-García MA, Saavedra E, Moreno-Sánchez R, Marín-Hernández A, Jasso-Chávez R. The nutritional status of Methanosarcina acetivorans regulates glycogen metabolism and gluconeogenesis and glycolysis fluxes. FEBS J 2016; 283:1979-99. [PMID: 27000496 DOI: 10.1111/febs.13717] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 03/10/2016] [Accepted: 03/17/2016] [Indexed: 11/27/2022]
Abstract
Gluconeogenesis is an essential pathway in methanogens because they are unable to use exogenous hexoses as carbon source for cell growth. With the aim of understanding the regulatory mechanisms of central carbon metabolism in Methanosarcina acetivorans, the present study investigated gene expression, the activities and metabolic regulation of key enzymes, metabolite contents and fluxes of gluconeogenesis, as well as glycolysis and glycogen synthesis/degradation pathways. Cells were grown with methanol as a carbon source. Key enzymes were kinetically characterized at physiological pH/temperature. Active consumption of methanol during exponential cell growth correlated with significant methanogenesis, gluconeogenic flux and steady glycogen synthesis. After methanol exhaustion, cells reached the stationary growth phase, which correlated with the rise in glycogen consumption and glycolytic flux, decreased methanogenesis, negligible acetate production and an absence of gluconeogenesis. Elevated activities of carbon monoxide dehydrogenase/acetyl-CoA synthetase complex and pyruvate: ferredoxin oxidoreductase suggested the generation of acetyl-CoA and pyruvate for glycogen synthesis. In the early stationary growth phase, the transcript contents and activities of pyruvate phosphate dikinase, fructose 1,6-bisphosphatase and glycogen synthase decreased, whereas those of glycogen phosphorylase, ADP-phosphofructokinase and pyruvate kinase increased. Therefore, glycogen and gluconeogenic metabolites were synthesized when an external carbon source was provided. Once such a carbon source became depleted, glycolysis and methanogenesis fed by glycogen degradation provided the ATP supply. Weak inhibition of key enzymes by metabolites suggested that the pathways evaluated were mainly transcriptionally regulated. Because glycogen metabolism and glycolysis/gluconeogenesis are not present in all methanogens, the overall data suggest that glycogen storage might represent an environmental advantage for methanosarcinales when carbon sources are scarce. Also, the understanding of the central carbohydrate metabolism in methanosarcinales may help to optimize methane production.
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Affiliation(s)
| | - Rusely Encalada
- Departamento de Bioquímica, Instituto Nacional de Cardiología, México DF, México
| | - Elizabeth Lira-Silva
- Departamento de Bioquímica, Instituto Nacional de Cardiología, México DF, México
| | - Erika Pineda
- Departamento de Bioquímica, Instituto Nacional de Cardiología, México DF, México
| | | | | | - Emma Saavedra
- Departamento de Bioquímica, Instituto Nacional de Cardiología, México DF, México
| | | | | | - Ricardo Jasso-Chávez
- Departamento de Bioquímica, Instituto Nacional de Cardiología, México DF, México
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5
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Lambie SC, Kelly WJ, Leahy SC, Li D, Reilly K, McAllister TA, Valle ER, Attwood GT, Altermann E. The complete genome sequence of the rumen methanogen Methanosarcina barkeri CM1. Stand Genomic Sci 2015; 10:57. [PMID: 26413197 PMCID: PMC4582637 DOI: 10.1186/s40793-015-0038-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 07/09/2015] [Indexed: 01/05/2023] Open
Abstract
Methanosarcina species are the most metabolically versatile of the methanogenic Archaea and can obtain energy for growth by producing methane via the hydrogenotrophic, acetoclastic or methylotrophic pathways. Methanosarcina barkeri CM1 was isolated from the rumen of a New Zealand Friesian cow grazing a ryegrass/clover pasture, and its genome has been sequenced to provide information on the phylogenetic diversity of rumen methanogens with a view to developing technologies for methane mitigation. The 4.5 Mb chromosome has an average G + C content of 39 %, and encodes 3523 protein-coding genes, but has no plasmid or prophage sequences. The gene content is very similar to that of M. barkeri Fusaro which was isolated from freshwater sediment. CM1 has a full complement of genes for all three methanogenesis pathways, but its genome shows many differences from those of other sequenced rumen methanogens. Consequently strategies to mitigate ruminant methane need to include information on the different methanogens that occur in the rumen.
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Affiliation(s)
- Suzanne C Lambie
- Rumen Microbiology, Animal Nutrition and Health, AgResearch Limited, Tennent Drive, Private Bag 11008, Palmerston North, 4442 New Zealand
| | - William J Kelly
- Rumen Microbiology, Animal Nutrition and Health, AgResearch Limited, Tennent Drive, Private Bag 11008, Palmerston North, 4442 New Zealand
| | - Sinead C Leahy
- Rumen Microbiology, Animal Nutrition and Health, AgResearch Limited, Tennent Drive, Private Bag 11008, Palmerston North, 4442 New Zealand ; New Zealand Agricultural Greenhouse Gas Research Centre, Grasslands Research Centre, Tennent Drive, Private Bag 11008, Palmerston North, 4442 New Zealand
| | - Dong Li
- Rumen Microbiology, Animal Nutrition and Health, AgResearch Limited, Tennent Drive, Private Bag 11008, Palmerston North, 4442 New Zealand
| | - Kerri Reilly
- Rumen Microbiology, Animal Nutrition and Health, AgResearch Limited, Tennent Drive, Private Bag 11008, Palmerston North, 4442 New Zealand
| | - Tim A McAllister
- Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, Alberta T1J 4B1 Canada
| | - Edith R Valle
- Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, Alberta T1J 4B1 Canada
| | - Graeme T Attwood
- Rumen Microbiology, Animal Nutrition and Health, AgResearch Limited, Tennent Drive, Private Bag 11008, Palmerston North, 4442 New Zealand ; New Zealand Agricultural Greenhouse Gas Research Centre, Grasslands Research Centre, Tennent Drive, Private Bag 11008, Palmerston North, 4442 New Zealand
| | - Eric Altermann
- Rumen Microbiology, Animal Nutrition and Health, AgResearch Limited, Tennent Drive, Private Bag 11008, Palmerston North, 4442 New Zealand ; Riddet Institute, Massey University, Palmerston North, 4442 New Zealand
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González-Cabaleiro R, Ofiţeru ID, Lema JM, Rodríguez J. Microbial catabolic activities are naturally selected by metabolic energy harvest rate. ISME JOURNAL 2015; 9:2630-41. [PMID: 26161636 DOI: 10.1038/ismej.2015.69] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 03/18/2015] [Accepted: 03/25/2015] [Indexed: 01/06/2023]
Abstract
The fundamental trade-off between yield and rate of energy harvest per unit of substrate has been largely discussed as a main characteristic for microbial established cooperation or competition. In this study, this point is addressed by developing a generalized model that simulates competition between existing and not experimentally reported microbial catabolic activities defined only based on well-known biochemical pathways. No specific microbial physiological adaptations are considered, growth yield is calculated coupled to catabolism energetics and a common maximum biomass-specific catabolism rate (expressed as electron transfer rate) is assumed for all microbial groups. Under this approach, successful microbial metabolisms are predicted in line with experimental observations under the hypothesis of maximum energy harvest rate. Two microbial ecosystems, typically found in wastewater treatment plants, are simulated, namely: (i) the anaerobic fermentation of glucose and (ii) the oxidation and reduction of nitrogen under aerobic autotrophic (nitrification) and anoxic heterotrophic and autotrophic (denitrification) conditions. The experimentally observed cross feeding in glucose fermentation, through multiple intermediate fermentation pathways, towards ultimately methane and carbon dioxide is predicted. Analogously, two-stage nitrification (by ammonium and nitrite oxidizers) is predicted as prevailing over nitrification in one stage. Conversely, denitrification is predicted in one stage (by denitrifiers) as well as anammox (anaerobic ammonium oxidation). The model results suggest that these observations are a direct consequence of the different energy yields per electron transferred at the different steps of the pathways. Overall, our results theoretically support the hypothesis that successful microbial catabolic activities are selected by an overall maximum energy harvest rate.
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Affiliation(s)
- Rebeca González-Cabaleiro
- Institute Centre for Water and Environment (iWATER), Department of Chemical and Environmental Engineering (CEE), Masdar Institute of Science and Technology, Abu Dhabi, UAE.,Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain
| | - Irina D Ofiţeru
- Institute Centre for Water and Environment (iWATER), Department of Chemical and Environmental Engineering (CEE), Masdar Institute of Science and Technology, Abu Dhabi, UAE
| | - Juan M Lema
- Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain
| | - Jorge Rodríguez
- Institute Centre for Water and Environment (iWATER), Department of Chemical and Environmental Engineering (CEE), Masdar Institute of Science and Technology, Abu Dhabi, UAE
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Ho KL, Chung YC, Lin YH, Tseng CP. Biofiltration of trimethylamine, dimethylamine, and methylamine by immobilized Paracoccus sp. CP2 and Arthrobacter sp. CP1. CHEMOSPHERE 2008; 72:250-256. [PMID: 18331754 DOI: 10.1016/j.chemosphere.2008.01.044] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Revised: 01/21/2008] [Accepted: 01/22/2008] [Indexed: 05/26/2023]
Abstract
A biofilter using granular activated carbon with immobilized Paracoccus sp. CP2 was applied to the elimination of 10-250 ppm of trimethylamine (TMA), dimethylamine (DMA), and methylamine (MA). The results indicated that the system effectively treated MA (>93%), DMA (>90%), and TMA (>85%) under high loading conditions, and the maximum degradation rates were 1.4, 1.2, and 0.9g-Nkg(-1) GAC d(-1). Among the three different amines treated, TMA was the most difficult to degrade and resulted in ammonia accumulation. Further study on TMA removal showed that the optimal pH was near neutral (6.0-8.0). The supply of high glucose (>0.1%) inhibited TMA removal, maybe due to substrate competition. However, complete TMA degradation was achieved under the co-immobilization of Paracoccus sp. CP2 and Arthrobacter sp. CP1 ( approximately 96%). Metabolite analysis results demonstrated that the metabolite NH(4)(+) concentrations decreased by a relatively small 27% while the metabolite NO(2)(-) apparently increased by heterotrophic nitrification of Arthrobacter sp. CP1 in the co-immobilization biofilter.
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Affiliation(s)
- Kuo-Ling Ho
- Department of Biological Science and Technology, National Chiao Tung University, Hsin-chu, Taiwan, Republic of China
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Maitra PK, Bhosale SB, Kshirsagar DC, Yeole TY, Shanbhag AN. Metabolite and enzyme profiles of glycogen metabolism in Methanococcoides methylutens. FEMS Microbiol Lett 2001; 198:23-9. [PMID: 11325549 DOI: 10.1111/j.1574-6968.2001.tb10614.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
When a buffered anaerobic cell suspension of Methanococcoides methylutens was maintained under methanol-limited conditions, intracellular glycogen and hexose phosphates were consumed rapidly and a very small amount of methane formed at 4 h of a starvation period. When methanol was supplemented after a total of 20 h of starvation, a reverse pattern was observed: the glycogen level and the hexose phosphate pool increased, and formation of methane took place after a lag period of 90 min. A considerable amount of methane was formed in 120 min after its detection with a rate of 0.18 micromol mg(-1) protein min(-1). When methane formation decreased after 270 min of incubation and finally came to a halt, probably due to complete assimilation of supplemented methanol, the levels of glycogen and hexose monophosphates decreased once again. However fructose 1,6-diphosphate levels showed a continuous increase even after exhaustion of methane formation. In contrast to the hexose phosphate pool, levels of other metabolites showed a small increase after addition of methanol. The enzyme profile of glycogen metabolism showed relatively high levels of triose phosphate isomerase. Glyceraldehyde 3-phosphate dehydrogenase reacted with NADPH with a three-fold higher activity as compared to that with NADH.
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Affiliation(s)
- P K Maitra
- Agharkar Research Institute, Agarkar Road, 411 004, Pune, India.
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10
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Interactions between nitrogen fixation and osmoregulation in the methanogenic archaeon methanosarcina barkeri 227. Appl Environ Microbiol 1999; 65:1222-7. [PMID: 10049887 PMCID: PMC91168 DOI: 10.1128/aem.65.3.1222-1227.1999] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The nitrogenase enzyme complex of Methanosarcina barkeri 227 was found to be more sensitive to NaCl than previously studied molybdenum nitrogenases are, with total inhibition of activity occurring at 190 mM NaCl, compared with >600 mM NaCl for Azotobacter vinelandii and Clostridium pasteurianum nitrogenases. Na+ and K+ had equivalent effects, whereas Mg2+ was more inhibitory than either monovalent cation, even on a per-charge basis. The anion Cl- was more inhibitory than acetate was. Because M. barkeri 227 is a facultative halophile, we examined the effects of external salt on growth and diazotrophy and found that inhibition of growth was not greater with N2 than with NH4+. Cells grown with N2 and cells grown with NH4+ produced equal concentrations of alpha-glutamate at low salt concentrations and equal concentrations of Nepsilon-acetyl-beta-lysine at NaCl concentrations greater than 500 mM. Despite the high energetic cost of fixing nitrogen for these osmolytes, we obtained no evidence that there is a shift towards nonnitrogenous osmolytes during diazotrophic growth. In vitro nitrogenase enzyme assays showed that at a low concentration (approximately 100 mM) potassium glutamate enhanced activity but at higher concentrations this compound inhibited activity; 50% inhibition occurred at a potassium glutamate concentration of approximately 400 mM.
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11
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Bock AK, Prieger-Kraft A, Sch�nheit P. Pyruvate ? a novel substrate for growth and methane formation in Methanosarcina barkeri. Arch Microbiol 1994. [DOI: 10.1007/bf00248891] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Abstract
Methanococcus maripaludis, a facultatively autotrophic archaebacterium that grows with H2 or formate as the electron donor, does not assimilate sugars and other complex organic substrates. However, glycogen is biosynthesized intracellularly and commonly reaches values of 0.34% of the cellular dry weight in the early stationary phase. To determine the pathway of glycogen catabolism, specific enzymes of sugar metabolism were assayed in cell extracts. The following enzymes were found (specific activity in milliunits per milligram of protein): glycogen phosphorylase, 4.4; phosphoglucomutase, 10; glucose-6-phosphate isomerase, 9; 6-phosphofructokinase, 5.6, fructose-1,6-bisphosphatase, 10; fructose-1,6-bisphosphate aldolase, 4.2; triosephosphate isomerase, 44; glyceraldehyde-3-phosphate dehydrogenase, 26; phosphoglycerate kinase, 20; phosphoglycerate mutase, 78; enolase, 107; and pyruvate kinase, 4.0. Glyceraldehyde-3-phosphate dehydrogenase was NADP+ dependent, and the pyruvate kinase required MnCl2. The 6-phosphofructokinase had an unusually low pH optimum of 6.0. Four nonoxidative pentose-biosynthetic enzymes were found (specific activity in milliunits per milligram of protein): transketolase, 12; transaldolase, 24; ribulose-5-phosphate-3-epimerase, 55; and ribulose-5-phosphate isomerase, 100. However, the key enzymes of the oxidative pentose phosphate pathway, the reductive pentose phosphate pathway, and the classical and modified Entner-Duodoroff pathways were not detected. Thus, glycogen appears to be catabolized by the Embden-Meyerhoff-Parnas pathway. This result is in striking contrast to the nonmethanogenic archaebacteria that have been examined, among which the Entner-Doudoroff pathway is common. A dithiothreitol-specific NADP(+)-reducing activity was also found (8.5 mU/mg of protein). Other thiol compounds, such as cysteine hydrochloride, reduced glutathione, and 2-mercaptoethanesulfonic acid, did not replace dithiothreitol for this activity. The physiological significance of this activity is not known.
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Affiliation(s)
- J P Yu
- Department of Microbiology, University of Georgia, Athens 30602-2605
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Kropinski AM, Ghiorse WC, Greenberg EP. The intracellular polyglucose storage granules of Spirochaeta aurantia. Arch Microbiol 1988. [DOI: 10.1007/bf00407794] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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