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Liu J, Xie S, Xu M, Jiang X, Wang Q, Zhao H, Zhang B. Screening the Protective Agents Able to Improve the Survival of Lactic Acid Bacteria Strains Subjected to Spray Drying Using Several Key Enzymes Responsible for Carbohydrate Utilization. Microorganisms 2024; 12:1094. [PMID: 38930476 PMCID: PMC11205755 DOI: 10.3390/microorganisms12061094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/22/2024] [Accepted: 05/24/2024] [Indexed: 06/28/2024] Open
Abstract
The aim of this study was to identify the most effective protectants for enhancing the viability of specific lactic acid bacteria (LAB) strains (Lactobacillus delbrueckii subsp. bulgaricus CICC 6097, Lactiplantibacillus plantarum CICC 21839, Lactobacillus acidophilus NCFM) by assessing their enzymatic activity when exposed to spray drying (inlet/outlet temperature: 135 °C/90 °C). Firstly, it was found that the live cell counts of the selected LAB cells from the 10% (w/v) recovered skim milk (RSM) group remained above 107 CFU/g after spray drying. Among all the three groups (1% w/v RSM group, 10% w/v RSM group, and control group), the two enzymes pyruvate kinase (PK) and lactate dehydrogenase (LDH) were more sensitive to spray drying than hexokinase (HK) and β-galactosidase (β-GAL). Next, transcriptome data of Lb. acidophilus NCFM showed that 10% (w/v) RSM improved the down-regulated expressions of genes encoding PK (pyk) and LDH (ldh) after spray drying compared to 1% (w/v) RSM. Finally, four composite protectants were created, each consisting of 10% (w/v) RSM plus a different additive-sodium glutamate (CP-A group), sucrose (CP-B group), trehalose (CP-C group), or a combination of sodium glutamate, sucrose, and trehalose (CP-D group)-to encapsulate Lb. acidophilus NCFM. It was observed that the viable counts of strain NCFM (8.56 log CFU/g) and enzymatic activity of PK and LDH in the CP-D group were best preserved compared to the other three groups. Therefore, our study suggested that measuring the LDH and PK activity could be used as a promising tool to screen the effective spray-dried protective agent for LAB cells.
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Affiliation(s)
| | | | | | | | | | | | - Bolin Zhang
- Beijing Key Laboratory of Forest Food Processing and Safety, College of Biological Science and Biotechnology, Beijing Forestry University, Beijing 100083, China; (J.L.); (S.X.); (M.X.); (X.J.); (Q.W.); (H.Z.)
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Singh L, Karthikeyan S, Thakur KG. Biochemical and structural characterization reveals Rv3400 codes for β-phosphoglucomutase in Mycobacterium tuberculosis. Protein Sci 2024; 33:e4943. [PMID: 38501428 PMCID: PMC10949319 DOI: 10.1002/pro.4943] [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: 08/25/2023] [Revised: 01/22/2024] [Accepted: 02/11/2024] [Indexed: 03/20/2024]
Abstract
Mycobacterium tuberculosis (Mtb) adapt to various host environments and utilize a variety of sugars and lipids as carbon sources. Among these sugars, maltose and trehalose, also play crucial role in bacterial physiology and virulence. However, some key enzymes involved in trehalose and maltose metabolism in Mtb are not yet known. Here we structurally and functionally characterized a conserved hypothetical gene Rv3400. We determined the crystal structure of Rv3400 at 1.7 Å resolution. The crystal structure revealed that Rv3400 adopts Rossmann fold and shares high structural similarity with haloacid dehalogenase family of proteins. Our comparative structural analysis suggested that Rv3400 could perform either phosphatase or pyrophosphatase or β-phosphoglucomutase (β-PGM) activity. Using biochemical studies, we further confirmed that Rv3400 performs β-PGM activity and hence, Rv3400 encodes for β-PGM in Mtb. Our data also confirm that Mtb β-PGM is a metal dependent enzyme having broad specificity for divalent metal ions. β-PGM converts β-D-glucose-1-phosphate to β-D-glucose-6-phosphate which is required for the generation of ATP and NADPH through glycolysis and pentose phosphate pathway, respectively. Using site directed mutagenesis followed by biochemical studies, we show that two Asp residues in the highly conserved DxD motif, D29 and D31, are crucial for enzyme activity. While D29A, D31A, D29E, D31E and D29N mutants lost complete activity, D31N mutant retained about 30% activity. This study further helps in understanding the role of β-PGM in the physiology of Mtb.
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Affiliation(s)
- Latika Singh
- Division of Protein Science and EngineeringCouncil of Scientific and Industrial Research—Institute of Microbial Technology (CSIR‐IMTECH)ChandigarhIndia
| | - Subramanian Karthikeyan
- Division of Protein Science and EngineeringCouncil of Scientific and Industrial Research—Institute of Microbial Technology (CSIR‐IMTECH)ChandigarhIndia
| | - Krishan Gopal Thakur
- Division of Protein Science and EngineeringCouncil of Scientific and Industrial Research—Institute of Microbial Technology (CSIR‐IMTECH)ChandigarhIndia
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Jackson SA, Duan M, Zhang P, Ihua MW, Stengel DB, Duan D, Dobson ADW. Isolation, identification, and biochemical characterization of a novel bifunctional phosphomannomutase/phosphoglucomutase from the metagenome of the brown alga Laminaria digitata. Front Microbiol 2022; 13:1000634. [PMID: 36212884 PMCID: PMC9537760 DOI: 10.3389/fmicb.2022.1000634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 08/15/2022] [Indexed: 11/17/2022] Open
Abstract
Macroalgae host diverse epiphytic bacterial communities with potential symbiotic roles including important roles influencing morphogenesis and growth of the host, nutrient exchange, and protection of the host from pathogens. Macroalgal cell wall structures, exudates, and intra-cellular environments possess numerous complex and valuable carbohydrates such as cellulose, hemi-cellulose, mannans, alginates, fucoidans, and laminarin. Bacterial colonizers of macroalgae are important carbon cyclers, acquiring nutrition from living macroalgae and also from decaying macroalgae. Seaweed epiphytic communities are a rich source of diverse carbohydrate-active enzymes which may have useful applications in industrial bioprocessing. With this in mind, we constructed a large insert fosmid clone library from the metagenome of Laminaria digitata (Ochrophyta) in which decay was induced. Subsequent sequencing of a fosmid clone insert revealed the presence of a gene encoding a bifunctional phosphomannomutase/phosphoglucomutase (PMM/PGM) enzyme 10L6AlgC, closely related to a protein from the halophilic marine bacterium, Cobetia sp. 10L6AlgC was subsequently heterologously expressed in Escherichia coli and biochemically characterized. The enzyme was found to possess both PMM and PGM activity, which had temperature and pH optima of 45°C and 8.0, respectively; for both activities. The PMM activity had a Km of 2.229 mM and Vmax of 29.35 mM min−1 mg−1, while the PGM activity had a Km of 0.5314 mM and a Vmax of 644.7 mM min−1 mg−1. Overall characterization of the enzyme including the above parameters as well as the influence of various divalent cations on these activities revealed that 10L6AlgC has a unique biochemical profile when compared to previously characterized PMM/PGM bifunctional enzymes. Thus 10L6AlgC may find utility in enzyme-based production of biochemicals with different potential industrial applications, in which other bacterial PMM/PGMs have previously been used such as in the production of low-calorie sweeteners in the food industry.
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Affiliation(s)
- Stephen A. Jackson
- School of Microbiology, University College Cork, Cork, Ireland
- Environmental Research Institute, University College Cork, Cork, Ireland
| | - Maohang Duan
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Pengyan Zhang
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Maureen W. Ihua
- School of Microbiology, University College Cork, Cork, Ireland
| | - Dagmar B. Stengel
- Botany and Plant Science, School of Natural Sciences, Ryan Institute for Environmental, Marine and Energy Research, University of Galway, Galway, Ireland
| | - Delin Duan
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
- *Correspondence: Delin Duan,
| | - Alan D. W. Dobson
- School of Microbiology, University College Cork, Cork, Ireland
- Environmental Research Institute, University College Cork, Cork, Ireland
- Alan D. W. Dobson,
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Ekkers DM, Tusso S, Moreno-Gamez S, Rillo MC, Kuipers OP, van Doorn GS. Trade-offs predicted by metabolic network structure give rise to evolutionary specialization and phenotypic diversification. Mol Biol Evol 2022; 39:msac124. [PMID: 35679426 PMCID: PMC9206417 DOI: 10.1093/molbev/msac124] [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: 06/08/2021] [Revised: 05/25/2022] [Accepted: 05/31/2022] [Indexed: 11/30/2022] Open
Abstract
Mitigating trade-offs between different resource-utilization functions is key to an organism's ecological and evolutionary success. These trade-offs often reflect metabolic constraints with a complex molecular underpinning; therefore, their consequences for evolutionary processes have remained elusive. Here, we investigate how metabolic architecture induces resource utilization constraints and how these constraints, in turn, elicit evolutionary specialization and diversification. Guided by the metabolic network structure of the bacterium Lactococcus cremoris, we selected two carbon sources (fructose and galactose) with predicted co-utilization constraints. By evolving L. cremoris on either fructose, galactose or a mix of both sugars, we imposed selection favoring divergent metabolic specializations or co-utilization of both resources, respectively. Phenotypic characterization revealed the evolution of either fructose or galactose specialists in the single-sugar treatments. In the mixed sugar regime, we observed adaptive diversification: both specialists coexisted, and no generalist evolved. Divergence from the ancestral phenotype occurred at key pathway junctions in the central carbon metabolism. Fructose specialists evolved mutations in the fbp and pfk genes that appear to balance anabolic and catabolic carbon fluxes. Galactose specialists evolved increased expression of pgmA (the primary metabolic bottleneck of galactose metabolism) and silencing of ptnABCD (the main glucose transporter) and ldh (regulator/enzyme of downstream carbon metabolism). Overall, our study shows how metabolic network architecture and historical contingency serve to predict targets of selection and inform the functional interpretation of evolved mutations. The elucidation of the relationship between molecular constraints and phenotypic trade-offs contributes to an integrative understanding of evolutionary specialization and diversification.
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Affiliation(s)
- David M Ekkers
- Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Sergio Tusso
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Grosshaderner Str. 2, 82152 Planegg-Martinsried, Germany
- Science for Life Laboratories and Department of Evolutionary Biology, Norbyvägen 18D, Uppsala University, 75236 Uppsala, Sweden
| | - Stefany Moreno-Gamez
- Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Marina C Rillo
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University Oldenburg, Schleusenstr. 1, 26382 Wilhelmshaven, Germany
| | - Oscar P Kuipers
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - G Sander van Doorn
- Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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Handling Several Sugars at a Time: a Case Study of Xyloglucan Utilization by Ruminiclostridium cellulolyticum. mBio 2021; 12:e0220621. [PMID: 34749527 PMCID: PMC8576529 DOI: 10.1128/mbio.02206-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Xyloglucan utilization by Ruminiclostridium cellulolyticum was formerly shown to imply the uptake of large xylogluco-oligosaccharides, followed by cytosolic depolymerization into glucose, galactose, xylose, and cellobiose. This raises the question of how the anaerobic bacterium manages the simultaneous presence of multiple sugars. Using genetic and biochemical approaches targeting the corresponding metabolic pathways, we observed that, surprisingly, all sugars are catabolized, collectively, but glucose consumption is prioritized. Most selected enzymes display unusual features, especially the GTP-dependent hexokinase of glycolysis, which appeared reversible and crucial for xyloglucan utilization. In contrast, mutant strains lacking either galactokinase, cellobiose-phosphorylase, or xylulokinase still catabolize xyloglucan but display variably altered growth. Furthermore, the xylogluco-oligosaccharide depolymerization process appeared connected to the downstream pathways through an intricate network of competitive and noncompetitive inhibitions. Altogether, our data indicate that xyloglucan utilization by R. cellulolyticum relies on an energy-saving central carbon metabolism deviating from current bacterial models, which efficiently prevents carbon overflow. IMPORTANCE The study of the decomposition of recalcitrant plant biomass is of great interest as the limiting step of terrestrial carbon cycle and to produce plant-derived valuable chemicals and energy. While extracellular cellulose degradation and catabolism have been studied in detail, few publications describe the complete metabolism of hemicelluloses and, to date, the published models are limited to the extracellular degradation and sequential entry of simple sugars. Here, we describe how the model anaerobic bacterium Ruminiclostridium cellulolyticum deals with the synchronous intracellular release of glucose, galactose, xylose, and cellobiose upon cytosolic depolymerization of imported xyloglucan oligosaccharides. The described novel metabolic strategy involves the simultaneous activity of different metabolic pathways coupled to a network of inhibitions controlling the carbon flux and is distinct from the ubiquitously observed sequential uptake and metabolism of carbohydrates known as the diauxic shift. Our results highlight the diversity of cellular responses related to a complex environment.
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Cellular Mn/Zn Ratio Influences Phosphoglucomutase Activity and Capsule Production in Streptococcus pneumoniae D39. J Bacteriol 2021; 203:e0060220. [PMID: 33875543 PMCID: PMC8316032 DOI: 10.1128/jb.00602-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Capsular polysaccharide (CPS) is a major virulence determinant for many human-pathogenic bacteria. Although the essential functional roles for CPS in bacterial virulence have been established, knowledge of how CPS production is regulated remains limited. Streptococcus pneumoniae (pneumococcus) CPS expression levels and overall thickness change in response to available oxygen and carbohydrate. These nutrients in addition to transition metal ions can vary significantly between host environmental niches and infection stage. Since the pneumococcus must modulate CPS expression among various host niches during disease progression, we examined the impact of the nutritional transition metal availability of manganese (Mn) and zinc (Zn) on CPS production. We demonstrate that increased Mn/Zn ratios increase CPS production via Mn-dependent activation of the phosphoglucomutase Pgm, an enzyme that functions at the branch point between glycolysis and the CPS biosynthetic pathway in a transcription-independent manner. Furthermore, we find that the downstream CPS protein CpsB, an Mn-dependent phosphatase, does not promote aberrant dephosphorylation of its target capsule-tyrosine kinase CpsD during Mn stress. Together, these data reveal a direct role for cellular Mn/Zn ratios in the regulation of CPS biosynthesis via the direct activation of Pgm. We propose a multilayer mechanism used by the pneumococcus in regulating CPS levels across various host niches. IMPORTANCE Evolving evidence strongly indicates that maintenance of metal homeostasis is essential for establishing colonization and continued growth of bacterial pathogens in the vertebrate host. In this study, we demonstrate the impact of cellular manganese/zinc (Mn/Zn) ratios on bacterial capsular polysaccharide (CPS) production, an important virulence determinant of many human-pathogenic bacteria, including Streptococcus pneumoniae. We show that higher Mn/Zn ratios increase CPS production via the Mn-dependent activation of the phosphoglucomutase Pgm, an enzyme that functions at the branch point between glycolysis and the CPS biosynthetic pathway. The findings provide a direct role for Mn/Zn homeostasis in the regulation of CPS expression levels and further support the ability of metal cations to act as important cellular signaling mediators in bacteria.
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Hatti-Kaul R, Chen L, Dishisha T, Enshasy HE. Lactic acid bacteria: from starter cultures to producers of chemicals. FEMS Microbiol Lett 2018; 365:5087731. [DOI: 10.1093/femsle/fny213] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/29/2018] [Indexed: 12/26/2022] Open
Affiliation(s)
- Rajni Hatti-Kaul
- Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden
| | - Lu Chen
- Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden
| | - Tarek Dishisha
- Department of Microbiology and Immunology, Faculty of Pharmacy, Beni-Suef University, 62511 Beni-Suef, Egypt
| | - Hesham El Enshasy
- Institute of Bioproduct Development (IBD), Universiti Teknologi Malaysia (UTM), 81 310 Skudai, Johor, Malaysia
- City of Scientific Research and Technology Applications, New Burg Al Arab, Alexandria, Egypt
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Zhang C, Allen KN, Dunaway-Mariano D. Mechanism of Substrate Recognition and Catalysis of the Haloalkanoic Acid Dehalogenase Family Member α-Phosphoglucomutase. Biochemistry 2018; 57:4504-4517. [PMID: 29952545 PMCID: PMC10725300 DOI: 10.1021/acs.biochem.8b00396] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
α-Phosphoglucomutase (αPGM), in its phosphorylated state, catalyzes the interconversion of α-d-glucose 1-phosphate and α-d-glucose 6-phosphate. The αPGM of Lactococcus lactis is a type C2B member of the haloalkanoic acid dehalogenase (HAD) enzyme family and is comprised of a Rossmann-fold catalytic domain and inserted α/β-fold cap domain. The active site is formed at the domain-domain interface. Herein, we report the results from a kinetic-based study of L. lactis αPGM catalysis, which demonstrate enzyme activation by autocatalyzed phosphorylation of Asp8 with αG1P, the intermediacy of αG1,6bisP in the phospho Ll-αPGM-catalyzed conversion of αG1P to G6P, and the reorientation of the αG1,6bisP intermediate via dissociation to solvent and rebinding. In order to provide insight into the structural determinants of L. lactis αPGM substrate recognition and catalysis, metal cofactor and substrate specificities were determined as were the contributions made by active-site residues toward catalytic efficiency. Lastly, the structure and catalytic mechanism of L. lactis αPGM are compared with those of HAD family phosphomutases L. lactis β-phosphoglucomutase and eukayotic α-phosphomannomutase to provide insight into the evolution of phosphohexomutases from HAD family phosphatases.
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Affiliation(s)
- Chunchun Zhang
- Testing & Analytical Center, Sichuan University, Chengdu, Sichuan 610064, P. R. China
| | - Karen N. Allen
- Department of Chemistry, Boston University, Boston MA 02215-2521
| | - Debra Dunaway-Mariano
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131
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Zeidan AA, Poulsen VK, Janzen T, Buldo P, Derkx PMF, Øregaard G, Neves AR. Polysaccharide production by lactic acid bacteria: from genes to industrial applications. FEMS Microbiol Rev 2017; 41:S168-S200. [DOI: 10.1093/femsre/fux017] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 03/29/2017] [Indexed: 01/14/2023] Open
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Derkaoui M, Antunes A, Nait Abdallah J, Poncet S, Mazé A, Ma Pham QM, Mokhtari A, Deghmane AE, Joyet P, Taha MK, Deutscher J. Transport and Catabolism of Carbohydrates by Neisseria meningitidis. J Mol Microbiol Biotechnol 2016; 26:320-32. [DOI: 10.1159/000447093] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/25/2016] [Indexed: 11/19/2022] Open
Abstract
We identified the genes encoding the proteins for the transport of glucose and maltose in <i>Neisseria meningitidis</i> strain 2C4-3. A mutant deleted for <i>NMV_1892</i><i>(glcP)</i> no longer grew on glucose and deletion of <i>NMV_0424</i><i>(malY)</i> prevented the utilization of maltose. We also purified and characterized glucokinase and α-phosphoglucomutase, which catalyze early catabolic steps of the two carbohydrates. <i>N. meningitidis</i> catabolizes the two carbohydrates either via the Entner-Doudoroff (ED) pathway or the pentose phosphate pathway, thereby forming glyceraldehyde-3-P and either pyruvate or fructose-6-P, respectively. We purified and characterized several key enzymes of the two pathways. The genes required for the transformation of glucose into gluconate-6-P and its further catabolism via the ED pathway are organized in two adjacent operons. <i>N. meningitidis</i> also contains genes encoding proteins which exhibit similarity to the gluconate transporter <i>(NMV_2230)</i> and gluconate kinase <i>(NMV_2231)</i> of Enterobacteriaceae and Firmicutes. However, gluconate might not be the real substrate of <i>NMV_2230</i> because <i>N. meningitidi</i>s was not able to grow on gluconate as the sole carbon source. Surprisingly, deletion of <i>NMV_2230</i> stimulated growth in minimal medium in the presence and absence of glucose and drastically slowed the clearance of <i>N. meningitidis</i> cells from transgenic mice after intraperitoneal challenge.
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Paixão L, Caldas J, Kloosterman TG, Kuipers OP, Vinga S, Neves AR. Transcriptional and metabolic effects of glucose on Streptococcus pneumoniae sugar metabolism. Front Microbiol 2015; 6:1041. [PMID: 26500614 PMCID: PMC4595796 DOI: 10.3389/fmicb.2015.01041] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 09/14/2015] [Indexed: 11/13/2022] Open
Abstract
Streptococcus pneumoniae is a strictly fermentative human pathogen that relies on carbohydrate metabolism to generate energy for growth. The nasopharynx colonized by the bacterium is poor in free sugars, but mucosa lining glycans can provide a source of sugar. In blood and inflamed tissues glucose is the prevailing sugar. As a result during progression from colonization to disease S. pneumoniae has to cope with a pronounced shift in carbohydrate nature and availability. Thus, we set out to assess the pneumococcal response to sugars found in glycans and the influence of glucose (Glc) on this response at the transcriptional, physiological, and metabolic levels. Galactose (Gal), N-acetylglucosamine (GlcNAc), and mannose (Man) affected the expression of 8 to 14% of the genes covering cellular functions including central carbon metabolism and virulence. The pattern of end-products as monitored by in vivo13C-NMR is in good agreement with the fermentation profiles during growth, while the pools of phosphorylated metabolites are consistent with the type of fermentation observed (homolactic vs. mixed) and regulation at the metabolic level. Furthermore, the accumulation of α-Gal6P and Man6P indicate metabolic bottlenecks in the metabolism of Gal and Man, respectively. Glc added to cells actively metabolizing other sugar(s) was readily consumed and elicited a metabolic shift toward a homolactic profile. The transcriptional response to Glc was large (over 5% of the genome). In central carbon metabolism (most represented category), Glc exerted mostly negative regulation. The smallest response to Glc was observed on a sugar mix, suggesting that exposure to varied sugars improves the fitness of S. pneumoniae. The expression of virulence factors was negatively controlled by Glc in a sugar-dependent manner. Overall, our results shed new light on the link between carbohydrate metabolism, adaptation to host niches and virulence.
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Affiliation(s)
- Laura Paixão
- Laboratory of Lactic Acid Bacteria and In Vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Oeiras, Portugal
| | - José Caldas
- Center of Intelligent Systems, Instituto de Engenharia Mecânica, Instituto Superior Técnico, Universidade de Lisboa Lisboa, Portugal
| | - Tomas G Kloosterman
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands
| | - Susana Vinga
- Center of Intelligent Systems, Instituto de Engenharia Mecânica, Instituto Superior Técnico, Universidade de Lisboa Lisboa, Portugal
| | - Ana R Neves
- Laboratory of Lactic Acid Bacteria and In Vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa Oeiras, Portugal
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Characterization and upregulation of bifunctional phosphoglucomutase/phosphomannomutase enzyme in an exobiopolymer overproducing strain of Acinetobacter haemolyticus. Microbiol Res 2015; 181:8-14. [PMID: 26640047 DOI: 10.1016/j.micres.2015.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Revised: 07/13/2015] [Accepted: 08/04/2015] [Indexed: 11/24/2022]
Abstract
Several members of the Acinetobacter spp. produce exobiopolymer (EBP) of considerable biotechnological interest. In a previous study, we reported phosphate removal capacity of EBP produced by Acinetobacter haemolyticus. Insertional mutagenesis was attempted to develop EBP-overproducing strains of A. haemolyticus and mutant MG606 was isolated. In order to understand the underlying mechanism of overproduction, the EBP overproducing mutant MG606 was analyzed and compared with the wild type counterpart for its key EBP synthetic enzymes. The EBP produced by MG606 mutant was 650 mg/L compared to 220 mg/L in its wild type counterpart. Significantly high (p<0.05) levels of phosphoglucomutase/phosphomannomutase (PGM/PMM) in MG606 mutant was noted, whereas activities of other enzymes responsible for EBP synthesis showed no significant change (p>0.05). The up-regulation of PGM/PMM expression in mutant was further confirmed by real time reverse transcriptase (RT)-PCR of PGM/PMM transcripts. The optimal conditions for PGM/PMM activity were found to be 35 °C and pH 7.5; PGM/PMM activity was inhibited by ions such as lithium, zinc, nickel. Further, incubation of cells with a PGM inhibitor (lithium) resulted in a concentration-dependent decrease in EBP production further confirming the role of PGM/PMM overexpression in enhanced EBP production by the mutant. Overall the results of our study indicate a key role of PGM/PMM in enhanced EBP production, as evident from enhanced enzyme activity, increased PGM/PMM transcripts and reduction in EBP synthesis by a PGM inhibitor. We envisage a potential exploitation of the insights so obtained to effectively engineer strains of Acinetobacter for overproducing phosphate binding EBP.
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Kim HR, Park SY, Kim SB, Jeong H, Choi SK, Park SH. Inactivation of the phosphoglucomutase gene pgm in Paenibacillus polymyxa leads to overproduction of fusaricidin. ACTA ACUST UNITED AC 2014; 41:1405-14. [DOI: 10.1007/s10295-014-1470-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 05/28/2014] [Indexed: 11/29/2022]
Abstract
Abstract
Fusaricidin, a lipodepsipeptide isolated from Paenibacillus polymyxa, has high antimicrobial activity against fungi and Gram-positive bacteria. Through mutagenesis, we obtained two mutant strains, N1U7 and N17U7, which produce 6.2- to 7.9-fold more fusaricidin than their parent strain. Causal mutations were identified by whole-genome sequencing, and the two strains each contained at least eleven point mutations, including four common mutations. A mutation in the PPE04441 gene (pgm), encoding an α-phosphoglucomutase, was found to be an important factor in fusaricidin overproduction by complementation experiments. Null mutation of pgm in the parental strain increased fusaricidin production by 5.2-fold. Increased growth and cell viability in stationary phase, reduced exopolysaccharide production, and increased fusA expression were observed in the pgm mutant strains, which might be related to fusaricidin overproduction. This is the first report revealing that PGM deficiency leads to an overproduction of fusaricidin.
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Affiliation(s)
- Ha-Rim Kim
- grid.249967.7 0000000406363099 Super-Bacteria Research Center Korea Research Institute of Bioscience and Biotechnology (KRIBB) 125 Gwahak-ro 305-806 Daejeon Yuseong-gu Republic of Korea
- grid.412786.e 0000000417918264 Biosystems and Bioengineering Program Korea University of Science and Technology (UST) 217 Gajung-ro 305-350 Daejeon Yuseong-gu Republic of Korea
| | - Soo-Young Park
- grid.249967.7 0000000406363099 Super-Bacteria Research Center Korea Research Institute of Bioscience and Biotechnology (KRIBB) 125 Gwahak-ro 305-806 Daejeon Yuseong-gu Republic of Korea
| | - Seong-Bin Kim
- grid.249967.7 0000000406363099 Super-Bacteria Research Center Korea Research Institute of Bioscience and Biotechnology (KRIBB) 125 Gwahak-ro 305-806 Daejeon Yuseong-gu Republic of Korea
| | - Haeyoung Jeong
- grid.249967.7 0000000406363099 Korean Bioinformation Center, KRIBB 125 Gwahak-ro 305-806 Daejeon Yuseong-gu Republic of Korea
- grid.412786.e 0000000417918264 Biosystems and Bioengineering Program Korea University of Science and Technology (UST) 217 Gajung-ro 305-350 Daejeon Yuseong-gu Republic of Korea
| | - Soo-Keun Choi
- grid.249967.7 0000000406363099 Super-Bacteria Research Center Korea Research Institute of Bioscience and Biotechnology (KRIBB) 125 Gwahak-ro 305-806 Daejeon Yuseong-gu Republic of Korea
- grid.412786.e 0000000417918264 Biosystems and Bioengineering Program Korea University of Science and Technology (UST) 217 Gajung-ro 305-350 Daejeon Yuseong-gu Republic of Korea
| | - Seung-Hwan Park
- grid.249967.7 0000000406363099 Super-Bacteria Research Center Korea Research Institute of Bioscience and Biotechnology (KRIBB) 125 Gwahak-ro 305-806 Daejeon Yuseong-gu Republic of Korea
- grid.412786.e 0000000417918264 Biosystems and Bioengineering Program Korea University of Science and Technology (UST) 217 Gajung-ro 305-350 Daejeon Yuseong-gu Republic of Korea
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14
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From physiology to systems metabolic engineering for the production of biochemicals by lactic acid bacteria. Biotechnol Adv 2013; 31:764-88. [DOI: 10.1016/j.biotechadv.2013.03.011] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 03/28/2013] [Accepted: 03/31/2013] [Indexed: 11/21/2022]
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Nogly P, Matias PM, de Rosa M, Castro R, Santos H, Neves AR, Archer M. High-resolution structure of an atypical α-phosphoglucomutase related to eukaryotic phosphomannomutases. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:2008-16. [DOI: 10.1107/s0907444913017046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 06/19/2013] [Indexed: 11/10/2022]
Abstract
The first structure of a bacterial α-phosphoglucomutase with an overall fold similar to eukaryotic phosphomannomutases is reported. Unlike most α-phosphoglucomutases within the α-D-phosphohexomutase superfamily, it belongs to subclass IIb of the haloacid dehalogenase superfamily (HADSF). It catalyzes the reversible conversion of α-glucose 1-phosphate to glucose 6-phosphate. The crystal structure of α-phosphoglucomutase fromLactococcus lactis(APGM) was determined at 1.5 Å resolution and contains a sulfate and a glycerol bound at the enzyme active site that partially mimic the substrate. A dimeric form of APGM is present in the crystal and in solution, an arrangement that may be functionally relevant. The catalytic mechanism of APGM and its strict specificity towards α-glucose 1-phosphate are discussed.
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16
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Nogly P, Castro R, de Rosa M, Neves AR, Santos H, Archer M. Production and crystallization of α-phosphoglucomutase from Lactococcus lactis. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:1113-5. [PMID: 22949208 PMCID: PMC3433211 DOI: 10.1107/s1744309112032629] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 07/18/2012] [Indexed: 11/10/2022]
Abstract
α-Phosphoglucomutase (α-PGM) is an enzyme that is essential for the growth of Lactococcus lactis. The enzyme links bacterial anabolism with sugar utilization through glycolysis by catalyzing the reversible interconversion of glucose 6-phosphate and α-glucose 1-phosphate. The gene encoding α-PGM was cloned and overexpressed in L. lactis. The purified protein was functionally active and was crystallized with ammonium sulfate as a precipitant using vapour-diffusion and seeding techniques. Optimized crystals diffracted to 1.5 Å resolution at a synchrotron source.
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Affiliation(s)
- Przemyslaw Nogly
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa (ITQB–UNL), Avenida da República, 2780-157 Oeiras, Portugal
| | - Rute Castro
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa (ITQB–UNL), Avenida da República, 2780-157 Oeiras, Portugal
| | - Matteo de Rosa
- Instituto Gulbenkian de Ciência (IGC), 2780-156 Oeiras, Portugal
| | - Ana Rute Neves
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa (ITQB–UNL), Avenida da República, 2780-157 Oeiras, Portugal
| | - Helena Santos
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa (ITQB–UNL), Avenida da República, 2780-157 Oeiras, Portugal
| | - Margarida Archer
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa (ITQB–UNL), Avenida da República, 2780-157 Oeiras, Portugal
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A specific mutation in the promoter region of the silent cel cluster accounts for the appearance of lactose-utilizing Lactococcus lactis MG1363. Appl Environ Microbiol 2012; 78:5612-21. [PMID: 22660716 DOI: 10.1128/aem.00455-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The Lactococcus lactis laboratory strain MG1363 has been described to be unable to utilize lactose. However, in a rich medium supplemented with lactose as the sole carbon source, it starts to grow after prolonged incubation periods. Transcriptome analyses showed that L. lactis MG1363 Lac(+) cells expressed celB, encoding a putative cellobiose-specific phosphotransferase system (PTS) IIC component, which is normally silent in MG1363 Lac(-) cells. Nucleotide sequence analysis of the cel cluster of a Lac(+) isolate revealed a change from one of the guanines to adenine in the promoter region. We showed here that one particular mutation, taking place at increased frequency, accounts for the lactose-utilizing phenotype occurring in MG1363 cultures. The G-to-A transition creates a -10 element at an optimal distance from the -35 element. Thus, a fully active promoter is created, allowing transcription of the otherwise cryptic cluster. Nuclear magnetic resonance (NMR) spectroscopy results show that MG1363 Lac(+) uses a novel pathway of lactose utilization.
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The Lcn972 bacteriocin-encoding plasmid pBL1 impairs cellobiose metabolism in Lactococcus lactis. Appl Environ Microbiol 2011; 77:7576-85. [PMID: 21890668 DOI: 10.1128/aem.06107-11] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
pBL1 is a Lactococcus lactis theta-replicating 10.9-kbp plasmid that encodes the synthetic machinery of the bacteriocin Lcn972. In this work, the transcriptomes of exponentially growing L. lactis strains with and without pBL1 were compared. A discrete response was observed, with a total of 10 genes showing significantly changed expression. Upregulation of the lactococcal oligopeptide uptake (opp) system was observed, which was likely linked to a higher nitrogen demand required for Lcn972 biosynthesis. Strikingly, celB, coding for the membrane porter IIC of the cellobiose phosphoenolpyruvate-dependent phosphotransferase system (PTS), and the upstream gene llmg0186 were downregulated. Growth profiles for L. lactis strains MG1363, MG1363/pBL1, and MG1363 ΔcelB grown in chemically defined medium (CDM) containing cellobiose confirmed slower growth of MG1363/pBL1 and MG1363 ΔcelB, while no differences were observed with growth on glucose. The presence of pBL1 shifted the fermentation products toward a mixed acid profile and promoted substantial changes in intracellular pool sizes for glycolytic intermediates in cells growing on cellobiose as determined by high-pressure liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). Overall, these data support the genetic evidence of a constriction in cellobiose uptake. Notably, several cell wall precursors accumulated, while other UDP-activated sugar pools were lower, which could reflect rerouting of precursors toward the production of structural or storage polysaccharides. Moreover, cells growing slowly on cellobiose and those lacking celB were more tolerant to Lcn972 than cellobiose-adapted cells. Thus, downregulation of celB could help to build up a response against the antimicrobial activity of Lcn972, enhancing self-immunity of the producer cells.
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Sanfélix-Haywood N, Coll-Marqués JM, Yebra MJ. Role of α-phosphoglucomutase and phosphoglucose isomerase activities at the branching point between sugar catabolism and anabolism in Lactobacillus casei. J Appl Microbiol 2011; 111:433-42. [PMID: 21605291 DOI: 10.1111/j.1365-2672.2011.05045.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To evaluate the role of α-phosphoglucomutase (α-Pgm) and phosphoglucose isomerase (Pgi) activities in growth rate, sugar-phosphates, UDP-sugars and lactate biosynthesis in Lactobacillus casei. METHODS AND RESULTS The pgm and pgi genes coding for α-Pgm and Pgi activities in L. casei BL23, respectively, were identified, cloned and shown to be functional by homologous overexpression. In MRS fermentation medium with glucose, overexpression of pgm gene in L. casei resulted in a growth rate reduced to 75% and glucose-6P levels reduced to 47%. By contrast, with lactose, the growth rate was raised to 119%. An increment of α-Pgm activity had no significant effect on UDP-sugar levels. Remarkably, Pgi overexpression in L. casei grown in lactose or galactose resulted in almost a double growth rate with respect to the control strain. The increased Pgi activity also resulted in glucose-6P levels reduced to 25 and 59% of control strain cultured in glucose and lactose, respectively, and the fructose-6P levels were increased to 128% on glucose. UDP-glucose and UDP-galactose levels were reduced to 66 and 55%, respectively, of control strain levels cultured in galactose. In addition, the lactate yield increased to 115% in the strain overproducing Pgi grown in galactose. CONCLUSIONS The physiological amount of α-Pgm and Pgi activities is limited for L. casei growth on lactose, and lactose and galactose, respectively, and that limitation was overcome by pgm and pgi gene overexpression. The increment of α-Pgm and Pgi activities, respectively, resulted in modified levels of sugar-phosphates, sugar-nucleotides and lactate showing the modulation capacity of the carbon fluxes in L. casei at the level of the glycolytic intermediate glucose-6P. SIGNIFICANCE AND IMPACT OF THE STUDY Knowledge of the role of key enzymes in metabolic fluxes at the branching point between anabolic and catabolic pathways would allow a rational design of engineering strategies in L. casei.
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Affiliation(s)
- N Sanfélix-Haywood
- Laboratorio de Bacterias Lácticas y Probióticos, Instituto de Agroquímica y Tecnología de los Alimentos, IATA-CSIC, Valencia, Spain
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Kourtoglou E, Anasontzis GE, Mamma D, Topakas E, Hatzinikolaou DG, Christakopoulos P. Constitutive expression, purification and characterization of a phosphoglucomutase from Fusarium oxysporum. Enzyme Microb Technol 2011; 48:217-24. [DOI: 10.1016/j.enzmictec.2010.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 10/20/2010] [Accepted: 10/23/2010] [Indexed: 10/18/2022]
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Abstract
Accumulation of galactose in dairy products due to partial lactose fermentation by lactic acid bacteria yields poor-quality products and precludes their consumption by individuals suffering from galactosemia. This study aimed at extending our knowledge of galactose metabolism in Lactococcus lactis, with the final goal of tailoring strains for enhanced galactose consumption. We used directed genetically engineered strains to examine galactose utilization in strain NZ9000 via the chromosomal Leloir pathway (gal genes) or the plasmid-encoded tagatose 6-phosphate (Tag6P) pathway (lac genes). Galactokinase (GalK), but not galactose permease (GalP), is essential for growth on galactose. This finding led to the discovery of an alternative route, comprising a galactose phosphotransferase system (PTS) and a phosphatase, for galactose dissimilation in NZ9000. Introduction of the Tag6P pathway in a galPMK mutant restored the ability to metabolize galactose but did not sustain growth on this sugar. The latter strain was used to prove that lacFE, encoding the lactose PTS, is necessary for galactose metabolism, thus implicating this transporter in galactose uptake. Both PTS transporters have a low affinity for galactose, while GalP displays a high affinity for the sugar. Furthermore, the GalP/Leloir route supported the highest galactose consumption rate. To further increase this rate, we overexpressed galPMKT, but this led to a substantial accumulation of α-galactose 1-phosphate and α-glucose 1-phosphate, pointing to a bottleneck at the level of α-phosphoglucomutase. Overexpression of a gene encoding α-phosphoglucomutase alone or in combination with gal genes yielded strains with galactose consumption rates enhanced up to 50% relative to that of NZ9000. Approaches to further improve galactose metabolism are discussed.
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Castro R, Neves AR, Fonseca LL, Pool WA, Kok J, Kuipers OP, Santos H. Characterization of the individual glucose uptake systems of Lactococcus lactis: mannose-PTS, cellobiose-PTS and the novel GlcU permease. Mol Microbiol 2008; 71:795-806. [PMID: 19054326 DOI: 10.1111/j.1365-2958.2008.06564.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
According to previous reports, Lactococcus lactis imports glucose via two distinct phosphoenolpyruvate:phosphotransferase systems (mannose-PTS and cellobiose-PTS) and one or more unknown non-PTS permease(s). GlcU was identified as the sole non-PTS permease involved in the transport of glucose. Additionally, the biochemical properties of PTS(Man), PTS(Cel) and GlcU were characterized in double knockout mutants with glucose uptake restricted to a single system. Transport susceptibility to protonophores indicated that glucose uptake via GlcU is proton-motive force dependent. Competition assays revealed a high specificity of GlcU for glucose. Furthermore, the permease has low affinity for glucose and displays strong preference for the beta-anomer as shown by the profiles of consumption of the two glucose anomers studied by (13)C-NMR. Similar kinetic properties were found for PTS(Cel), while PTS(Man) is a high-affinity system recognizing equally well the two anomeric forms of glucose. Transcripts of the genes encoding the three transporters are present simultaneously in the parent strain NZ9000 as shown by reverse transcription-PCR. Investigation of the distribution of GlcU homologues among bacteria showed that these proteins are restricted to the low-GC Gram-positive Firmicutes. This work completes the identification of the glucose transport systems in L. lactis MG1363.
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Affiliation(s)
- Rute Castro
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Rua da Quinta Grande 6, Oeiras, Portugal
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