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Li H, Ramia NE, Borges F, Revol-Junelles AM, Vogensen FK, Leisner JJ. Identification of Potential Citrate Metabolism Pathways in Carnobacterium maltaromaticum. Microorganisms 2021; 9:microorganisms9102169. [PMID: 34683489 PMCID: PMC8537297 DOI: 10.3390/microorganisms9102169] [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] [Received: 09/25/2021] [Revised: 10/13/2021] [Accepted: 10/15/2021] [Indexed: 11/16/2022] Open
Abstract
In the present study, we describe the identification of potential citrate metabolism pathways for the lactic acid bacterium (LAB) Carnobacterium maltaromaticum. A phenotypic assay indicated that four of six C. maltaromaticum strains showed weak (Cm 6-1 and ATCC 35586) or even delayed (Cm 3-1 and Cm 5-1) citrate utilization activity. The remaining two strains, Cm 4-1 and Cm 1-2 gave negative results. Additional analysis showed no or very limited utilization of citrate in media containing 1% glucose and 22 or 30 mM citrate and inoculated with Cm 6-1 or ATCC 35586. Two potential pathways of citrate metabolism were identified by bioinformatics analyses in C. maltaromaticum including either oxaloacetate (pathway 1) or tricarboxylic compounds such as isocitrate and α-ketoglutarate (pathway 2) as intermediates. Genes encoding pathway 1 were present in two out of six strains while pathway 2 included genes present in all six strains. The two potential citrate metabolism pathways in C. maltaromaticum may potentially affect the sensory profiles of milk and soft cheeses subjected to growth with this species.
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Affiliation(s)
- Heng Li
- Pasteurien College, Soochow University, Suzhou 215123, China;
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-1870 Frederiksberg, Denmark
| | - Nancy E. Ramia
- Laboratoire d’Ingénierie des Biomolécules (LIBio), Ecole Nationale Supérieure d’Agronomie et des Industries Alimentaires (ENSAIA), Université de Lorraine, LIBio, F-54000 Nancy, France; (N.E.R.); (F.B.); (A.-M.R.-J.)
| | - Frédéric Borges
- Laboratoire d’Ingénierie des Biomolécules (LIBio), Ecole Nationale Supérieure d’Agronomie et des Industries Alimentaires (ENSAIA), Université de Lorraine, LIBio, F-54000 Nancy, France; (N.E.R.); (F.B.); (A.-M.R.-J.)
| | - Anne-Marie Revol-Junelles
- Laboratoire d’Ingénierie des Biomolécules (LIBio), Ecole Nationale Supérieure d’Agronomie et des Industries Alimentaires (ENSAIA), Université de Lorraine, LIBio, F-54000 Nancy, France; (N.E.R.); (F.B.); (A.-M.R.-J.)
| | - Finn Kvist Vogensen
- Department of Food Science, Faculty of Science, University of Copenhagen, DK-1958 Frederiksberg, Denmark;
| | - Jørgen J. Leisner
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-1870 Frederiksberg, Denmark
- Correspondence:
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2
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Terán LC, Mortera P, Tubio G, Alarcón SH, Blancato VS, Espariz M, Esteban L, Magni C. Genomic analysis revealed conserved acid tolerance mechanisms from native micro-organisms in fermented feed. J Appl Microbiol 2021; 132:1152-1165. [PMID: 34487594 DOI: 10.1111/jam.15292] [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: 01/07/2021] [Revised: 07/28/2021] [Accepted: 08/30/2021] [Indexed: 11/27/2022]
Abstract
AIMS Fermented feed is an agricultural practice used in many regions of the world to improve the growth performance of farm animals. This study aimed to identify and evaluate the lactic acid bacteria and yeast involved in the production of fermented feed. METHODS AND RESULTS We isolated and described two micro-organisms from autochthonous microbiota origin present in a regional feed product, Lactobacillus paracasei IBR07 (Lacticaseibacillus paracasei) and Kazachstania unispora IBR014 (Saccharomyces unisporum). Genome sequence analyses were performed to characterize both micro-organisms. Potential pathways involved in the acid response, tolerance and persistence were predicted in both genomes. Although L. paracasei and K. unispora are considered safe for animal feed, we analysed the presence of virulence factors, antibiotic resistance and pathogenicity islands. Furthermore, the Galleria mellonella model was used to support the safety of both isolates. CONCLUSIONS We conclude that IBR07 and IBR014 strains are good candidates to be used as starter cultures for feed fermentation. SIGNIFICANCE AND IMPACT OF THE STUDY The data presented here will be helpful to explore other biotechnological aspects and constitute a starting point for further studies to establish the consumption benefit of fermented feed in farm animal production.
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Affiliation(s)
- Lucrecia C Terán
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina.,Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los alimentos, FBioyF, UNR-Municipalidad de Granadero Baigorria, Rosario, Argentina.,Centro de Referencia para Lactobacilos, CERELA-CONICET, San Miguel de Tucuman, Tucumán, Argentina
| | - Pablo Mortera
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina.,Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los alimentos, FBioyF, UNR-Municipalidad de Granadero Baigorria, Rosario, Argentina
| | - Gisela Tubio
- Instituto de Procesos Biotecnológicos y Químicos Rosario, IPROByQ (CONICET-UNR), Rosario, Argentina
| | - Sergio H Alarcón
- Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los alimentos, FBioyF, UNR-Municipalidad de Granadero Baigorria, Rosario, Argentina.,Instituto de Química de Rosario, IQUIR (CONICET-UNR), Rosario, Argentina
| | - Victor S Blancato
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina.,Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los alimentos, FBioyF, UNR-Municipalidad de Granadero Baigorria, Rosario, Argentina
| | - Martín Espariz
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina.,Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los alimentos, FBioyF, UNR-Municipalidad de Granadero Baigorria, Rosario, Argentina.,Área Estadística y Procesamiento de Datos, Departamento de Matemática y Estadística, FBioyF-UNR, Rosario, Argentina
| | - Luis Esteban
- Química Biológica, Facultad de Ciencias Médicas, UNR, Rosario, Argentina
| | - Christian Magni
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina.,Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los alimentos, FBioyF, UNR-Municipalidad de Granadero Baigorria, Rosario, Argentina
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3
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Koendjbiharie JG, van Kranenburg R, Kengen SWM. The PEP-pyruvate-oxaloacetate node: variation at the heart of metabolism. FEMS Microbiol Rev 2021; 45:fuaa061. [PMID: 33289792 PMCID: PMC8100219 DOI: 10.1093/femsre/fuaa061] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 11/18/2020] [Indexed: 12/15/2022] Open
Abstract
At the junction between the glycolysis and the tricarboxylic acid cycle-as well as various other metabolic pathways-lies the phosphoenolpyruvate (PEP)-pyruvate-oxaloacetate node (PPO-node). These three metabolites form the core of a network involving at least eleven different types of enzymes, each with numerous subtypes. Obviously, no single organism maintains each of these eleven enzymes; instead, different organisms possess different subsets in their PPO-node, which results in a remarkable degree of variation, despite connecting such deeply conserved metabolic pathways as the glycolysis and the tricarboxylic acid cycle. The PPO-node enzymes play a crucial role in cellular energetics, with most of them involved in (de)phosphorylation of nucleotide phosphates, while those responsible for malate conversion are important redox enzymes. Variations in PPO-node therefore reflect the different energetic niches that organisms can occupy. In this review, we give an overview of the biochemistry of these eleven PPO-node enzymes. We attempt to highlight the variation that exists, both in PPO-node compositions, as well as in the roles that the enzymes can have within those different settings, through various recent discoveries in both bacteria and archaea that reveal deviations from canonical functions.
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Affiliation(s)
- Jeroen G Koendjbiharie
- Laboratory of Microbiology, Wageningen University, Stippeneng4, 6708 WE Wageningen, The Netherlands
| | - Richard van Kranenburg
- Laboratory of Microbiology, Wageningen University, Stippeneng4, 6708 WE Wageningen, The Netherlands
- Corbion, Arkelsedijk 46, 4206 AC Gorinchem, The Netherlands
| | - Servé W M Kengen
- Laboratory of Microbiology, Wageningen University, Stippeneng4, 6708 WE Wageningen, The Netherlands
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D'Angelo M, Martino GP, Blancato VS, Espariz M, Hartke A, Sauvageot N, Benachour A, Alarcón SH, Magni C. Diversity of volatile organic compound production from leucine and citrate in Enterococcus faecium. Appl Microbiol Biotechnol 2019; 104:1175-1186. [PMID: 31828406 DOI: 10.1007/s00253-019-10277-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/14/2019] [Accepted: 11/23/2019] [Indexed: 01/22/2023]
Abstract
Enterococcus faecium is frequently isolated from fermented food; in particular, they positively contribute to the aroma compound generation in traditional cheese. Citrate fermentation is a desirable property in these bacteria, but this feature is not uniformly distributed among E. faecium strains. In the present study, three selected E. faecium strains, IQ110 (cit-), GM70 (cit+ type I), and Com12 (cit+ type II), were analyzed in their production of aroma compounds in milk. End products and volatile organic compounds (VOCs) were determined by solid-phase micro-extraction combined with gas chromatography mass spectrometry (SPME-GC-MS). Principal component analysis (PCA) of aroma compound profiles revealed a different VOC composition for the three strains. In addition, resting cell experiments of E. faecium performed in the presence of leucine, citrate, or pyruvate as aroma compound precursors allowed us to determine metabolic differences between the studied strains. GM70 (cit+ type I) showed an active citrate metabolism, with increased levels of diacetyl and acetoin generation relative to Com12 or to citrate defective IQ110 strains. In addition, in the experimental conditions tested, a defective citrate-fermenting phenotype for the Com12 strain was found, while its leucine degradation and pyruvate metabolism were conserved. In conclusion, rational selection of E. faecium strains could be performed based on genotypic and phenotypic analyses. This would result in a performing strain, such as GM70, that could positively contribute to flavor, with typical notes of diacetyl, acetoin, 3-methyl butanal, and 3-methyl butanol in an adjuvant culture.
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Affiliation(s)
- Matilde D'Angelo
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Suipacha 590, Rosario, Argentina
- Instituto de Química de Rosario (IQUIR), FBioyF, UNR-CONICET, Suipacha 570, Rosario, Argentina
| | - Gabriela P Martino
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Suipacha 590, Rosario, Argentina
- Laboratorio de Biotecnología e Inocuidad de los Alimentos, FBioyF, UNR-Municipalidad de Granadero Baigorria, Sede Suipacha 590, Rosario, Argentina
| | - Victor S Blancato
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Suipacha 590, Rosario, Argentina
- Laboratorio de Biotecnología e Inocuidad de los Alimentos, FBioyF, UNR-Municipalidad de Granadero Baigorria, Sede Suipacha 590, Rosario, Argentina
- U2RM Stress/Virulence, Normandie Univ, UNICAEN, 14000, Caen, France
| | - Martín Espariz
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Suipacha 590, Rosario, Argentina
- Laboratorio de Biotecnología e Inocuidad de los Alimentos, FBioyF, UNR-Municipalidad de Granadero Baigorria, Sede Suipacha 590, Rosario, Argentina
- U2RM Stress/Virulence, Normandie Univ, UNICAEN, 14000, Caen, France
| | - Axel Hartke
- U2RM Stress/Virulence, Normandie Univ, UNICAEN, 14000, Caen, France
| | | | | | - Sergio H Alarcón
- Instituto de Química de Rosario (IQUIR), FBioyF, UNR-CONICET, Suipacha 570, Rosario, Argentina
- Laboratorio de Biotecnología e Inocuidad de los Alimentos, FBioyF, UNR-Municipalidad de Granadero Baigorria, Sede Suipacha 590, Rosario, Argentina
| | - Christian Magni
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Suipacha 590, Rosario, Argentina.
- Laboratorio de Biotecnología e Inocuidad de los Alimentos, FBioyF, UNR-Municipalidad de Granadero Baigorria, Sede Suipacha 590, Rosario, Argentina.
- U2RM Stress/Virulence, Normandie Univ, UNICAEN, 14000, Caen, France.
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Rozova ON, Mustakhimov II, But SY, Reshetnikov AS, Khmelenina VN. Role of the malic enzyme in metabolism of the halotolerant methanotroph Methylotuvimicrobium alcaliphilum 20Z. PLoS One 2019; 14:e0225054. [PMID: 31738793 PMCID: PMC6860931 DOI: 10.1371/journal.pone.0225054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 10/28/2019] [Indexed: 01/10/2023] Open
Abstract
The bacteria utilizing methane as a growth substrate (methanotrophs) are important constituents of the biosphere. Methanotrophs mitigate the emission of anthropogenic and natural greenhouse gas methane to the environment and are the promising agents for future biotechnologies. Many aspects of CH4 bioconversion by methanotrophs require further clarification. This study was aimed at characterizing the biochemical properties of the malic enzyme (Mae) from the halotolerant obligate methanotroph Methylotuvimicrobium alcaliphilum 20Z. The His6-tagged Mae was obtained by heterologous expression in Escherichia coli BL21 (DE3) and purified by affinity metal chelating chromatography. As determined by gel filtration and non-denaturating gradient gel electrophoresis, the molecular mass of the native enzyme is 260 kDa. The homotetrameric Mae (65x4 kDa) catalyzed an irreversible NAD+-dependent reaction of L-malate decarboxylation into pyruvate with a specific activity of 32 ± 2 units mg-1 and Km value of 5.5 ± 0.8 mM for malate and 57 ± 5 μM for NAD+. The disruption of the mae gene by insertion mutagenesis resulted in a 20-fold increase in intracellular malate level in the mutant compared to the wild type strain. Based on both enzyme and mutant properties, we conclude that the malic enzyme is involved in the control of intracellular L-malate level in Mtm. alcaliphilum 20Z. Genomic analysis has revealed that Maes present in methanotrophs fall into two different clades in the amino acid-based phylogenetic tree, but no correlation of the division with taxonomic affiliations of the host bacteria was observed.
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Affiliation(s)
- Olga N. Rozova
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Ildar I. Mustakhimov
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Sergei Y. But
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Aleksandr S. Reshetnikov
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Valentina N. Khmelenina
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
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Growth Dynamics and Survival of Liberibacter crescens BT-1, an Important Model Organism for the Citrus Huanglongbing Pathogen " Candidatus Liberibacter asiaticus". Appl Environ Microbiol 2019; 85:AEM.01656-19. [PMID: 31420343 PMCID: PMC6803310 DOI: 10.1128/aem.01656-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 08/12/2019] [Indexed: 11/20/2022] Open
Abstract
Liberibacter crescens is a bacterium that is closely related to plant pathogens that have caused billions of dollars in crop losses in recent years. Particularly devastating are citrus losses due to citrus greening disease, also known as Huanglongbing, which is caused by “Candidatus Liberibacter asiaticus” and carried by the Asian citrus psyllid. L. crescens is the only close relative of “Ca. Liberibacter asiaticus” that can currently be grown in culture, and it therefore serves as an important model organism for the growth, genetic manipulation, and biological control of the pathogenic species. Here, we show that one of the greatest limitations to L. crescens growth is the sharp increase in alkaline conditions it produces as a consequence of consumption of its preferred nutrient source. In addition to new information about L. crescens growth and metabolism, we provide new guidelines for culture conditions that improve the survival and yield of L. crescens. Liberibacter crescens is the only cultured member of its genus, which includes the devastating plant pathogen “Candidatus Liberibacter asiaticus,” associated with citrus greening/Huanglongbing (HLB). L. crescens has a larger genome and greater metabolic flexibility than “Ca. Liberibacter asiaticus” and the other uncultured plant-pathogenic Liberibacter species, and it is currently the best model organism available for these pathogens. L. crescens grows slowly and dies rapidly under current culture protocols and this extreme fastidiousness makes it challenging to study. We have determined that a major cause of rapid death of L. crescens in batch culture is its alkalinization of the medium (to pH 8.5 by the end of logarithmic phase). The majority of this alkalinization is due to consumption of alpha-ketoglutaric acid as its primary carbon source, with a smaller proportion of the pH rise due to NH3 production. Controlling the pH rise with higher buffering capacity and lower starting pH improved recoverability of cells from 10-day cultures by >1,000-fold. We have also performed a detailed analysis of L. crescens growth with total cell numbers calibrated to the optical density and the percentage of live and recoverable bacteria determined over 10-day time courses. We modified L. crescens culture conditions to greatly enhance survival and increase maximum culture density. The similarities between L. crescens and the pathogenic liberibacters make this work relevant to efforts to culture the latter organisms. Our results also suggest that growth-dependent pH alteration that overcomes medium buffering should always be considered when growing fastidious bacteria. IMPORTANCELiberibacter crescens is a bacterium that is closely related to plant pathogens that have caused billions of dollars in crop losses in recent years. Particularly devastating are citrus losses due to citrus greening disease, also known as Huanglongbing, which is caused by “Candidatus Liberibacter asiaticus” and carried by the Asian citrus psyllid. L. crescens is the only close relative of “Ca. Liberibacter asiaticus” that can currently be grown in culture, and it therefore serves as an important model organism for the growth, genetic manipulation, and biological control of the pathogenic species. Here, we show that one of the greatest limitations to L. crescens growth is the sharp increase in alkaline conditions it produces as a consequence of consumption of its preferred nutrient source. In addition to new information about L. crescens growth and metabolism, we provide new guidelines for culture conditions that improve the survival and yield of L. crescens.
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Implications of the expression of Enterococcus faecalis citrate fermentation genes during infection. PLoS One 2018; 13:e0205787. [PMID: 30335810 PMCID: PMC6193673 DOI: 10.1371/journal.pone.0205787] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 10/02/2018] [Indexed: 12/05/2022] Open
Abstract
Citrate is an ubiquitous compound in nature. However, citrate fermentation is present only in a few pathogenic or nonpathogenic microorganisms. The citrate fermentation pathway includes a citrate transporter, a citrate lyase complex, an oxaloacetate decarboxylase and a regulatory system. Enterococcus faecalis is commonly present in the gastro-intestinal microbiota of warm-blooded animals and insect guts. These bacteria can also cause infection and disease in immunocompromised individuals. In the present study, we performed whole genome analysis in Enterococcus strains finding that the complete citrate pathway is present in all of the E. faecalis strains isolated from such diverse habitats as animals, hospitals, water, milk, plants, insects, cheese, etc. These results indicate the importance of this metabolic preservation for persistence and growth of E. faecalis in different niches. We also analyzed the role of citrate metabolism in the E. faecalis pathogenicity. We found that an E. faecalis citrate fermentation-deficient strain was less pathogenic for Galleria mellonella larvae than the wild type. Furthermore, strains with deletions in the oxaloacetate decarboxylase subunits or in the α-acetolactate synthase resulted also less virulent than the wild type strain. We also observed that citrate promoters are induced in blood, urine and also in the hemolymph of G. mellonella. In addition, we showed that citrate fermentation allows E. faecalis to grow better in blood, urine and G. mellonella. The results presented here clearly indicate that citrate fermentation plays an important role in E. faecalis opportunistic pathogenic behavior.
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Torres Manno M, Zuljan F, Alarcón S, Esteban L, Blancato V, Espariz M, Magni C. Genetic and phenotypic features defining industrial relevant Lactococcus lactis, L. cremoris and L. lactis biovar. diacetylactis strains. J Biotechnol 2018; 282:25-31. [DOI: 10.1016/j.jbiotec.2018.06.345] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 06/22/2018] [Accepted: 06/22/2018] [Indexed: 12/11/2022]
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Alwazeer D, Riondet C, Cachon R. Comparison Between Fluorescent Probe and Ion-Selective Electrode Methods for Intracellular pH Determination in Leuconostoc mesenteroides. Curr Microbiol 2018; 75:1493-1497. [PMID: 30105525 DOI: 10.1007/s00284-018-1550-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 08/06/2018] [Indexed: 11/30/2022]
Abstract
The intracellular pH (pHin) of Leuconostoc mesenteroides subsp. mesenteroides 19D was evaluated by two different methods, fluorescent probe and ion-selective electrode. Two fluorescent probes 5 (and-6)-carboxyfluorescein diacetate succinimidyl ester (cFDASE) and 5 (and-6)-carboxy-2',7'-dichlorofluorescein diacetate succinimidyl ester (cDCFDASE) were tested to evaluate the intracellular pH (pHin) of living cells at a medium pH (pHex) ranged from 5.0 to 6.5. Salicylic acid was used as a probe for the ion-selective electrode method. Cells kept 60-80% of cFDASE probe at all pHex values against 5-10% of cDCFDASE probe at pHex ≤ 6.0. The pHin values measured by the ion-selective electrode were higher by 0.1-0.6 pH units at pHex ranged from 5.0 to 6.5 than those determinated by fluorescent probe method. The possibility to study the intracellular pH at a wide external pH range using a single probe, and the simplicity of the material and experimental protocol may make the ion-selective electrode method most useful and easy to measure the intracellular pH of lactic acid bacteria compared with the other techniques like fluorescent probes.
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Affiliation(s)
- Duried Alwazeer
- Research Center for Redox Applications in Foods (RCRAF), Iğdır University, 76000, Iğdır, Turkey.
| | - Christophe Riondet
- LGDP Laboratory of Genomes and Plant Development, Université de Perpignan, Perpignan, France
| | - Rémy Cachon
- UMR Procédés Alimentaires et Microbiologiques A 02.102 AgroSup Dijon - Université de Bourgogne, 1 Esplanade Erasme, 21000, Dijon, France
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The fumarylacetoacetate hydrolase (FAH) superfamily of enzymes: multifunctional enzymes from microbes to mitochondria. Biochem Soc Trans 2018; 46:295-309. [PMID: 29487229 DOI: 10.1042/bst20170518] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/23/2017] [Accepted: 01/02/2018] [Indexed: 11/17/2022]
Abstract
Prokaryotic and eukaryotic fumarylacetoacetate hydrolase (FAH) superfamily members, sharing conserved regions that form the so-called FAH-domain, catalyze a remarkable variety of reactions. These enzymes are essential in the metabolic pathways to degrade aromatic compounds in prokaryotes and eukaryotes. It appears that prokaryotic FAH superfamily members evolved mainly to allow microbes to generate energy and useful metabolites from complex carbon sources. We review recent findings, indicating that both prokaryotic and eukaryotic members of the FAH superfamily also display oxaloacetate decarboxylase (ODx) activity. The identification of human FAH domain-containing protein 1 as mitochondrial ODx regulating mitochondrial function supports the new concept that, during evolution, eukaryotic FAH superfamily members have acquired important regulatory functions beyond catabolism of complex carbon sources. Molecular studies on the evolution and function of FAH superfamily members are expected to provide new mechanistic insights in their physiological roles.
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Tronconi MA, Andreo CS, Drincovich MF. Chimeric Structure of Plant Malic Enzyme Family: Different Evolutionary Scenarios for NAD- and NADP-Dependent Isoforms. FRONTIERS IN PLANT SCIENCE 2018; 9:565. [PMID: 29868045 PMCID: PMC5958461 DOI: 10.3389/fpls.2018.00565] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 04/10/2018] [Indexed: 05/15/2023]
Abstract
Malic enzyme (ME) comprises a family of proteins with multiple isoforms located in different compartments of eukaryotic cells. In plants, cytosolic and plastidic enzymes share several characteristics such as NADP specificity (NADP-ME), oxaloacetate decarboxylase (OAD) activity, and homo-oligomeric assembly. However, mitochondrial counterparts are NAD-dependent proteins (mNAD-ME) lacking OAD activity, which can be structured as homo- and hetero-oligomers of two different subunits. In this study, we examined the molecular basis of these differences using multiple sequence analysis, structural modeling, and phylogenetic approaches. Plant mNAD-MEs show the lowest identity values when compared with other eukaryotic MEs with major differences including short amino acid insertions distributed throughout the primary sequence. Some residues in these exclusive segments are co-evolutionarily connected, suggesting that they could be important for enzymatic functionality. Phylogenetic analysis indicates that eukaryotes from different kingdoms used different strategies for acquiring the current set of NAD(P)-ME isoforms. In this sense, while the full gene family of vertebrates derives from the same ancestral gene, plant NADP-ME and NAD-ME isoforms have a distinct evolutionary history. Plant NADP-ME genes may have arisen from the α-protobacterial-like mitochondrial ancestor, a characteristic shared with major eukaryotic taxa. On the other hand, plant mNAD-ME genes were probably gained through an independent process involving the Archaeplastida ancestor. Finally, several residue signatures unique to all plant mNAD-MEs could be identified, some of which might be functionally connected to their exclusive biochemical properties. In light of these results, molecular evolutionary scenarios for these widely distributed enzymes in plants are discussed.
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Miguel-Romero L, Casino P, Landete JM, Monedero V, Zúñiga M, Marina A. The malate sensing two-component system MaeKR is a non-canonical class of sensory complex for C4-dicarboxylates. Sci Rep 2017; 7:2708. [PMID: 28577341 PMCID: PMC5457438 DOI: 10.1038/s41598-017-02900-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 04/20/2017] [Indexed: 11/09/2022] Open
Abstract
Microbial colonization of different environments is enabled to a great extent by the plasticity of their sensory mechanisms, among them, the two-component signal transduction systems (TCS). Here, an example of TCS plasticity is presented: the regulation of L-malate catabolism via malic enzyme by MaeRK in Lactobacillales. MaeKR belongs to the citrate family of TCS as the Escherichia coli DcuSR system. We show that the Lactobacillus casei histidine-kinase MaeK is defective in autophosphorylation activity as it lacks a functional catalytic and ATP binding domain. The cognate response regulator MaeR was poorly phosphorylated at its phosphoacceptor Asp in vitro. This phosphorylation, however, enhanced MaeR binding in vitro to its target sites and it was required for induction of regulated genes in vivo. Elucidation of the MaeR structure revealed that response regulator dimerization is accomplished by the swapping of α4-β5-α5 elements between two monomers, generating a phosphoacceptor competent conformation. Sequence and phylogenetic analyses showed that the MaeKR peculiarities are not exclusive to L. casei as they are shared by the rest of orthologous systems of Lactobacillales. Our results reveal MaeKR as a non-canonical TCS displaying distinctive features: a swapped response regulator and a sensor histidine kinase lacking ATP-dependent kinase activity.
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Affiliation(s)
- L Miguel-Romero
- Department of Genomic and Proteomic, Instituto de Biomedicina de Valencia (IBV-CSIC), Jaume Roig 11, 46010, Valencia, Spain
| | - P Casino
- Departamento de Bioquímica, Universitat de València, Dr Moliner 50, 46100, Burjassot, Spain.,Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED), Universitat de València, Dr Moliner 50, 46100, Burjassot, Spain
| | - J M Landete
- Departamento de Biotecnología de Alimentos, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Av. Agustín Escardino 7, 46980, Paterna, Valencia, Spain.,Departamento de Tecnología de Alimentos, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Carretera de La Coruña Km 7.5, 28040, Madrid, Spain
| | - V Monedero
- Departamento de Biotecnología de Alimentos, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Av. Agustín Escardino 7, 46980, Paterna, Valencia, Spain
| | - M Zúñiga
- Departamento de Biotecnología de Alimentos, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Av. Agustín Escardino 7, 46980, Paterna, Valencia, Spain.
| | - A Marina
- Department of Genomic and Proteomic, Instituto de Biomedicina de Valencia (IBV-CSIC), Jaume Roig 11, 46010, Valencia, Spain. .,Group 739 of the Centro de Investigación Biomédica en Red sobre Enfermedades Raras (CIBERER) del Instituto de Salud Carlos III, -, Spain.
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Monedero V, Revilla-Guarinos A, Zúñiga M. Physiological Role of Two-Component Signal Transduction Systems in Food-Associated Lactic Acid Bacteria. ADVANCES IN APPLIED MICROBIOLOGY 2017; 99:1-51. [PMID: 28438266 DOI: 10.1016/bs.aambs.2016.12.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Two-component systems (TCSs) are widespread signal transduction pathways mainly found in bacteria where they play a major role in adaptation to changing environmental conditions. TCSs generally consist of sensor histidine kinases that autophosphorylate in response to a specific stimulus and subsequently transfer the phosphate group to their cognate response regulators thus modulating their activity, usually as transcriptional regulators. In this review we present the current knowledge on the physiological role of TCSs in species of the families Lactobacillaceae and Leuconostocaceae of the group of lactic acid bacteria (LAB). LAB are microorganisms of great relevance for health and food production as the group spans from starter organisms to pathogens. Whereas the role of TCSs in pathogenic LAB (most of them belonging to the family Streptococcaceae) has focused the attention, the roles of TCSs in commensal LAB, such as most species of Lactobacillaceae and Leuconostocaceae, have been somewhat neglected. However, evidence available indicates that TCSs are key players in the regulation of the physiology of these bacteria. The first studies in food-associated LAB showed the involvement of some TCSs in quorum sensing and production of bacteriocins, but subsequent studies have shown that TCSs participate in other physiological processes, such as stress response, regulation of nitrogen metabolism, regulation of malate metabolism, and resistance to antimicrobial peptides, among others.
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Affiliation(s)
- Vicente Monedero
- Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Paterna, Spain
| | | | - Manuel Zúñiga
- Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Paterna, Spain
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Zuljan FA, Mortera P, Alarcón SH, Blancato VS, Espariz M, Magni C. Lactic acid bacteria decarboxylation reactions in cheese. Int Dairy J 2016. [DOI: 10.1016/j.idairyj.2016.07.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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15
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Blancato VS, Pagliai FA, Magni C, Gonzalez CF, Lorca GL. Functional Analysis of the Citrate Activator CitO from Enterococcus faecalis Implicates a Divalent Metal in Ligand Binding. Front Microbiol 2016; 7:101. [PMID: 26903980 PMCID: PMC4746285 DOI: 10.3389/fmicb.2016.00101] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/19/2016] [Indexed: 02/04/2023] Open
Abstract
The regulator of citrate metabolism, CitO, from Enterococcus faecalis belongs to the FCD family within the GntR superfamily. In the presence of citrate, CitO binds to cis-acting sequences located upstream of the cit promoters inducing the expression of genes involved in citrate utilization. The quantification of the molecular binding affinities, performed by isothermal titration calorimetry (ITC), indicated that CitO has a high affinity for citrate (KD = 1.2 ± 0.2 μM), while it did not recognize other metabolic intermediates. Based on a structural model of CitO where a putative small molecule and a metal binding site were identified, it was hypothesized that the metal ion is required for citrate binding. In agreement with this model, citrate binding to CitO sharply decreased when the protein was incubated with EDTA. This effect was reverted by the addition of Ni2+, and Zn2+ to a lesser extent. Structure-based site-directed mutagenesis was conducted and it was found that changes to alanine in residues Arg97 and His191 resulted in decreased binding affinities for citrate, as determined by EMSA and ITC. Further assays using lacZ fusions confirmed that these residues in CitO are involved in sensing citrate in vivo. These results indicate that the molecular modifications induced by a ligand and a metal binding in the C-terminal domain of CitO are required for optimal DNA binding activity, and consequently, transcriptional activation.
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Affiliation(s)
- Víctor S Blancato
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular de Rosario, Consejo Nacional de Investigaciones Científicas y TécnicasRosario, Argentina; Department of Microbiology and Cell Science, Genetics Institute, Institute of Food and Agricultural Science, University of FloridaGainesville, FL, USA
| | - Fernando A Pagliai
- Department of Microbiology and Cell Science, Genetics Institute, Institute of Food and Agricultural Science, University of Florida Gainesville, FL, USA
| | - Christian Magni
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas Rosario, Argentina
| | - Claudio F Gonzalez
- Department of Microbiology and Cell Science, Genetics Institute, Institute of Food and Agricultural Science, University of Florida Gainesville, FL, USA
| | - Graciela L Lorca
- Department of Microbiology and Cell Science, Genetics Institute, Institute of Food and Agricultural Science, University of Florida Gainesville, FL, USA
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Aroma compounds generation in citrate metabolism of Enterococcus faecium: Genetic characterization of type I citrate gene cluster. Int J Food Microbiol 2016; 218:27-37. [DOI: 10.1016/j.ijfoodmicro.2015.11.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 09/24/2015] [Accepted: 11/11/2015] [Indexed: 01/02/2023]
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17
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Ipe DS, Ben Zakour NL, Sullivan MJ, Beatson SA, Ulett KB, Benjamin WH, Davies MR, Dando SJ, King NP, Cripps AW, Schembri MA, Dougan G, Ulett GC. Discovery and Characterization of Human-Urine Utilization by Asymptomatic-Bacteriuria-Causing Streptococcus agalactiae. Infect Immun 2016; 84:307-19. [PMID: 26553467 PMCID: PMC4694007 DOI: 10.1128/iai.00938-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/01/2015] [Indexed: 12/27/2022] Open
Abstract
Streptococcus agalactiae causes both symptomatic cystitis and asymptomatic bacteriuria (ABU); however, growth characteristics of S. agalactiae in human urine have not previously been reported. Here, we describe a phenotype of robust growth in human urine observed in ABU-causing S. agalactiae (ABSA) that was not seen among uropathogenic S. agalactiae (UPSA) strains isolated from patients with acute cystitis. In direct competition assays using pooled human urine inoculated with equal numbers of a prototype ABSA strain, designated ABSA 1014, and any one of several UPSA strains, measurement of the percentage of each strain recovered over time showed a markedly superior fitness of ABSA 1014 for urine growth. Comparative phenotype profiling of ABSA 1014 and UPSA strain 807, isolated from a patient with acute cystitis, using metabolic arrays of >2,500 substrates and conditions revealed unique and specific l-malic acid catabolism in ABSA 1014 that was absent in UPSA 807. Whole-genome sequencing also revealed divergence in malic enzyme-encoding genes between the strains predicted to impact the activity of the malate metabolic pathway. Comparative growth assays in urine comparing wild-type ABSA and gene-deficient mutants that were functionally inactivated for the malic enzyme metabolic pathway by targeted disruption of the maeE or maeK gene in ABSA demonstrated attenuated growth of the mutants in normal human urine as well as synthetic human urine containing malic acid. We conclude that some S. agalactiae strains can grow in human urine, and this relates in part to malic acid metabolism, which may affect the persistence or progression of S. agalactiae ABU.
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Affiliation(s)
- Deepak S Ipe
- School of Medical Sciences, Menzies Health Institute Queensland, Griffith University, Gold Coast Campus, QLD, Australia
| | - Nouri L Ben Zakour
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Matthew J Sullivan
- School of Medical Sciences, Menzies Health Institute Queensland, Griffith University, Gold Coast Campus, QLD, Australia
| | - Scott A Beatson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Kimberly B Ulett
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - William H Benjamin
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Mark R Davies
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Samantha J Dando
- Institute for Glycomics, Griffith University, Gold Coast Campus, QLD, Australia
| | - Nathan P King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Allan W Cripps
- School of Medical Sciences, Menzies Health Institute Queensland, Griffith University, Gold Coast Campus, QLD, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Gordon Dougan
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Glen C Ulett
- School of Medical Sciences, Menzies Health Institute Queensland, Griffith University, Gold Coast Campus, QLD, Australia Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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18
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Spaans SK, Weusthuis RA, van der Oost J, Kengen SWM. NADPH-generating systems in bacteria and archaea. Front Microbiol 2015; 6:742. [PMID: 26284036 PMCID: PMC4518329 DOI: 10.3389/fmicb.2015.00742] [Citation(s) in RCA: 197] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 07/06/2015] [Indexed: 12/22/2022] Open
Abstract
Reduced nicotinamide adenine dinucleotide phosphate (NADPH) is an essential electron donor in all organisms. It provides the reducing power that drives numerous anabolic reactions, including those responsible for the biosynthesis of all major cell components and many products in biotechnology. The efficient synthesis of many of these products, however, is limited by the rate of NADPH regeneration. Hence, a thorough understanding of the reactions involved in the generation of NADPH is required to increase its turnover through rational strain improvement. Traditionally, the main engineering targets for increasing NADPH availability have included the dehydrogenase reactions of the oxidative pentose phosphate pathway and the isocitrate dehydrogenase step of the tricarboxylic acid (TCA) cycle. However, the importance of alternative NADPH-generating reactions has recently become evident. In the current review, the major canonical and non-canonical reactions involved in the production and regeneration of NADPH in prokaryotes are described, and their key enzymes are discussed. In addition, an overview of how different enzymes have been applied to increase NADPH availability and thereby enhance productivity is provided.
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Affiliation(s)
| | - Ruud A. Weusthuis
- Bioprocess Engineering, Wageningen UniversityWageningen, Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands
| | - Servé W. M. Kengen
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands
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Saigo M, Golic A, Alvarez CE, Andreo CS, Hogenhout SA, Mussi MA, Drincovich MF. Metabolic regulation of phytoplasma malic enzyme and phosphotransacetylase supports the use of malate as an energy source in these plant pathogens. MICROBIOLOGY-SGM 2014; 160:2794-2806. [PMID: 25294105 DOI: 10.1099/mic.0.083469-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Phytoplasmas ('Candidatus Phytoplasma') are insect-vectored plant pathogens. The genomes of these bacteria are small with limited metabolic capacities making them dependent on their plant and insect hosts for survival. In contrast to mycoplasmas and other relatives in the class Mollicutes, phytoplasmas encode genes for malate transporters and malic enzyme (ME) for conversion of malate into pyruvate. It was hypothesized that malate is probably a major energy source for phytoplasmas as these bacteria are limited in the uptake and processing of carbohydrates. In this study, we investigated the metabolic capabilities of 'Candidatus (Ca.) phytoplasma' aster yellows witches'-broom (AYWB) malic enzyme (ME). We found that AYWB-ME has malate oxidative decarboxylation activity, being able to convert malate to pyruvate and CO2 with the reduction of either NAD or NADP, and displays distinctive kinetic mechanisms depending on the relative concentration of the substrates. AYWB-ME activity was strictly modulated by the ATP/ADP ratio, a feature which has not been found in other ME isoforms characterized to date. In addition, we found that the 'Ca. Phytoplasma' AYWB PduL-like enzyme (AYWB-PduL) harbours phosphotransacetylase activity, being able to convert acetyl-CoA to acetyl phosphate downstream of pyruvate. ATP also inhibited AYWB-PduL activity, as with AYWB-ME, and the product of the reaction catalysed by AYWB-PduL, acetyl phosphate, stimulated AYWB-ME activity. Overall, our data indicate that AYWB-ME and AYWB-PduL activities are finely coordinated by common metabolic signals, like ATP/ADP ratios and acetyl phosphate, which support their participation in energy (ATP) and reducing power [NAD(P)H] generation from malate in phytoplasmas.
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Affiliation(s)
- Mariana Saigo
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| | - Adrián Golic
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| | - Clarisa E Alvarez
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| | - Carlos S Andreo
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| | - Saskia A Hogenhout
- Department of Cell and Developmental Biology, The John Innes Centre, Norwich NR4 7UH, UK
| | - María A Mussi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| | - María F Drincovich
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI- CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000 Rosario, Argentina
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Zuljan FA, Repizo GD, Alarcon SH, Magni C. α-Acetolactate synthase of Lactococcus lactis contributes to pH homeostasis in acid stress conditions. Int J Food Microbiol 2014; 188:99-107. [DOI: 10.1016/j.ijfoodmicro.2014.07.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 06/03/2014] [Accepted: 07/16/2014] [Indexed: 10/25/2022]
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21
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Repizo GD, Espariz M, Blancato VS, Suárez CA, Esteban L, Magni C. Genomic comparative analysis of the environmental Enterococcus mundtii against enterococcal representative species. BMC Genomics 2014; 15:489. [PMID: 24942651 PMCID: PMC4076982 DOI: 10.1186/1471-2164-15-489] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 06/02/2014] [Indexed: 11/30/2022] Open
Abstract
Background Enterococcus mundtii is a yellow-pigmented microorganism rarely found in human infections. The draft genome sequence of E. mundtii was recently announced. Its genome encodes at least 2,589 genes and 57 RNAs, and 4 putative genomic islands have been detected. The objective of this study was to compare the genetic content of E. mundtii with respect to other enterococcal species and, more specifically, to identify genes coding for putative virulence traits present in enterococcal opportunistic pathogens. Results An in-depth mining of the annotated genome was performed in order to uncover the unique properties of this microorganism, which allowed us to detect a gene encoding the antimicrobial peptide mundticin among other relevant features. Moreover, in this study a comparative genomic analysis against commensal and pathogenic enterococcal species, for which genomic sequences have been released, was conducted for the first time. Furthermore, our study reveals significant similarities in gene content between this environmental isolate and the selected enterococci strains (sharing an “enterococcal gene core” of 805 CDS), which contributes to understand the persistence of this genus in different niches and also improves our knowledge about the genetics of this diverse group of microorganisms that includes environmental, commensal and opportunistic pathogens. Conclusion Although E. mundtii CRL1656 is phylogenetically closer to E. faecium, frequently responsible of nosocomial infections, this strain does not encode the most relevant relevant virulence factors found in the enterococcal clinical isolates and bioinformatic predictions indicate that it possesses the lowest number of putative pathogenic genes among the most representative enterococcal species. Accordingly, infection assays using the Galleria mellonella model confirmed its low virulence. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-489) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | - Christian Magni
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET) and Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario S2002LRK, Argentina.
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22
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Biochemical and genetic characterization of the Enterococcus faecalis oxaloacetate decarboxylase complex. Appl Environ Microbiol 2013; 79:2882-90. [PMID: 23435880 DOI: 10.1128/aem.03980-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterococcus faecalis encodes a biotin-dependent oxaloacetate decarboxylase (OAD), which is constituted by four subunits: E. faecalis carboxyltransferase subunit OadA (termed Ef-A), membrane pump Ef-B, biotin acceptor protein Ef-D, and the novel subunit Ef-H. Our results show that in E. faecalis, subunits Ef-A, Ef-D, and Ef-H form a cytoplasmic soluble complex (termed Ef-AHD) which is also associated with the membrane. In order to characterize the role of the novel Ef-H subunit, coexpression of oad genes was performed in Escherichia coli, showing that this subunit is vital for Ef-A and Ef-D interaction. Diminished growth of the oadA and oadD single deletion mutants in citrate-supplemented medium indicated that the activity of the complex is essential for citrate utilization. Remarkably, the oadB-deficient strain was still capable of growing to wild-type levels but with a delay during the citrate-consuming phase, suggesting that the soluble Ef-AHD complex is functional in E. faecalis. These results suggest that the Ef-AHD complex is active in its soluble form, and that it is capable of interacting in a dynamic way with the membrane-bound Ef-B subunit to achieve its maximal alkalinization capacity during citrate fermentation.
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Fine-tuned transcriptional regulation of malate operons in Enterococcus faecalis. Appl Environ Microbiol 2012; 78:1936-45. [PMID: 22247139 DOI: 10.1128/aem.07280-11] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Enterococcus faecalis, the mae locus is constituted by two putative divergent operons, maePE and maeKR. The first operon encodes a putative H(+)/malate symporter (MaeP) and a malic enzyme (MaeE) previously shown to be essential for malate utilization in this bacterium. The maeKR operon encodes two putative proteins with significant similarity to two-component systems involved in sensing malate and activating its assimilation in bacteria. Our transcriptional and genetic assays showed that maePE and maeKR are induced in response to malate by the response regulator MaeR. In addition, we observed that both operons were partially repressed in the presence of glucose. Accordingly, the cometabolism of this sugar and malate was detected. The binding of the complex formed by CcpA and its corepressor P-Ser-HPr to a cre site located in the mae region was demonstrated in vitro and explains the carbon catabolite repression (CCR) observed for the maePE operon. However, our results also provide evidence for a CcpA-independent CCR mechanism regulating the expression of both operons. Finally, a biomass increment of 40 or 75% was observed compared to the biomass of cells grown only on glucose or malate, respectively. Cells cometabolizing both carbon sources exhibit a higher rate of glucose consumption and a lower rate of malate utilization. The growth improvement achieved by E. faecalis during glucose-malate cometabolism might explain why this microorganism employs different regulatory systems to tightly control the assimilation of both carbon sources.
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Suárez CA, Blancato VS, Poncet S, Deutscher J, Magni C. CcpA represses the expression of the divergent cit operons of Enterococcus faecalis through multiple cre sites. BMC Microbiol 2011; 11:227. [PMID: 21989394 PMCID: PMC3198936 DOI: 10.1186/1471-2180-11-227] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 10/11/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In Enterococcus faecalis the genes encoding the enzymes involved in citrate metabolism are organized in two divergent operons, citHO and oadHDB-citCDEFX-oadA-citMG (citCL locus). Expression of both operons is specifically activated by adding citrate to the medium. This activation is mediated by binding of the GntR-like transcriptional regulator (CitO) to the cis-acting sequences located in the cit intergenic region. Early studies indicated that citrate and glucose could not be co-metabolized suggesting some form of catabolite repression, however the molecular mechanism remained unknown. RESULTS In this study, we observed that the citHO promoter is repressed in the presence of sugars transported by the Phosphoenolpyruvate:carbohydrate Phosphotranserase System (PTS sugars). This result strongly suggested that Carbon Catabolic Repression (CCR) impedes the expression of the activator CitO and the subsequent induction of the cit pathway. In fact, we demonstrate that CCR is acting on both promoters. It is partially relieved in a ccpA-deficient E. faecalis strain indicating that a CcpA-independent mechanism is also involved in regulation of the two operons. Furthermore, sequence analysis of the citH/oadH intergenic region revealed the presence of three putative catabolite responsive elements (cre). We found that they are all active and able to bind the CcpA/P-Ser-HPr complex, which downregulates the expression of the cit operons. Systematic mutation of the CcpA/P-Ser-HPr binding sites revealed that cre1 and cre2 contribute to citHO repression, while cre3 is involved in CCR of citCL. CONCLUSION In conclusion, our study establishes that expression of the cit operons in E. faecalis is controlled by CCR via CcpA-dependent and -independent mechanisms.
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Affiliation(s)
- Cristian A Suárez
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, (S2002LRK) Rosario, Argentina
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